About

Jean E. Schwarzbauer, Ph.D., is the Eugene Higgins Professor of Molecular Biology at Princeton University. Her research focuses on extracellular matrix (ECM) assembly and cell-matrix interactions in normal and pathogenic situations, including cartilage development, kidney fibrosis, tumor formation, and tissue repair and regeneration. She investigates the mechanisms governing the assembly of the ECM protein fibronectin and its role in directing the assembly of other ECM proteins to form a definitive matrix. Her work has elucidated key steps in fibronectin fibril assembly, its interactions with integrin receptors and other ECM components, and the molecular changes involved in matrix assembly, including conformational changes and clustering of fibronectins. She has also studied how deficiencies in matrix composition relate to developmental defects and diseases such as cancer and fibrosis. Her recent discovery of a mutation in human FN1 associated with skeletal dysplasia provides a new model to study fibronectin's role in morphogenesis and differentiation. Additionally, her research explores how elevated glucose levels influence ECM-related gene expression in fibrosis and develops biomaterials for tissue engineering and regenerative medicine, including nerve regeneration strategies. Dr. Schwarzbauer has published over 125 papers, holds several patents, and contributes to the scientific community through service on various boards, panels, and editorial roles.

Research topics

• Cell biology
• Biology
• Chemistry
• Biophysics
• Biochemistry

Selected publications

• In Memoriam: Richard O. Hynes (1944–2026)

  Matrix Biology · 2026-03-13

  articleSenior author
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• Fibronectin matrix assembly at a glance

  Journal of Cell Science · 2025-03-15 · 14 citations

  reviewOpen accessSenior author

  The organization and mechanics of extracellular matrix (ECM) protein polymers determine tissue structure and function. Secreted ECM components are assembled into polymers via a cell-mediated process. The specific mechanisms that cells use for assembly are crucial for generating tissue-appropriate matrices. Fibronectin (FN) is a ubiquitous and abundant ECM protein that is assembled into a fibrillar matrix by a receptor-mediated process, and the FN matrix provides a foundation for incorporation of many other proteins into the ECM. In this Cell Science at a Glance article and the accompanying poster, we describe the domain organization of FN and the events that initiate and propagate a stable insoluble network of FN fibrils. We also discuss intracellular pathways that regulate FN assembly and the impact of changes in assembly on disease progression.

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• A novel fibronectin-binding peptide reveals dynamic intermediate structures during matrix assembly

  Scientific Reports · 2025-12-24

  articleOpen accessSenior author

  The extracellular matrix (ECM) is an expansive network of polymers that regulates cell adhesion, migration, and tissue morphogenesis, and that becomes dysregulated in fibrotic disease states. Of the many ECM proteins, fibronectin (FN) is foundational and FN fibrils are instrumental in promoting deposition of many other ECM proteins. FN fibrils form by cell receptor-mediated polymerization of secreted FN dimers. To provide a deeper understanding of the FN assembly process, we sought to identify FN-binding peptides that could be used to target FN during matrix assembly. Here we report the isolation of a FN-binding peptide, S2, by M13 phage display. When displayed within a GST-S2-EGFP fusion protein, S2 directs incorporation of the fluorescent fusion protein into FN fibrils during fibroblast matrix assembly, enabling direct visualization of fibril formation and accumulation. The S2 fusion protein remains stably associated with FN in decellularized matrices. Live cell imaging with GST-S2-EGFP revealed events in matrix formation and maturation and highlighted distinct features of FN assembly such as nascent fibril nucleation and elongation from coalescing FN aggregates. This S2 peptide fusion protein represents a new tool for real-time analysis of the ECM, for generation of fluorescent scaffolds, and for directing functional proteins to FN matrix.

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• Identification of a fibronectin-binding protein signature associated with idiopathic pulmonary fibrosis

  Cells and Development · 2024-07-20 · 11 citations

  articleOpen accessSenior authorCorresponding
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• Increased basal fibronectin is sufficient to promote excess endothelial cell matrix assembly causing localized barrier dysfunction

