scholarly journals Cell attachment controls fibronectin and alpha 5 beta 1 integrin levels in fibroblasts. Implications for anchorage-dependent and -independent growth.

1992 ◽  
Vol 267 (12) ◽  
pp. 8186-8191 ◽  
Author(s):  
S.L. Dalton ◽  
E.E. Marcantonio ◽  
R.K. Assoian
Keyword(s):  
Cell Attachment ◽  
Beta 1 Integrin

scholarly journals Isolation of a highly specific ligand for the alpha 5 beta 1 integrin from a phage display library

1994 ◽  
Vol 124 (3) ◽  
pp. 373-380 ◽  
Author(s):  
E Koivunen ◽  
B Wang ◽  
E Ruoslahti
Keyword(s):  
Phage Display ◽  
Cyclic Peptide ◽  
Cell Attachment ◽  
Phage Display Library ◽  
Cell Binding ◽  
Rgd Peptides ◽  
Beta 1 Integrin ◽  
Alpha V Beta 3 ◽  
Integrin Ligand ◽  
Specific Ligand

Our previous studies showed that the alpha 5 beta 1 integrin selects cysteine pair-containing RGD peptides from a phage display library based on a random hexapeptide. We have therefore searched for more selective peptides for this integrin using a larger phage display library, where heptapeptides are flanked by cysteine residues, thus making the inserts potentially cyclic. Most of the phage sequences that bound to alpha 5 beta 1 (69 of 125) contained the RGD motif. Some of the heptapeptides contained an NGR motif. As the NGR sequence occurs in the cell-binding region of the fibronectin molecule, this sequence could contribute to the specific recognition of fibronectin by alpha 5 beta 1. Selection for high affinity peptides for alpha 5 beta 1 surprisingly yielded a sequence RRETAWA that does not bear obvious resemblance to known integrin ligand sequences. The synthetic cyclic peptide GACRRETAWACGA (*CRRETAWAC*) was a potent inhibitor of alpha 5 beta 1-mediated cell attachment to fibronectin. This peptide is nearly specific for the alpha 5 beta 1 integrin, because much higher concentrations were needed to inhibit the alpha v beta 1 integrin, and there was no effect on alpha v beta 3- and alpha v beta 5-mediated cell attachment to vitronectin. The peptide also did not bind to the alpha IIb beta 3 integrin. *CRRETAWAC* appears to interact with the same or an overlapping binding site in alpha 5 beta 1 as RGD, because cell attachment to *CRRETAWAC* coated on plastic was divalent cation dependent and could be blocked by an RGD-containing peptide. These results reveal a novel binding specificity in the alpha 5 beta 1 integrin.

scholarly journals Avian neural crest cell attachment to laminin: involvement of divalent cation dependent and independent integrins

Development ◽  
1991 ◽  
Vol 113 (4) ◽  
pp. 1069-1084 ◽  
Author(s):  
T. Lallier ◽  
M. Bronner-Fraser
Keyword(s):  
Neural Crest ◽  
Cell Attachment ◽  
Divalent Cations ◽  
Neural Crest Cell ◽  
Neural Crest Cells ◽  
Cell Interaction ◽  
Cell Binding ◽  
Cell Adherence ◽  
Beta 1 Integrin ◽  
Crest Cell

