[Effect of the Integrin ß3 Cytoplasmic NITY Motif on α II bß3-Mediated Cell Functions in CHO Cell Model].

ABSTRACT

UNLABELLED OBJLECTIVE To investigate the effect of integrin ß3 cytoplasmic NITY motif on αIIbß3-mediated cell functions. METHODS: Stable Chinese hamster ovary (CHO) cell lines that co-express human wild type integrin αIIb and wild type ß3 or mutant ß3ΔNITY (ß3 deleting cytoplasmic NITY motif) were established. Expression of αIIb and ß3 were tested by Western blot and flow cytometry in CHO cell lines. Spreading and adhesion of stable cell lines on immobilized fibrinogen were examined. The co-immunoprecipitation was used to detect protein interactions. RESULTS: CHO-αIIbß3, CHO-αIIbß3ΔNITY cells were successfully established. The CHO cells transfected with wild type αIIbß3 had the ability of adhesion and spreading. Compared with CHO-αIIbß3 cells, CHO-αIIbß3ΔNITY cells showed an impaired capacity of adhesion but no significant difference was observed in spreading of adhered cells. The co-immunoprecipitation showed that kindlin-2 associated with wild type integrin αIIbß3. The ß3ΔNITY mutation substantially reduced kindlin-2 association. CONCLUSION: Deletion of NITY motif causes an impaired ability of adhesion. The deletion mutation can suppress kindlin-2 binding to integrin ß3, thereby partially inhibit the integrin ß3 signaling.