  Molecular Biology of the Cell · 2024-07-24 · 10 citations

  articleOpen accessSenior author

  Endothelial cell behavior is regulated by subendothelial extracellular matrix (ECM). The ECM protein fibronectin (FN) is rare in healthy blood vessels but accumulates in disease accompanied by endothelial dysfunctions. Here, we report that excess assembly of FN disrupts key endothelial functions. We mimicked increased FN expression as in diseased stroma by providing exogenous FN basally in a Transwell insert and found dose-dependent upregulation of subendothelial FN matrix assembly. Taking advantage of discontinuous matrix assembly by endothelial cells, we show correlations between regional increases in FN matrix and disruptions in endothelial cell morphology, VE-cadherin junctions, and the cell cycle, all of which were not changed in FN-deficient regions of the monolayer. These changes affected endothelial barrier function with increased monolayer permeability exposing basal regions of high FN matrix and permitting FN-dependent adhesion of MDA-MB-231 tumor cells from the apical side of the monolayer. FN matrix accumulation was quick and increases in FN matrix preceded all other changes in the endothelium. Therefore, subendothelial accumulation of FN matrix is a cause, not an effect, of endothelial monolayer disorganization and leakiness. Regulating FN accumulation in the subendothelial space could be an important target for controlling progression of fibrosis and related diseases.

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• Extracellular matrix composition affects outgrowth of dendrites and dendritic spines on cortical neurons

  Frontiers in Cellular Neuroscience · 2023-06-14 · 7 citations

  articleOpen accessSenior authorCorresponding

  The composition of the extracellular matrix (ECM) in nervous tissue plays an important role in controlling neuronal outgrowth and synapse development. Changes in both protein and glycosaminoglycan components of the ECM occur with tissue injury and may affect neuron growth. To investigate neuron responses to alterations in fibronectin (FN), a major component of the wound ECM, we grew cortical neurons on cell-derived decellularized matrices composed of wild type FN (FN +/+ ) or of a mutant form of FN (FN Δ/+ ) from which the III 13 heparin-binding site had been deleted by CRISPR-Cas 9 gene editing. The most significant effect of the mutant FN was a reduction in dendrite outgrowth. Not only were dendrites shorter on mutant FN Δ/+ -collagen (COL) matrix than on wild type (FN +/+ -COL) matrix, but the number of dendrites and dendritic spines per neuron and the spine densities were also dramatically reduced on FN Δ/+ -COL matrices. Mass spectrometry and immunostaining identified a reduction in tenascin-C (TN-C) levels in the mutant matrix. TN-C is an ECM protein that binds to the III 13 site of FN and modulates cell-matrix interactions and has been linked to dendrite development. We propose that TN-C binding to FN in the wound matrix supports dendrite and spine development during repair of damaged neural tissue. Overall, these results show that changes in ECM composition can dramatically affect elaboration of neurites and support the idea that the ECM microenvironment controls neuron morphology and connectivity.

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• Supplementary Figures 1-4 from Fibronectin Expression Modulates Mammary Epithelial Cell Proliferation during Acinar Differentiation

  2023-03-30

  preprintOpen accessSenior author

  Supplementary Figures 1-4 from Fibronectin Expression Modulates Mammary Epithelial Cell Proliferation during Acinar Differentiation

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• Nucleation of fibronectin fibril assembly requires binding between heparin and the 13th type III module of fibronectin