The mechanisms of neural crest cell interaction with laminin were explored using a quantitative cell attachment assay. With increasing substratum concentrations, an increasing percentage of neural crest cells adhere to laminin. Cell adhesion at all substratum concentrations was inhibited by the CSAT antibody, which recognizes the chick beta 1 subunit of integrin, suggesting that beta 1-integrins mediate neural crest cell interactions with laminin. The HNK-1 antibody, which recognizes a carbohydrate epitope, inhibited neural crest cell attachment to laminin at low coating concentrations (greater than 1 microgram ml-1; Low-LM), but not at high coating concentration of laminin (10 micrograms ml-1; High-LM). Attachment to Low-LM occurred in the absence of divalent cations, whereas attachment to High-LM required greater than 0.1 mM Ca2+ or Mn2+. Neural crest cell adherence to the E8 fragment of laminin, derived from its long arm, was similar to that on intact laminin at high and low coating concentrations, suggesting that this fragment contains the neural crest cell binding site(s). The HNK-1 antibody recognizes a protein of 165,000 Mr which is also found in immunoprecipitates using antibodies against the beta 1 subunit of integrin and is likely to be an integrin alpha subunit or an integrin-associated protein. Our results suggest that the HNK-1 epitope on neural crest cells is present on or associated with a novel or differentially glycosylated form of beta 1-integrin, which recognizes laminin in the apparent absence of divalent cations. We conclude that neural crest cells have at least two functionally independent means of attachment to laminin which are revealed at different substratum concentrations and/or conformations of laminin.

Stimulation of tyrosine phosphorylation of distinct proteins in response to antibody-mediated ligation and clustering of alpha 3 and alpha 6 integrins

1995 ◽  
Vol 108 (3) ◽  
pp. 1165-1174
Author(s):  
K. Jewell ◽  
C. Kapron-Bras ◽  
P. Jeevaratnam ◽  
S. Dedhar
Keyword(s):  
Tyrosine Kinase ◽  
Tyrosine Phosphorylation ◽  
Kinase Inhibitor ◽  
Cell Attachment ◽  
Umbilical Vein ◽  
Integrin Receptors ◽  
Human Prostate Carcinoma ◽  
Beta 1 Integrin ◽  
Umbilical Vein Endothelial Cells ◽  
Stimulation Of

The interaction of cells with components of the extracellular matrix through their integrin receptors results in the stimulation of tyrosine phosphorylation of several proteins, suggesting that these receptors play a key role in signal transduction. Here we report that antibody-mediated ligation and clustering of alpha 3 beta 1 and alpha 6 beta 1/alpha 6 beta 4 integrins resulted in the stimulation of tyrosine phosphorylation of proteins that are specific for each heterodimer. Thus, ligation and clustering of the alpha 3 beta 1 integrin on human prostate carcinoma cells (PC-3) and human umbilical vein endothelial cells (HUVEC) with anti-alpha 3 antibodies resulted in the stimulation of tyrosine phosphorylation of a 55 kDa protein. In contrast, ligation and clustering of the alpha 6 beta 1 integrin on these cells with anti-alpha 6 antibody resulted in the dramatic stimulation of tyrosine phosphorylation of a 90 kDa protein in addition to a 52 kDa protein, and ligation and clustering of alpha 5 beta 1 on HUVEC did not result in the apparent stimulation of tyrosine phosphorylation of any proteins. Clustering with anti-beta 1 antibodies triggered the tyrosine phosphorylation of all of these proteins, whereas ligation and clustering of PC-3 cells with an anti-beta 4 antibody resulted in the tyrosine phosphorylation of a distinct 62 kDa protein. Since the PC-3 cells express both alpha 6 beta 1 and alpha 6 beta 4, these data suggest that these two receptors can transduce distinct signals. All of the phosphorylations could be inhibited by treating the cells with Genistein, a tyrosine kinase inhibitor. Antibody-mediated ligation and clustering of integrins on the two types of cells did not result in the stimulation of tyrosine phosphorylation of pp125 focal adhesion kinase, although this was observed upon cell attachment and spreading on fibronectin, laminin and anti-alpha 3 monoclonal antibody. Collectively, these data demonstrate that cross-linking of different integrin heterodimers can stimulate tyrosine kinase activities, leading to the phosphorylation of distinct proteins, which are also different from those observed when cells are allowed to spread on a matrix.

scholarly journals Alpha 1 beta 1 integrin on neural crest cells recognizes some laminin substrata in a Ca(2+)-independent manner.

