title: Short form of α9 promotes α9β1 integrin-dependent cell adhesion by modulating the function of the full-length α9 subunit.
abstract: The α9β1 integrin is a multifunctional receptor that interacts with a variety of ligands including vascular cell adhesion molecule 1, tenascin-C, and osteopontin. A 2.3-kb truncated form of α9 integrin subunit cDNA was identified by searching the Medline database. This splice variant, which we called the short form of α9 integrin (SFα9), encodes a 632-aa isoform lacking transmembrane and cytoplasmic domains, and its authentic expression was verified by PCR and Western blotting. SFα9 is expressed on the cell surface but cannot bind ligand in the absence of the full-length α9 subunit. Over-expression of SFα9 in cells expressing full-length α9 promotes α9-dependent cell adhesion. This promoting effect of SFα9 requires the authentic cytoplasmic domain of the co-expressed full-length α9 subunit. Thus, SFα9 is a novel functional modulator of α9β1 integrin by inside-out signaling.
authors.affiliation: Lung Biology Center, Department of Medicine, University of California, San Francisco, CA 94143, USA.
authors.forename: Shigeyuki
authors.initials: S
authors.lastname: Kon
authors.forename: Amha
authors.initials: A
authors.lastname: Atakilit
authors.forename: Dean
authors.initials: D
authors.lastname: Sheppard
mesh_terms: D017398:Alternative Splicing; D000818:Animals; D015153:Blotting, Western; D016466:CHO Cells; D002448:Cell Adhesion; D002465:Cell Movement; D002478:Cells, Cultured; D006224:Cricetinae; D003412:Cricetulus; D005434:Flow Cytometry; D006801:Humans; D039001:Integrin alpha Chains / Q000235:genetics* / Q000378:metabolism; D016023:Integrins / Q000235:genetics* / Q000378:metabolism; D011485:Protein Binding; D012333:RNA, Messenger / Q000235:genetics; D020133:Reverse Transcriptase Polymerase Chain Reaction; D015398:Signal Transduction; D019063:Tenascin / Q000235:genetics* / Q000378:metabolism
chemical_list: D039001:Integrin alpha Chains; D016023:Integrins; D012333:RNA, Messenger; D019063:Tenascin; C113256:integrin alpha 9 beta 1; C084613:integrin alpha9