  Journal of Biological Chemistry · 2023-03-16 · 8 citations

  articleOpen accessSenior authorCorresponding

  Fibronectin (FN), a critical component of the extracellular matrix, is assembled into fibrils through a cell-mediated process. Heparan sulfate (HS) binds to the III13 module of FN, and fibroblasts lacking this glycosaminoglycan exhibit reduced FN fibril assembly. To determine if HS depends on III13 to control FN assembly, we deleted both III13 alleles in NIH 3T3 cells using the CRISPR-Cas9 system. ΔIII13 cells assembled fewer FN matrix fibrils and less DOC-insoluble FN matrix than wildtype cells. Little if any mutant FN matrix was assembled when purified ΔIII13 FN was provided to Chinese hamster ovary (CHO) cells, showing that lack of III13 caused the deficiency in assembly by ΔIII13 cells. Addition of heparin promoted the assembly of wildtype FN by CHO cells, but it had no effect on the assembly of ΔIII13 FN. Furthermore, heparin binding stabilized the folded conformation of III13 and prevented it from self-associating with increasing temperature suggesting that stabilization by HS/heparin binding might regulate interactions between III13 and other FN modules. This effect would be particularly important at matrix assembly sites where our data show that ΔIII13 cells require both exogenous wildtype FN and heparin in the culture medium to maximize assembly site formation. Our results show that heparin-promoted growth of fibril nucleation sites is dependent on III13. We conclude that HS/heparin binds to III13 to promote and control the nucleation and development of FN fibrils. Fibronectin (FN), a critical component of the extracellular matrix, is assembled into fibrils through a cell-mediated process. Heparan sulfate (HS) binds to the III13 module of FN, and fibroblasts lacking this glycosaminoglycan exhibit reduced FN fibril assembly. To determine if HS depends on III13 to control FN assembly, we deleted both III13 alleles in NIH 3T3 cells using the CRISPR-Cas9 system. ΔIII13 cells assembled fewer FN matrix fibrils and less DOC-insoluble FN matrix than wildtype cells. Little if any mutant FN matrix was assembled when purified ΔIII13 FN was provided to Chinese hamster ovary (CHO) cells, showing that lack of III13 caused the deficiency in assembly by ΔIII13 cells. Addition of heparin promoted the assembly of wildtype FN by CHO cells, but it had no effect on the assembly of ΔIII13 FN. Furthermore, heparin binding stabilized the folded conformation of III13 and prevented it from self-associating with increasing temperature suggesting that stabilization by HS/heparin binding might regulate interactions between III13 and other FN modules. This effect would be particularly important at matrix assembly sites where our data show that ΔIII13 cells require both exogenous wildtype FN and heparin in the culture medium to maximize assembly site formation. Our results show that heparin-promoted growth of fibril nucleation sites is dependent on III13. We conclude that HS/heparin binds to III13 to promote and control the nucleation and development of FN fibrils. The extracellular matrix (ECM) is a cell-assembled network of glycoproteins, polysaccharides, and collagens that is essential for all tissue development and repair. Fibronectin (FN), a ubiquitous glycoprotein, forms fibrils that are critical to the functioning of the ECM (1Singh P. Carraher C. Schwarzbauer J.E. Assembly of fibronectin extracellular matrix.Annu. Rev. Cell Dev. Biol. 2010; 26: 397-419Crossref PubMed Scopus (663) Google Scholar). Fibrils polymerize through FN-FN interactions, and recent evidence has implicated the ECM glycosaminoglycan (GAG) heparan sulfate (HS) in this process (2Raitman I. Huang M.L. Williams S.A. Friedman B. Godula K. Schwarzbauer J.E. Heparin-fibronectin interactions in the development of extracellular matrix insolubility.Matrix Biol. 2018; 67: 107-122Crossref PubMed Scopus (21) Google Scholar). Here we seek to understand how HS interacts with FN to control fibril assembly. Development of the FN matrix proceeds through a stepwise process that begins when secreted FN binds to the α5β1 integrin receptor at the cell surface. Cell contractility then imparts a force through the integrin that causes the bound FN to unfold and expose intermolecular FN-binding sites located throughout the molecule. Over time, FN molecules build up at the cell surface and association between these exposed sites forms nascent fibrils that develop into a deoxycholate (DOC)-insoluble fibrillar network (3Mao Y. Schwarzbauer J.E. Fibronectin fibrillogenesis, a cell-mediated matrix assembly process.Matrix Biol. 2005; 24: 389-399Crossref PubMed Scopus (627) Google Scholar). Disruption of this process can be catastrophic, leading to fibrosis, scarring, bone defects, and tumor invasion while loss of FN in mice causes embryonic lethality (1Singh P. Carraher C. Schwarzbauer J.E. Assembly of fibronectin extracellular matrix.Annu. Rev. Cell Dev. Biol. 2010; 26: 397-419Crossref PubMed Scopus (663) Google Scholar, 4George E.L. Georges-Labouesse E.N. Patel-King R.S. Rayburn H. Hynes R.O. Defects in mesoderm, neural tube and vascular development in mouse embryos lacking fibronectin.Development. 