1992 ◽  
Vol 119 (5) ◽  
pp. 1335-1345 ◽  
Author(s):  
T Lallier ◽  
M Bronner-Fraser
Keyword(s):  
Neural Crest ◽  
Cell Attachment ◽  
Divalent Cations ◽  
Neural Crest Cell ◽  
Neural Crest Cells ◽  
Laminin Receptor ◽  
Adhesion Assay ◽  
Independent Manner ◽  
Preparation Conditions ◽  
Beta 1 Integrin

Neural crest cells migrate along pathways containing laminin and other extracellular matrix molecules. In the present study, we functionally and biochemically identify an alpha 1 beta 1 integrin heterodimer which bears the HNK-1 epitope on neural crest cells. Using a quantitative cell adhesion assay, we find that this heterodimer mediates attachment to laminin substrata prepared in the presence of Ca2+. Interestingly, neural crest cells bind to laminin-Ca2+ substrata in the presence or absence of divalent cations in the cell attachment medium. In contrast, the attachment of neural crest cells to laminin substrata prepared in the presence of EDTA, heparin, Mg2+, or Mn2+ requires divalent cations. Interactions with these laminin substrata are mediated by a different integrin heterodimer, since antibodies against beta 1 but not alpha 1 integrins inhibit neural crest cell attachment. Thus, the type of laminin substratum appears to dictate the choice of laminin receptor used by neural crest cells. The laminin conformation is determined by the ratio of laminin to Ca2+, though incorporation of heparin during substratum polymerization alters the conformation even in the presence of Ca2+. Once polymerized, the substratum appears stable, not being altered by soaking in either EDTA or divalent cations. Our findings demonstrate: (a) that the alpha 1 beta 1 integrin can bind to some forms of laminin in the absence of soluble divalent cations; (b) that substratum preparation conditions alter the conformation of laminin such that plating laminin in the presence of Ca2+ and/or heparin modulates its configuration; and (c) that neural crest cells utilize different integrins to recognize different laminin conformations.

scholarly journals The alpha 1/beta 1 and alpha 6/beta 1 integrin heterodimers mediate cell attachment to distinct sites on laminin.

1990 ◽  
Vol 110 (6) ◽  
pp. 2175-2184 ◽  
Author(s):  
D E Hall ◽  
L F Reichardt ◽  
E Crowley ◽  
B Holley ◽  
H Moezzi ◽  
...  
Keyword(s):  
Cell Attachment ◽  
Collagen Iv ◽  
Cellular Interactions ◽  
Beta 1 Integrin ◽  
Alpha Beta ◽  
Choriocarcinoma Cells ◽  
Mediate Cell ◽  
The Individual ◽  
A Site ◽  
Jar Cells

This study was undertaken to determine the roles of individual alpha/beta 1 integrin heterodimers in promoting cellular interactions with the different attachment-promoting domains of laminin (LN). To do this, antibodies to the integrin beta 1 subunit or to specific integrin alpha subunits were tested for effects on cell attachment to LN, to elastase fragments E1-4 and E1, derived from the short arms and core of LN's cruciform structure, and to fragment E8 derived from the long arm of this structure. The human JAR choriocarcinoma cells used in this study attached to LN and to fragments E1 and E8. Attachment to E1-4 required a much higher substrate coating concentration, suggesting that it is a poor substrate for JAR cell attachment. The ability of cells to attach to different LN domains suggested the presence of more than one LN receptor. These multiple LN receptors were shown to be beta 1 integrin heterodimers because antibodies to the integrin beta 1 subunit inhibited attachment of JAR cells to LN and its three fragments. To identify the individual integrin alpha/beta 1 heterodimers that mediate interactions with these LN domains, mAbs specific for individual beta 1 heterodimers in human cells were used to study JAR cell interactions with LN and its fragments. An anti-alpha 6/beta 1-specific mAb, GoH3, virtually eliminated cell attachment to E8 and partially inhibited attachment to E1 and intact LN. Thus the major alpha 6/beta 1 attachment domain is present in fragment E8. An alpha 1/beta 1-specific mAb (S2G3) strongly inhibited cell attachment to collagen IV and partially inhibited JAR attachment to LN fragment E1. Thus, the alpha 1/beta 1 heterodimer is a dual receptor for collagen IV and LN, interacting with LN at a site in fragment E1. In combination, the anti-alpha 1- and anti-alpha 6-specific antibodies completely inhibited JAR cell attachment to LN and fragment E1. Thus, the alpha 1/beta 1 and alpha 6/beta 1 integrin heterodimers each function as LN receptors and act together to mediate the interactions of human JAR choriocarcinoma cells with LN.

