TGFBR2 mediated phosphorylation of BUB1 at Ser-318 is required for transforming growth factor-β signaling.

ABSTRACT: BUB1 (budding uninhibited by benzimidazoles-1) is required for efficient TGF-β signaling, through its role in stabilizing the TGFBR1 and TGFBR2 complex. Here we demonstrate that TGFBR2 phosphorylates BUB1 at Serine-318, which is conserved in primates. S318 phosphorylation abrogates the interaction of BUB1 with TGFBR1 and SMAD2. Using BUB1 truncation domains (1-241, 241-482 and 482-723), we demonstrate that multiple contact points exist between BUB1 and TGF-β signaling components and that these interactions are independent of the BUB1 tetratricopeptide repeat (TPR) domain. Moreover, substitutions in the middle domain (241-482) encompassing S318 reveals that efficient interaction with TGFBR2 occurs only in its dephosphorylated state (241-482 S318A). In contrast, the phospho-mimicking mutant

SUBMITTER: Nyati S 

PROVIDER: S-EPMC7057164 | biostudies-literature | 2020 Apr

REPOSITORIES: biostudies-literature