Identification of the minimal N-glycosylation on integrin alpha 5 beta 1 required for its inhibitory effect on EGFR signaling and cell proliferation

摘要

The N-glycosylation of integrin alpha 5 beta 1 is involved in multiple cell biological functions. Our group previously reported that the N-glycosylation of the Calf-1,2 domain on alpha 5 subunit (S3-5,10-14) was important for its inhibitory effect on EGFR signaling through regulating alpha 5-EGFR complex formation. In this followup study, we provide evidence that the N-glycosylation on integrin beta 1 subunit suppress cell growth by promoting its association with EGFR under fibronectin (FN)-coated conditions. Expression of wild-type (WT) beta 1, but not the N-glycosylation mutant S4-6 beta 1, which contains fewer N-glycans, inhibited EGFR signaling and cell proliferation after cell adhesion to FN. Furthermore, consistent restoration of the N-glycans on sites 1-3 of beta 1 reinstated the inhibitory effects. Mechanistically, the N-glycosylation mutant of 131 (S4-6+1-3) inhibited the EGFR response upon EGF stimulation via facilitating the alpha 5 beta 1-EGFR complex formation. Moreover, we identified the N-glycosylation of sites 10-14 on alpha 5 and 1-3 on beta 1 were most - important for EGFR signaling. Taken together, these data indicate that alpha 5(S3-5+10-14)beta 1(S4-6+1-3) mutant represents the minimal N-glycosylation required for its regulation on EGFR signaling and cell prolifer ation, providing a plausible mechanism for the crosstalk between with alpha 5 beta 1 and EGFR. (C) 2019 Elsevier Inc. All rights reserved.