Anti-Fx1A antibody recognizes a beta 1-integrin on glomerular epithelial cells and inhibits adhesion and growth

1992 ◽  
Vol 262 (5) ◽  
pp. F770-F776 ◽  
Author(s):  
S. Adler ◽  
X. Chen
Keyword(s):  
Epithelial Cells ◽  
Cell Attachment ◽  
Normal Growth ◽  
Dependent Manner ◽  
Glomerular Permeability ◽  
Filtration Barrier ◽  
Glomerular Epithelial Cells ◽  
Beta 1 Integrin ◽  
Cell Matrix Interactions

Cell-matrix interactions play an important role in regulating cell growth and metabolic activity and potentially in maintaining the integrity of the glomerular filtration barrier. The effect of anti-Fx1A antibody (Ab), the pathogenetic Ab of passive Heymann nephritis, on the interaction of cultured rat glomerular visceral epithelial cells (GEC) with matrix components was examined in an effort to determine whether it affects cell adhesion. Affinity chromatography demonstrated that anti-Fx1A recognizes an alpha 3 beta 1-integrin-type matrix receptor on GEC. Anti-Fx1A inhibited the adhesion of GEC to several substrates (collagen IV approximately equal to collagen I less than laminin approximately equal to fibronectin) in a dose-dependent manner and produced reversible cell detachment and "rounding up" when added to adherent cells. Maximal inhibition of adhesion was similar with anti-Fx1A and anti-beta 1, and competition studies showed no additive effects between anti-Fx1A and anti-beta 1 in inhibiting adhesion, suggesting that the effect of anti-Fx1A on GEC adhesion is attributable to its anti-beta 1 activity. Anti-Fx1A Ab also inhibited the growth of GEC in culture without evidence of cytotoxicity, and cells resumed normal growth on removal of Ab. These studies suggest that anti-Fx1A Ab can bind to matrix receptors on GEC, resulting in inhibition of cell attachment and growth, as well as producing detachment of cells that are already adherent. Interference with GEC-glomerular basement membrane interactions in vivo might have significant effects on glomerular permeability to proteins.

scholarly journals The alpha v beta 1 integrin functions as a fibronectin receptor but does not support fibronectin matrix assembly and cell migration on fibronectin

1993 ◽  
Vol 122 (1) ◽  
pp. 235-242 ◽  
Author(s):  
Z Zhang ◽  
AO Morla ◽  
K Vuori ◽  
JS Bauer ◽  
RL Juliano ◽  
...  
Keyword(s):  
Cell Migration ◽  
Cell Attachment ◽  
Focal Adhesions ◽  
Cho Cell ◽  
Matrix Assembly ◽  
Fibronectin Receptor ◽  
Fibronectin Matrix ◽  
Beta 1 Integrin ◽  
Fibronectin Binding ◽  
Coated Surfaces