1993; 119: 1079-1091Crossref PubMed Google Scholar). Extracellular and transmembrane proteoglycans decorated with HS chains are abundant at the cell surface and in the ECM (5Sarrazin S. Lamanna W.C. Esko J.D. Heparan sulfate proteoglycans.Cold Spring Harb. Perspect. Biol. 2011; 3a004952Crossref PubMed Scopus (1002) Google Scholar). FN contains three different binding sites for HS; however, the HepII domain within type III repeats 12 to 14 has the highest affinity at physiological salt concentration (6Hynes R.O. Fibronectins. Springer, New York, NY1990Crossref Google Scholar). Interestingly, the HepII domain is overrepresented in the DOC-insoluble matrix and cells lacking HS assemble less FN matrix. This deficiency can be rescued, however, by treatment with an exogenous form of HS called heparin (7Hill K.E. Lovett B.M. Schwarzbauer J.E. Heparan sulfate is necessary for the early formation of nascent fibronectin and collagen I fibrils at matrix assembly sites.J. Biol. Chem. 2022; 298: 101479Abstract Full Text Full Text PDF PubMed Scopus (6) Google Scholar). Based on these and other findings, we hypothesized that binding between HS and HepII regulates fibril formation by recruiting FN dimers to cell surface assembly sites. To test this hypothesis, we deleted the III13 module, FN’s main heparin-binding site, in both alleles of FN1 in NIH 3T3 mouse fibroblast cells using the CRISPR-Cas9 system. Mutant FN produced by these ΔIII13 cells was deficient in fibril assembly and could not be rescued by the addition of heparin. Heparin binding to isolated III13 stabilized the folded conformation of this module to heat denaturation and prevented it from self-associating. Analysis of the FN requirements for matrix assembly site formation by ΔIII13 cells identified a role for heparin in promoting fibril nucleation in a III13-dependent manner. CRISPR-Cas9 gene editing was used to delete two III13 exons and the intervening intron from the FN1 gene in NIH 3T3 mouse fibroblast cells. Two guide RNAs and Cas9-GFP were targeted to the introns flanking the III13 exons (Fig. 1A). Cas9-GFP expressing single cells were then isolated by fluorescence-activated cell sorting, expanded, and screened by PCR of genomic DNA using primers in exon 2 of III12 and exon 1 of III14. The expected PCR product size was 985 bp for a III13 deletion and 2059 bp for wildtype (WT). PCR of genomic DNA from one colony, hereafter referred to as ΔIII13, produced a single band at 985 bp, indicating homozygous deletion of the III13 exons (Fig. 1B). To confirm that ΔIII13 FN is expressed, PCR was performed on WT and ΔIII13 cDNA and produced single bands at the expected 520 bp for WT cDNA and the expected 252 bp for ΔIII13 cDNA (Fig. 1C). Sequencing of the ΔIII13 cDNA product confirmed an in-frame deletion with a DNA sequence across the junction of GAGA/CCATC, translating to an amino acid sequence of ETI. Differences in FN expression levels between cell types could result in different FN matrix levels. Therefore, to determine whether WT and ΔIII13 cells express similar amounts of FN, we analyzed SDS cell lysates and cell-conditioned media from subconfluent cells in which FN is either intracellular or secreted into the medium but not yet assembled into fibrils. Immunoblots showed similar levels of FN in both cellular and media fractions (Fig. 1D). Therefore, FN expression and synthesis are not adversely affected by deletion of III13. FN matrix assembly was assessed by immunofluorescence imaging and DOC insolubility assays where nascent DOC-soluble FN is separated from stable DOC-insoluble FN (8McKeown-Longo P.J. Mosher D.F. Binding of plasma fibronectin to cell layers of human skin fibroblasts.J. Cell Biol. 1983; 97: 466-472Crossref PubMed Scopus (226) Google Scholar). FN matrix staining of confluent cells was significantly lower in ΔIII13 compared with WT cells (Fig. 2, A and B). Furthermore, wildtype cells assembled DOC-insoluble FN while ΔIII13 cells (Fig. Interestingly, ΔIII13 FN was in the medium than WT FN indicating that ΔIII13 cells not assemble mutant FN into a stable matrix. ΔIII13 FN in the medium suggesting that the III13 module is necessary for formation of the FN matrix. of assembly is not to a deficiency in ΔIII13 FN binding to cell to with WT FN or ΔIII13 FN showed no The in FN matrix assembly by ΔIII13 cells was not to reduced integrin expression PCR data that levels in ΔIII13 cells are than in wildtype cells. any in levels not result in FN binding to binding affinity Y. K. Cell Biol. PubMed Scopus Google showed amounts of WT FN binding to wildtype and ΔIII13 cells (Fig. Furthermore, ΔIII13 cells with WT FN to the medium FN matrix staining similar to that of WT cells (Fig. showing that ΔIII13 cells are to assemble WT FN and the that the in assembly is to mutant FN. To determine whether III13 is for FN assembly, ΔIII13 FN purified from ΔIII13 NIH 3T3 cell medium was to Chinese hamster ovary cells and to assemble this FN was by immunofluorescence imaging and DOC insolubility cells not FN (2Raitman I. Huang M.L. Williams S.A. Friedman B. Godula K. Schwarzbauer J.E. Heparin-fibronectin interactions in the development of extracellular matrix insolubility.Matrix Biol. 2018; 67: 107-122Crossref PubMed Scopus (21) Google any matrix in this is from the FN. FN matrix staining was significantly in cells with exogenous WT FN compared with