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This Article Full Text (PDF) Alert me when this article is cited Alert me if a correction is posted Services Email this article to a friend Similar articles in this journal Similar articles in PubMed Alert me to new issues of the journal Download to citation manager Rights and Permissions Citing Articles Citing Articles via CrossRef Citing Articles via Google Scholar Google Scholar Articles by Catimel, B. Articles by Leung, L. L. Search for Related Content PubMed PubMed Citation Articles by Catimel, B. Articles by Leung, L. L. Social Bookmarking                   What's this?  Previous Article  |  Table of Contents  |  Next Article  Epithelial membrane glycoprotein PAS-IV is related to platelet glycoprotein IIIb binding to thrombospondin but not to malaria-infected erythrocytes B Catimel, JL McGregor, T Hasler, DE Greenwalt, RJ Howard and LL Leung Department of Medicine, Stanford University Medical School, CA 94305- 5112. Glycoprotein (GP) IIIb (also termed GPIV or CD36) is an integral platelet membrane protein, and has been identified as a binding site for thrombospondin, collagen, and malaria-infected erythrocytes. PAS-IV is an integral membrane protein found in lactating mammary epithelial cells and capillary endothelial cells. The N-terminal sequence of PAS- IV is nearly identical to that of GPIIIb and monospecific anti-PAS-IV antibody reacts with GPIIIb, indicating that PAS-IV is structurally related to GPIIIb. In this study, human platelet GPIIIb and bovine epithelial PAS-IV were compared in terms of structural, immunologic, and functional characteristics. The two-dimensional tryptic peptide map of both intact and deglycosylated PAS-IV was highly similar but not identical to that of GPIIIb. PAS-IV and GPIIIb reacted to an equal extent with monoclonal antibodies OKM5 and OKM8 by enzyme-linked immunosorbent assay. GPIIIb bound to surface immobilized thrombospondin (TSP) in a concentration-dependent and saturable manner, with approximately 60% reduction in binding in the presence of EDTA. PAS-IV bound to TSP with similar characteristics except that maximum binding was consistently approximately 50% of that of GPIIIb and binding was not inhibited by EDTA. GPIIIb supported adhesion of Plasmodium falciparum-infected erythrocytes (PRBC) in a dose-dependent manner while no significant adhesion of PRBC to PAS-IV was observed. Our data demonstrate that while epithelial PAS-IV and platelet GPIIIb are structurally and immunologically related, there are significant differences in their functional properties. Whether this result is due to different posttranslational glycosylation modifications or that PAS- IV and GPIIIb represent a family of related cell adhesive protein receptors remains to be determined. Volume 77, Issue 12, pp. 2649-2654, 06/15/1991 Copyright © 1991 by The American Society of Hematology CiteULike    Connotea    Del.icio.us    Digg    Reddit    Technorati    What's this?

	Copyright © 1991 by American Society of Hematology         Online ISSN: 1528-0020