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 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 The VP5 Domain of VP4 Can Mediate Attachment of Rotaviruses to Cells

2000 ◽  
Vol 74 (2) ◽  
pp. 593-599 ◽  
Author(s):  
Selene Zárate ◽  
Rafaela Espinosa ◽  
Pedro Romero ◽  
Ernesto Méndez ◽  
Carlos F. Arias ◽  
...  
Keyword(s):  
Cell Surface ◽  
Binding Assay ◽  
Cell Attachment ◽  
Wild Type ◽  
Binding Assays ◽  
Virus Binding ◽  
Binding Characteristics ◽  
Surface Receptors ◽  
Infectivity Assay ◽  
Fusion Products

ABSTRACT Some animal rotaviruses require the presence of sialic acid (SA) on the cell surface to infect the cell. We have isolated variants of rhesus rotavirus (RRV) whose infectivity no longer depends on SA. Both the SA-dependent and -independent interactions of these viruses with the cell are mediated by the virus spike protein VP4, which is cleaved by trypsin into two domains, VP5 and VP8. In this work we have compared the binding characteristics of wild-type RRV and its variant nar3 to MA104 cells. In a direct nonradioactive binding assay, both viruses bound to the cells in a saturable and specific manner. When neutralizing monoclonal antibodies directed to both the VP8 and VP5 domains of VP4 were used to block virus binding, antibodies to VP8 blocked the cell attachment of wild-type RRV but not that of the variant nar3. Conversely, an antibody to VP5 inhibited the binding of nar3 but not that of RRV. These results suggest that while RRV binds to the cell through VP8, the variant does so through the VP5 domain of VP4. This observation was further sustained by the fact that recombinant VP8 and VP5 proteins, produced in bacteria as fusion products with glutathione S-transferase, were found to bind to MA104 cells in a specific and saturable manner and, when preincubated with the cell, were capable of inhibiting the binding of wild-type and variant viruses, respectively. In addition, the VP5 and VP8 recombinant proteins inhibited the infectivity of nar3 and RRV, respectively, confirming the results obtained in the binding assays. Interestingly, when the infectivity assay was performed on neuraminidase-treated cells, the VP5 fusion protein was also found to inhibit the infectivity of RRV, suggesting that RRV could bind to the cell through two sequential steps mediated by the interaction of VP8 and VP5 with SA-containing and SA-independent cell surface receptors, respectively.

scholarly journals Shared paramyxoviral glycoprotein architecture is adapted for diverse attachment strategies

2010 ◽  
Vol 38 (5) ◽  
pp. 1349-1355 ◽  
Author(s):  
Thomas A. Bowden ◽  
Max Crispin ◽  
E. Yvonne Jones ◽  
David I. Stuart
Keyword(s):  
Cell Surface ◽  
Viral Entry ◽  
Cell Attachment ◽  
Structural Information ◽  
Cell Receptor ◽  
Specific Protein ◽  
Cell Surface Receptors ◽  
Surface Receptors ◽  
Entry Inhibitors ◽  
Animal Pathogens

Members within the paramyxovirus subfamily Paramyxovirinae constitute a large number of highly virulent human and animal pathogens. The glycoproteins present on these viruses are responsible for mediating host cell attachment and fusion and are key targets for the design of antiviral entry inhibitors. In the present review, we discuss recent structural studies which have led to a better understanding of the various mechanisms by which different paramyxoviruses use their attachment glycoproteins to hijack specific protein and glycan cell-surface receptors to facilitate viral entry. It is observed that the paramyxovirus attachment glycoprotein consists of a conserved overall structure which includes an N-terminal six-bladed β-propeller domain which is responsible for cell receptor binding. Crystal structures of this domain from different biomedically important paramyxoviruses, including measles, Nipah, Hendra, Newcastle disease and parainfluenza viruses, alone and in complex with their functional cell-surface receptors, demonstrate three contrasting mechanisms of receptor engagement that paramyxoviruses have evolved to confer discreet protein- and glycan-receptor specificity. This structural information highlights the adaptability of the paramyxovirus attachment glycoprotein surface and the potential for the emergence of new and potentially harmful viruses in human hosts.

scholarly journals Adhesive properties of osteopontin: regulation by a naturally occurring thrombin-cleavage in close proximity to the GRGDS cell-binding domain.

