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Geiger, Ch.* ; Nagel, W.* ; Boehm, Th.* ; Figdor, C.G.* ; Kremmer, E. ; Hogg, N.* ; Zeitlmann, L.* ; Dierks, H.* ; Weber, K.S.C.* ; Kolanus, W.*

Cytohesin-1 regulates ß-2 integrin-mediated adhesion through both ARF-GEF function and interaction with LFA-1.

EMBO J. 19, 2525-2536 (2000)
DOI
Open Access Green as soon as Postprint is submitted to ZB.
Intracellular signaling pathways, which regulate the interactions of integrins with their ligands, affect a wide variety of biological functions. Here we provide evidence of how cytohesin‐1, an integrin‐binding protein and guanine‐nucleotide exchange factor (GEF) for ARF GTPases, regulates cell adhesion. Mutational analyses of the β‐2 cytoplasmic domain revealed that the adhesive function of LFA‐1 depends on its interaction with cytohesin‐1, unless the integrin is activated by exogenous divalent cations. Secondly, cytohesin‐1 induces expression of an extracellular activation epitope of LFA‐1, and the exchange factor function is not essential for this activity. In contrast, LFA‐1‐mediated cell adhesion and spreading on intercellular cell adhesion molecule 1 is strongly inhibited by a cytohesin‐1 mutant, which fails to catalyze ARF GDP–GTP exchange in vitro. Thus, cytohesin‐1 is involved in the activation of LFA‐1, most probably through direct interaction with the integrin, and induces cell spreading by its ARF‐GEF activity. We therefore propose that both direct regulation of the integrin and concomitant changes in the membrane topology of adherent T cells are modulated by dissectable functions of cytohesin‐1.
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Publication type Article: Journal article
Document type Scientific Article
Corresponding Author
Keywords ARF GTPase cell adhesion cytohesin-1 ß-2 integrin LFA-1
ISSN (print) / ISBN 0261-4189
e-ISSN 1460-2075
Quellenangaben Volume: 19, Issue: 11, Pages: 2525-2536 Article Number: , Supplement: ,
Publisher Wiley
Publishing Place Heidelberg, Germany
Non-patent literature Publications
Reviewing status Peer reviewed