exogenous ΔIII13 FN (Fig. A and DOC-insoluble FN matrix was significantly different with WT than ΔIII13 FN matrix (Fig. Therefore, cells assemble FN that III13. heparin binds to HepII and FN assembly by NIH 3T3 cells (2Raitman I. Huang M.L. Williams S.A. Friedman B. Godula K. Schwarzbauer J.E. Heparin-fibronectin interactions in the development of extracellular matrix insolubility.Matrix Biol. 2018; 67: 107-122Crossref PubMed Scopus (21) Google Scholar, K.E. Lovett B.M. Schwarzbauer J.E. Heparan sulfate is necessary for the early formation of nascent fibronectin and collagen I fibrils at matrix assembly sites.J. Biol. Chem. 2022; 298: 101479Abstract Full Text Full Text PDF PubMed Scopus (6) Google Scholar). To test whether III13 is important for this effect on assembly, heparin was to cells with either WT or ΔIII13 FN. The heparin treatment significantly FN matrix staining (Fig. A and and DOC-insoluble FN (Fig. in cells with WT FN but had no effect on cells with ΔIII13 FN (Fig. Therefore, the effect of heparin FN indicating that this module is critical for heparin of fibril assembly. Heparin binding to III13 could a in the module that to with other FN modules. types I and FN type III lack and and of fibronectin type III and the for and of and S. PubMed Scopus Google Scholar, the folded of fibronectin type III in fibrils by Biol. Chem. 2011; Full Text Full Text PDF PubMed Scopus Google Scholar). This type III the for that binding The of to PubMed Scopus Google Scholar). has that of to of the type III could interactions with in other through C. K. The between the type III domain from fibronectin and PubMed Scopus (6) Google Scholar, S.A. S. C. of fibrils by of a fibronectin type III Biol. PubMed Scopus Google Scholar). types of interactions could fibril and if assembly proceeds The of the folded conformation of III13 in with or heparin treatment was by from an in the of the The of is dependent on the of from when in the to when in by Biol. Scopus Google Scholar). Therefore, the as the module The of III13 heparin with increasing showing an at and at with a temperature of (Fig. a temperature was to the in the of heparin to with a of with an concentration of a of similar as heparin and but with a different a similar to III13 with a The in the with heparin that heparin binding it from as temperature of the module from could and interactions between modules. was used to determine whether the by heparin on III13 the of the module to The of III13 in at was (Fig. the III13 was the stable when it Interestingly, this the temperature that III13 to unfold in the suggesting that of with heparin but not acid prevented III13 from self-associating into as temperature showing a between stabilization by heparin and control of III13 of interactions between FN would be fibril nucleation when FN molecules at the cell surface in association with matrix assembly sites. nucleation at matrix assembly sites when cell contractility FN-binding sites and interactions between the assembly domain and type III (1Singh P. Carraher C. Schwarzbauer J.E. Assembly of fibronectin extracellular matrix.Annu. Rev. Cell Dev. Biol. 2010; 26: 397-419Crossref PubMed Scopus (663) Google Scholar). To test whether heparin binding to III13 these interactions, WT or ΔIII13 NIH 3T3 cells were on with either WT FN or ΔIII13 FN and matrix assembly sites were with a of FN WT cells matrix assembly sites of similar size and on both WT and ΔIII13 FN (Fig. indicating that heparin binding of the FN is not essential for this process. ΔIII13 cells had significantly and matrix assembly sites than WT cells on both (Fig. Therefore, produced and secreted ΔIII13 FN not with matrix assembly sites and the of a WT FN is not to this The amounts of FN secreted by WT and ΔIII13 cells are similar the in matrix assembly site formation is not to of FN. could be a reduced affinity between ΔIII13 FN and other at the sites. a deficiency might be by FN in the Addition of ΔIII13 FN to ΔIII13 cells on a ΔIII13 FN not matrix assembly site formation to no FN or to WT cells on a WT FN with no exogenous FN (Fig. and the other addition of WT FN to the medium of ΔIII13 cells on a ΔIII13 FN in ΔIII13 FN addition to ΔIII13 cells on a WT FN significantly matrix assembly sites to similar levels (Fig. and Interestingly, this FN caused a of assembly sites (Fig. these results show that ΔIII13 cells require an exogenous of FN in the culture medium as as a of FN either in the culture medium or in the surface for of matrix assembly site formation. WT cells, FN is but for ΔIII13 cells, FN not with matrix assembly sites an exogenous is To determine whether the for FN III13 in matrix assembly site formation depends on with we analyzed the of heparin to ΔIII13 cells on either a ΔIII13 FN with exogenous WT FN or on a WT FN with exogenous ΔIII13 FN. Interestingly, when WT FN was in the heparin significantly matrix assembly site staining to WT levels (Fig. and but had no effect on staining when ΔIII13 FN was in the medium (Fig. and results confirm that heparin not the assembly of ΔIII13 FN. Furthermore, the effect of heparin on whether WT FN or mutant FN is in the medium that heparin the of exogenous FN to matrix assembly sites. This our that the role of HS/heparin at this early is to secreted FN molecules at the