The fibronectin receptor, alpha 5 beta 1, has been shown to be required for fibronectin matrix assembly and plays an important role in cell migration on fibronectin. However, it is not clear whether other fibronectin binding integrins can take the place of alpha 5 beta 1 during matrix assembly and cell migration. To test this, we expressed the human alpha v subunit in the CHO cell line CHO-B2 that lacks the alpha 5 subunit. We found that the human alpha v combined with CHO cell beta 1 to form the integrin alpha v beta 1. Cells that expressed alpha v beta 1 attached to and spread well on fibronectin-coated dishes, but did so less well on vitronectin-coated dishes. This, along with other data, indicated that alpha v beta 1 functions as a fibronectin receptor in CHO-B2 cells. The alpha v beta 1-expressing cells failed to produce a fibronectin matrix or to migrate on fibronectin, although the same cells transfected with alpha 5 do produce a matrix and migrate on fibronectin. The affinity of the alpha v beta 1-expressing cells for fibronectin was fourfold lower than that of the alpha 5 beta 1-expressing cells. In addition, alpha v beta 1 was distributed diffusely throughout the cell surface, whereas alpha 5 beta 1 was localized to focal adhesions when cells were seeded onto fibronectin-coated surfaces. Thus, of the two fibronectin receptors, alpha v beta 1 and alpha 5 beta 1, only alpha 5 beta 1 supports fibronectin matrix assembly and promotes cell migration on fibronectin in the CHO-B2 cells. Possible reasons for this difference in the activities of alpha v beta 1 and alpha 5 beta 1 include the lower affinity of alpha v beta 1 for fibronectin and the failure of this integrin to localize in adhesion plaques on a fibronectin substrate. These results show that two integrins with similar ligand specificities and cell attachment functions may be quite different in their ability to support fibronectin matrix assembly and cell motility on fibronectin.

scholarly journals Multiple cell surface receptors for the short arms of laminin: alpha 1 beta 1 integrin and RGD-dependent proteins mediate cell attachment only to domains III in murine tumor laminin.

1991 ◽  
Vol 113 (4) ◽  
pp. 931-941 ◽  
Author(s):  
S L Goodman ◽  
M Aumailley ◽  
H von der Mark
Keyword(s):  
Cell Surface ◽  
Cell Attachment ◽  
Heat Denaturation ◽  
Surface Receptors ◽  
Murine Tumor ◽  
Heat Stable ◽  
Multiple Cell ◽  
Beta 1 Integrin ◽  
Mediate Cell ◽  
Alpha V Beta 3

Cell surface molecules that interact with the cross formed by the three short arms of murine tumor laminin were studied using thermal perturbation, antibody and peptide blocking, and affinity chromatography. Several potential receptors for the laminin short arms were revealed that differed from those mediating cell attachment to the E8 (long arm) fragment. Two cell lines, Rugli and L8 attached well to E1-X (short arm) fragments of laminin. This attachment was blocked by antibodies against alpha 1 integrin chains. Other cells were unable to attach strongly to E1-X, but attached to P1. This attachment was unaffected by anti-beta 1 integrin antibodies, but specifically blocked by the peptide GRGDS. By contrast, binding of Rugli cells was RGD independent and blocked by anti-beta 1 integrin antibodies. G7 and C2C12 myoblasts were very sensitive to GRGDS (ID50 approximately 2 micrograms.ml-1) for attachment to P1 which implied that a non-beta 1 series integrin, possibly alpha v beta 3, was involved. On heat denaturation of P1(3) attachment remained sensitive to RGDS and ID50 was unchanged. On heat denaturation of E1-X, attachment remained sensitive to RGDS but the ID50 increased to approximately 200 micrograms.ml-1. Cellular beta 1 integrins were retained on laminin affinity columns. A beta 1 integrin with an approximately 190 kD alpha-chain could be isolated from Rugli cells whose attachment could be blocked by anti-alpha 1 antibodies and not from cells blocked by RGDS peptides. Anti-alpha 1 antibodies blocked Rugli attachment to native laminin, but only when the E8 cell binding sites on laminin were also blocked. Thus, a receptor related to alpha 1 beta 1 integrin can function simultaneously with a receptor for E8. Anti-alpha 1 also blocked attachment to heated laminin, suggesting that the heat-stable attachment activity in laminin involved the E1-X binding site. Thus, at least two putative receptors mediate attachment to the short arms of laminin. One, related to alpha 1 beta 1 integrin, recognizes RGDS-independent sites in E1-X defined by P1 (within domains III, IIIa, IIIb), and one is an RGD-dependent molecule recognizing sites in P1, and is not a beta 1 integrin.

scholarly journals Regulation of the VLA integrin-ligand interactions through the beta 1 subunit.

