UNLABELLEDOBJLECTIVE: To investigate the effect of integrin β3 cytoplasmic NITY motif on αIIbβ3-mediated cell functions.

METHODSStable Chinese hamster ovary (CHO) cell lines that co-express human wild type integrin αIIb and wild type β3 or mutant β3ΔNITY (β3 deleting cytoplasmic NITY motif) were established. Expression of αIIb and β3 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.

RESULTSCHO-αIIbβ3, CHO-αIIbβ3ΔNITY cells were successfully established. The CHO cells transfected with wild type αIIbβ3 had the ability of adhesion and spreading. Compared with CHO-αIIbβ3 cells, CHO-αIIbβ3ΔNITY 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 αIIbβ3. The β3ΔNITY mutation substantially reduced kindlin-2 association.

CONCLUSIONDeletion of NITY motif causes an impaired ability of adhesion. The deletion mutation can suppress kindlin-2 binding to integrin β3, thereby partially inhibit the integrin β3 signaling.