cell surface to the concentration and promote fibril Heparan sulfate was implicated in the early of FN fibril assembly using of an for HS synthesis (7Hill K.E. Lovett B.M. Schwarzbauer J.E. Heparan sulfate is necessary for the early formation of nascent fibronectin and collagen I fibrils at matrix assembly sites.J. Biol. Chem. 2022; 298: 101479Abstract Full Text Full Text PDF PubMed Scopus (6) Google Scholar). we show that HS through binding to the III13 module of FN. This module was deleted from both alleles of the FN gene in NIH 3T3 fibroblasts using the CRISPR-Cas9 system. The ΔIII13 cells assembled fewer FN fibrils and had levels of DOC-insoluble matrix. purified ΔIII13 FN was not assembled by CHO cells, which are to assemble FN fibrils but not FN. these results show that the effect of HS/heparin on FN assembly is dependent on III13. the of mutant and WT FN on matrix assembly site formation by ΔIII13 cells, we that heparin could matrix assembly sites but when WT FN not mutant FN, was to the cell Therefore, through with heparin FN from the medium to sites of fibril nucleation at the cell surface. This the addition of FN to matrix assembly sites and the growth of fibrils. the time, binding between heparin and III13 the module and which could to interactions assembly. assembly is through interactions between type I that up the assembly domain and other FN-binding sites within type III (1Singh P. Carraher C. Schwarzbauer J.E. Assembly of fibronectin extracellular matrix.Annu. Rev. Cell Dev. Biol. 2010; 26: 397-419Crossref PubMed Scopus (663) Google Scholar). interactions are promoted when binding and integrin into and matrix assembly sites FN III13 is with the domain of FN for and formation Hynes R.O. Fibronectin regulates assembly of and in cells the heparin-binding site in Biol. PubMed Scopus Google and a HepII domain of FN can fibril formation when H. Fibronectin the heparin binding domain of Biol. Chem. Full Text Full Text PDF PubMed Scopus Google Scholar). are transmembrane heparan sulfate proteoglycans that to the HepII implicated binding in cell S. Mosher D.F. with in a in the assembly of and S. PubMed Scopus Google Scholar, S.A. Biol. Chem. Full Text Full Text PDF PubMed Scopus Google and expression in FN matrix assembly Schwarzbauer J.E. for sulfate and the sulfate in fibronectin matrix Cell Biol. PubMed Scopus Google Scholar). can intracellular of cell and PubMed Scopus Google suggesting that the role of HepII in and FN assembly is to through Our results show that HS/heparin binding to HepII has FN at sites of fibril for this from our showing that the heparin be to FN molecules to an effect on early FN fibril assembly (2Raitman I. Huang M.L. Williams S.A. Friedman B. Godula K. Schwarzbauer J.E. Heparin-fibronectin interactions in the development of extracellular matrix insolubility.Matrix Biol. 2018; 67: 107-122Crossref PubMed Scopus (21) Google Scholar, K.E. Lovett B.M. Schwarzbauer J.E. Heparan sulfate is necessary for the early formation of nascent fibronectin and collagen I fibrils at matrix assembly sites.J. Biol. Chem. 2022; 298: 101479Abstract Full Text Full Text PDF PubMed Scopus (6) Google and from data showing that the of HS chains on from to 1 to formation S. Heparan sulfate in cell Biol. Chem. 2010; Full Text Full Text PDF PubMed Scopus Google Scholar). Our data a in which the chains of secreted or FN molecules at the III13 and α5β1 where can with matrix assembly sites and fibril formation. Our but not any in FN assembly. in cell and fibril assembly, our results show that HS/heparin not to be to the cell surface in to this our HS could be to in the at the cell surface heparin fibril HS could be to within the the that different can regulate FN matrix assembly through a III13-dependent is that are in that to the cell surface fibril while could to fibril assembly in the between cells. HS/heparin binds III13 between A and of a and of human PubMed Google Scholar, Schwarzbauer J.E. of the heparin-binding site in Biol. Chem. Full Text PDF PubMed Google we no evidence of heparin-promoted of the A from the type III13 heparin binding stabilized III13 is in FN matrix assembly Schwarzbauer J.E. for sulfate and the sulfate in fibronectin matrix Cell Biol. PubMed Scopus Google and be for heparin stabilization of III13 that the had no is not to FN matrix assembly as sulfate was to no (7Hill K.E. Lovett B.M. Schwarzbauer J.E. Heparan sulfate is necessary for the early formation of nascent fibronectin and collagen I fibrils at matrix assembly sites.J. Biol. Chem. 2022; 298: 101479Abstract Full Text Full Text PDF PubMed Scopus (6) Google Scholar). FN molecules at the cell surface might the for interactions, which could be integrin binding and cell contractility FN from and expose binding sites. heparin binding to III13 prevented from the stabilization and reduced that HS/heparin might a role FN, fibril assembly by interactions that to fibrils. this HS/heparin could promote fibril assembly by the addition of secreted FN to matrix assembly sites while at the as a on FN a the of HS/heparin would that assembly proceeds in a and manner. for stabilization in addition to III13 the type III within B. B. role for integrin and sulfate proteoglycans in cell to the heparin III domain of of a heparin and cell binding