1994 ◽  
Vol 5 (5) ◽  
pp. 565-574 ◽  
Author(s):  
D R Senger ◽  
C A Perruzzi ◽  
A Papadopoulos-Sergiou ◽  
L Van de Water
Keyword(s):  
Cell Surface ◽  
Cleavage Site ◽  
Cell Attachment ◽  
Binding Domain ◽  
Adhesion Assay ◽  
Cell Binding ◽  
Thrombin Cleavage ◽  
Close Proximity ◽  
Alpha V Beta 3 ◽  
Cell Binding Domain

Osteopontin (OPN) is a secreted adhesive glycoprotein with a functional glycine-arginine-glycine-aspartate-serine (GRGDS) cell-binding domain. An interesting feature of OPN structure is the presence of a thrombin-cleavage site in close proximity to the GRGDS region. Cleavage of OPN by thrombin is likely to be of physiological importance, because cleavage of blood plasma OPN occurs naturally after activation of the blood coagulation pathway. To investigate functional consequences of OPN cleavage by thrombin, cell attachment and spreading assays were performed with uncleaved and cleaved forms of OPN. For all cell lines examined, thrombin-cleaved OPN promoted markedly greater cell attachment and spreading than uncleaved OPN. Cell attachment and spreading on thrombin-cleaved OPN was inhibited both by the soluble GRGDS peptides and an OPN-specific antibody raised to the GRGDS domain of OPN, thus implicating the GRGDS region in mediating the increased cell attachment and spreading observed on thrombin-cleaved OPN. Because the GRGDS sequence in OPN is only six residues from the thrombin-cleavage site, the data suggest that possibility that thrombin cleavage allows greater accessibility of the GRGDS domain to cell surface receptors. To investigate receptors that recognize uncleaved and thrombin-cleaved OPN, affinity chromatography was performed on placental extracts; the cell surface integrin alpha v beta 3 bound to columns constructed either with native or thrombin-cleaved OPN and was selectively eluted from each with soluble GRGDS peptide and EDTA. Moreover, adhesion assays performed in the presence of alpha v beta 3 blocking monoclonal antibody LM609 identified alpha v beta 3 as a major functional receptor for thrombin-cleaved OPN. Several lines of evidence suggest that cleavage of OPN by thrombin occurs in vivo, such as in tumors and at sites of tissue injury, and adhesion assay data presented here indicate that such cleavage is important in the regulation of OPN function.

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.

scholarly journals β 1 integrins mediate adherent phenotype of human erythroblastic cell lines after phorbol 12-myristate 13-acetate induction

1995 ◽  
Vol 309 (2) ◽  
pp. 491-497 ◽  
Author(s):  
A Molla ◽  
R Berthier ◽  
A Chapel ◽  
A Schweitzer ◽  
A Andrieux
Keyword(s):  
Cell Lines ◽  
Alpha Subunit ◽  
Integrin Expression ◽  
Adherent Cells ◽  
Surface Receptors ◽  
New Synthesis ◽  
Subunit Expression ◽  
Hel Cells ◽  
Beta 1 Integrin ◽  
Alpha V Beta 3

We investigated the effects of phorbol ester (phorbol 12-myristate 13-acetate; PMA) treatment on the adhesive behaviour of three erythroleukaemia cell lines: HEL, LAMA-84 and AP217. In the three cell lines PMA induced an increase in expression of a megakaryocytic marker: alpha IIb beta 3 integrin, but did not promote activation of this receptor. Indeed, an antibody specific for the activated form of alpha IIb beta 3 failed to react with the three cell lines. PMA induction led to different adhesive phenotypes depending on the cell line; in fact LAMA-84 and HEL cells became adherent while AP217 cells remained non-adherent. By studying cell surface receptors we found that the major difference between the adherent and the non-adherent cells was the expression of beta 1 integrins. After PMA induction, beta 1 integrin expression was totally abolished in AP217 cells and the amount of beta 1 mRNA was reduced preventing new synthesis of the subunit. In HEL and LAMA-84 cells, PMA treatment did not alter the overall level of beta 1 integrin but induced a new pattern of alpha-subunit expression: up-regulation of alpha 2 and alpha v subunits and down-regulation of alpha 4 and alpha 5 subunits. Function-perturbing antibodies against beta 1, alpha 4, alpha 5, alpha v and alpha 2 reduced adhesion of HEL cells to fibronectin or collagen, whereas antibodies against beta 3 or alpha v beta 3 did not. Our results favour the involvement of beta 1 integrins in PMA-induced adhesion of erythroleukaemia cells.

scholarly journals Integrins alpha v beta 3 and alpha v beta 5 contribute to cell attachment to vitronectin but differentially distribute on the cell surface.

