The unique cytoplasmic domain of human FcγRIIIA regulates receptor-mediated function.

ABSTRACT: Ligand specificity characterizes receptors for Abs and many other immune receptors, but the common use of the FcR γ-chain as their signaling subunit challenges the concept that these receptors are functionally distinct. We hypothesized that elements for specificity might be determined by the unique cytoplasmic domain (CY) sequences of the ligand-binding α-chains of γ-chain-associated receptors. Among Fcγ receptors, a protein kinase C (PKC) phosphorylation consensus motif [RSSTR], identified within the FcγRIIIa (CD16A) CY by in silico analysis, is specifically phosphorylated by PKCs, unlike other FcRs. Phosphorylated CD16A mediates a more robust calcium flux, tyrosine phosphorylation of Syk, and proinflammatory cytokine production, whereas nonphosphorylatable CD16A is more effective at acti

SUBMITTER: Li X 

PROVIDER: S-EPMC3478424 | biostudies-literature | 2012 Nov

REPOSITORIES: biostudies-literature