sequence in Biol. Chem. Full Text Full Text PDF PubMed Scopus Google and the type I in S.A. of the domain of fibronectin with role of the of the type I Biol. Chem. Full Text Full Text PDF PubMed Scopus Google Scholar). heparin binding to the domain of FN, where is has to S.A. of fibronectin and and of the domain by PubMed Scopus Google Scholar). heparin stabilization could in III13. Interestingly, in the HepII domain and in are with single amino acid deletion fibronectin and causes with fibronectin of a PubMed Scopus Google Scholar, in FN1 with fibronectin S. PubMed Scopus Google and and loss of in and and Full Text Full Text PDF PubMed Scopus Google Scholar, Y. K. Y. of the heparan to of bone and Biol. Chem. 2010; Full Text Full Text PDF PubMed Scopus Google a between and NIH 3T3 mouse fibroblasts were in medium with cells were in medium and cells were for and to be for FN was purified from plasma and ΔIII13 FN was purified from ΔIII13 cell-conditioned medium affinity as Schwarzbauer J.E. The to the of plasma and cellular into Cell Biol. 119: PubMed Scopus Google Scholar). purified FN was into Heparin salt from and acid salt from were from and in of FN was purified from cells with a expressing the of FN and with used in this were FN and used were and of matrix assembly was The that intron that the FN III13 module were The intron sequence was into and the intron sequence was into were into guide by into as using the CRISPR-Cas9 PubMed Scopus Google Scholar). NIH 3T3 cells were at cells cells were with of and of 1 of in 1 at of medium was and cells were for at The medium was with 2 and cells were and the was to the for on a with a with of was by a and was through a and a data sorting, and data were performed with single cells were in of a of genomic DNA was for PCR using the in III12 exon in exon PCR were by was from cells and screened by Sequencing of was performed by A human III13 cDNA was by PCR using the primers that and sites at and sites were used to the cDNA into into cells and the was confirmed by with were by three through an cell at to The was isolated from the cell by affinity on and with in 2 The affinity was from III13 using III13 was purified from by affinity on with 1 and into 2 matrix NIH 3T3 fibroblasts were on to then and as (7Hill K.E. Lovett B.M. Schwarzbauer J.E. Heparan sulfate is necessary for the early formation of nascent fibronectin and collagen I fibrils at matrix assembly sites.J. Biol. Chem. 2022; 298: 101479Abstract Full Text Full Text PDF PubMed Scopus (6) Google Scholar, Y. Schwarzbauer J.E. of fibronectin matrix assembly by deletion of the type III Cell Biol. PubMed Scopus Google Scholar). cells were on to with FN and heparin as and then and amounts of exogenous WT and mutant FN levels were by of were in were using a with a FN were from the of of for Cell on with of WT FN or ΔIII13 FN was at of matrix assembly site subconfluent cells on were in culture medium were and with The matrix assembly site of cells was as (7Hill K.E. Lovett B.M. Schwarzbauer J.E. Heparan sulfate is necessary for the early formation of nascent fibronectin and collagen I fibrils at matrix assembly sites.J. Biol. Chem. 2022; 298: 101479Abstract Full Text Full Text PDF PubMed Scopus (6) Google Scholar). matrix assembly site was from at cells The of two or three in is NIH 3T3 cells and cells were as for and and cell fractions were with DOC as I. Y. Schwarzbauer J.E. Analysis of fibronectin matrix Cell Biol. PubMed Google Scholar). were separated on SDS with to and with or and (7Hill K.E. Lovett B.M. Schwarzbauer J.E. Heparan sulfate is necessary for the early formation of nascent fibronectin and collagen I fibrils at matrix assembly sites.J. Biol. Chem. 2022; 298: 101479Abstract Full Text Full Text PDF PubMed Scopus (6) Google Scholar). were with was performed on with in the were to The of Y. K. Cell Biol. PubMed Scopus Google was A of were in 2 2 2 1 1 of plasma FN. were for at temperature and then into was on of and at for were in SDS and then reduced and separated by on and from confluent wildtype and ΔIII13 fibroblasts was isolated using by with an J.E. gene expression and in Biol. PubMed Scopus Google Scholar). cDNA was and was performed as (7Hill K.E. Lovett B.M. Schwarzbauer J.E. Heparan sulfate is necessary for the early formation of nascent fibronectin and collagen I fibrils at matrix assembly sites.J. Biol. Chem. 2022; 298: 101479Abstract Full Text Full Text PDF PubMed Scopus (6) Google Scholar). was used for was performed using III13 was performed using the with a temperature control in 2 was with or acid to a concentration of on for in a and then from to increasing at 1 The was at and by the was a of to at To control for results were in a of at where a of the was performed with a using III13 was and as and then from to increasing 1 in a and were by a the of are as the of as in were performed using an test or a with data are within the The that no of with the of this We are to of the and to of the which is by the of New and an NIH We of the Schwarzbauer for B. K. and S. B. data B. and S. S. B. K. and B. K. and S. B. and S. S. S. B. and S. B. B. and S. B. K. and S. and This was by from of and the for the of to and other B. and K. H. were by an NIH to the of at The is the of the and not the of the of