1991 ◽  
Vol 113 (4) ◽  
pp. 919-929 ◽  
Author(s):  
E A Wayner ◽  
R A Orlando ◽  
D A Cheresh
Keyword(s):  
Cell Surface ◽  
Lung Carcinoma ◽  
Cell Attachment ◽  
Cell Types ◽  
Carcinoma Cells ◽  
Lung Carcinoma Cells ◽  
Distinct Cell ◽  
Contact Distribution ◽  
Alpha V Beta 3

We investigated the role of the integrins alpha v beta 3 and alpha v beta 5 in mediating vitronectin adhesion of three phenotypically distinct cell types. M21 human melanoma cells and H2981 lung carcinoma cells use both alpha v-containing integrins in adhering to vitronectin while UCLA-P3 lung carcinoma cells adhere exclusively with alpha v beta 5. Specifically, monoclonal antibodies directed to functional epitopes on both receptors were required to block adhesion of M21 or H2981 cells while adhesion of UCLA-P3 cells to vitronectin could be blocked with a monoclonal antibody to alpha v beta 5. Although both receptors are involved in M21 and H2981 cell adhesion to vitronectin, only alpha v beta 3 can be detected in focal contacts, colocalizing with vinculin, talin, and the ends of actin filaments, while alpha v beta 5 shows a distinct, nonfocal contact, distribution on the cell surface. These results provide the first evidence that two homologous integrins that recognize the same ligand distribute differentially on the cell surface.

scholarly journals Expression and presence of osteopontin and integrins in the bovine oviduct during the oestrous cycle

Reproduction ◽  
2003 ◽  
pp. 721-729 ◽  
Author(s):  
C Gabler ◽  
DA Chapman ◽  
GJ Killian
Keyword(s):  
Luteal Phase ◽  
Cell Attachment ◽  
Oestrous Cycle ◽  
Functional Roles ◽  
Late Luteal Phase ◽  
Mrna Content ◽  
Mediate Cell ◽  
Alpha V Beta 3 ◽  
A Site ◽  
Oviductal Fluid

Osteopontin and integrin alpha(v)beta(3) are known to mediate cell-cell attachment and cell migration. Western blot analysis was used to demonstrate the presence of osteopontin in oviductal fluid collected from ampullar and isthmic regions. Three different osteopontin isoforms of 55 kDa, 48 kDa and 25 kDa were detected in the oviductal fluid. Each isoform was observed during the luteal and non-luteal phases and in both ampullar and isthmic fluids. The 25 kDa osteopontin was the most prevalent isoform in oviductal fluid except in isthmic fluid during the non-luteal phase of the oestrous cycle. RT-PCR was performed with RNA from oviductal cells collected from cows in the post-ovulatory, early to mid-luteal, late luteal or pre-ovulatory stages of the oestrous cycle to reveal the oviduct as a site of osteopontin and integrin synthesis. Only one osteopontin mRNA transcript was detected, and amounts did not vary throughout the oestrous cycle. In contrast, the relative expression of the integrin subtypes alpha(v) and beta(1) during the late luteal phase was lower compared with the other oestrous cycle phases. Integrin beta(3) mRNA content increased significantly from the lowest level during the late luteal phase to the highest level before ovulation. In conclusion, differential presence of osteopontin isoforms and integrins in the bovine oviduct throughout the oestrous cycle indicate that osteopontin-integrin interactions have functional roles in normal oviduct physiology which may potentially influence interactions between the gametes, the embryo, and the epithelium.

Heterobivalent Ligands Crosslink Multiple Cell-Surface Receptors — A Step Towards Personal Medicine

2009 ◽  
pp. 413-414 ◽  
Author(s):  
Jatinder S. Josan ◽  
Rajesh Sankaranarayanan ◽  
Heather L. Hand ◽  
Steve Fernandes ◽  
Liping Xu ◽  
...  
Keyword(s):  
Cell Surface ◽  
Cell Surface Receptors ◽  
Surface Receptors ◽  
Personal Medicine ◽  
Multiple Cell
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