1992 ◽  
Vol 117 (3) ◽  
pp. 659-670 ◽  
Author(s):  
A G Arroyo ◽  
P Sánchez-Mateos ◽  
M R Campanero ◽  
I Martín-Padura ◽  
E Dejana ◽  
...  
Keyword(s):  
Cell Attachment ◽  
Surface Membrane ◽  
Soluble Form ◽  
Membrane Expression ◽  
Ecm Proteins ◽  
Cytoplasmic Extension ◽  
Ligand Interactions ◽  
Beta 1 Integrin ◽  
The Common ◽  
Adhesive Interactions

Integrins from the very late activation antigen (VLA) subfamily are involved in cellular attachment to extracellular matrix (ECM) proteins and in intercellular adhesions. It is known that the interaction of integrin proteins with their ligands can be regulated during cellular activation. We have investigated the regulation of different VLA-mediated adhesive interactions through the common beta 1 chain. We have found that certain anti-beta 1 antibodies strongly enhance binding of myelomonocytic U-937 cells to fibronectin. This beta 1-mediated regulatory effect involved both VLA-4 and VLA-5 fibronectin receptors. Moreover, anti-beta 1 mAb also induced VLA-4-mediated binding to a recombinant soluble form of its endothelial cell ligand VCAM-1. Non-activated peripheral blood T lymphocytes, unable to mediate VLA-4 interactions with fibronectin or VCAM-1, acquired the ability to bind these ligands in the presence of anti-beta 1 mAb. The anti-beta 1-mediated changes in the affinities of beta 1 integrin for their ligands were comparable to those triggered by different lymphocyte activation agents such as anti-CD3 mAb or phorbol ester. Adhesion of melanoma cells to other ECM proteins such as laminin or collagen as well as that of alpha 2-transfected K-562 cells to collagen, was also strongly enhanced by anti-beta 1 mAb. These beta 1-mediated regulatory effects on different VLA-ligand interactions do not involve changes in cell surface membrane expression of different VLA heterodimers. The anti-beta 1-mediated functional effects required an active metabolism, cytoskeleton integrity and the existence of physiological levels of intracellular calcium as well as a functional Na+/H+ antiporter. Beta 1 antibodies not only increased cell attachment but also promoted spreading and cytoplasmic extension of endothelial cells on plates coated with either fibronectin, collagen, or laminin as well as induced the rapid appearance of microspikes in U-937 cells on fibronectin. Moreover, both beta 1 integrin and the cytoskeletal protein talin colocalized in the anti-beta 1 induced microspikes. These results emphasize the central role of the common beta 1 chain in regulating different adhesive functions mediated by VLA integrins as well as cellular morphology.

Inhibition of neural crest cell attachment by integrin antisense oligonucleotides

Science ◽  
1993 ◽  
Vol 259 (5095) ◽  
pp. 692-695 ◽  
Author(s):  
T Lallier ◽  
M Bronner-Fraser
Keyword(s):  
Extracellular Matrix ◽  
Neural Crest ◽  
Antisense Oligonucleotides ◽  
Culture Medium ◽  
Cell Attachment ◽  
Neural Crest Cell ◽  
Selective Inhibition ◽  
Extracellular Matrix Molecules ◽  
Beta 1 Integrin ◽  
Crest Cell

Neural crest cell interactions with extracellular matrix molecules were analyzed with the use of antisense oligonucleotides to block synthesis of integrin subunits. When added to the culture medium of quail neural crest cells, selected antisense phosphorothiol oligonucleotides reduced the amounts of cell surface alpha 1 or beta 1 integrin subunits by up to 95 percent and inhibited neural crest cell attachment to laminin or fibronectin substrata. Differential effects on specific alpha integrins were noted after treatment with alpha-specific oligonucleotides. Cells recovered the ability to bind to substrata 8 to 16 hours after treatment with inhibitory oligonucleotides. The operation of at least three distinct alpha integrin subunits is indicated by substratum-selective inhibition of cell attachment.

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