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• Data from Fibronectin Expression Modulates Mammary Epithelial Cell Proliferation during Acinar Differentiation

  2023-03-30

  preprintOpen accessSenior author

  <div>Abstract<p>The mammary gland consists of a polarized epithelium surrounded by a basement membrane matrix that forms a series of branching ducts ending in hollow, sphere-like acini. Essential roles for the epithelial basement membrane during acinar differentiation, in particular laminin and its integrin receptors, have been identified using mammary epithelial cells cultured on a reconstituted basement membrane. Contributions from fibronectin, which is abundant in the mammary gland during development and tumorigenesis, have not been fully examined. Here, we show that fibronectin expression by mammary epithelial cells is dynamically regulated during the morphogenic process. Experiments with synthetic polyacrylamide gel substrates implicate both specific extracellular matrix components, including fibronectin itself, and matrix rigidity in this regulation. Alterations in fibronectin levels perturbed acinar organization. During acinar development, increased fibronectin levels resulted in overproliferation of mammary epithelial cells and increased acinar size. Addition of fibronectin to differentiated acini stimulated proliferation and reversed growth arrest of mammary epithelial cells negatively affecting maintenance of proper acinar morphology. These results show that expression of fibronectin creates a permissive environment for cell growth that antagonizes the differentiation signals from the basement membrane. These effects suggest a link between fibronectin expression and epithelial cell growth during development and oncogenesis in the mammary gland. [Cancer Res 2008;68(9):3185–92]</p></div>

  PublisherDOI

• Supplementary Figures 1-4 from Fibronectin Expression Modulates Mammary Epithelial Cell Proliferation during Acinar Differentiation

  2023-03-30

  preprintOpen accessSenior author

  Supplementary Figures 1-4 from Fibronectin Expression Modulates Mammary Epithelial Cell Proliferation during Acinar Differentiation

  PublisherDOI

Recent grants

• NIH Grant R01CA160611

  NIH · $1.6M · 2018

• Fibronectin-dependent mechanisms governing the assembly of a definitive extracellular matrix

  NIH · $1.7M · 2018–2024

• Predoctoral Training in Genetics and Molecular Biology

  NIH · $31.9M · 1977–2023

• NIH Grant R01CA044627

  NIH · $6.0M · 2011

• NIH Grant U54GM064346

  NIH · $106.5M · 2014

Frequent coauthors

• Richard O. Hynes

  Howard Hughes Medical Institute

  24 shared

• John W. Tamkun

  University of California, Santa Cruz

  19 shared

• Jeffrey Schwartz

  Loyola University Medical Center

  17 shared

• Adam J. Engler

  University of California, San Diego

  15 shared

• Siobhan Corbett

  14 shared

• Kim S. Midwood

  University of Oxford

  13 shared

• Henry C. Hsia

  Yale University

  11 shared

• J I Paul

  10 shared

Education

• PhD, Molecular Biology

  University of Wisconsin–Madison

  1980

• BS, Chemistry

  University of Wisconsin–Milwaukee

  1974

Awards & honors

• Peggy Wheelock Award for Excellence in Research, Mentoring,…