The role of phosphorylation in activation of the alpha 6A beta 1 laminin receptor.

摘要: Abstract The phorbol ester 12-myristate 13-acetate (PMA) induces phosphorylation of serine residues in the cytoplasmic domain alpha 6A integrin subunit, as well activation beta 1 laminin receptor. We examined whether correlates with induction high affinity binding by Two potential sites for protein kinase C, 1041 and 1048, are present subunit. introduced point mutations into cDNA, replacing either one or both alanine. Wild-type mutant cDNAs were transfected K562 cells. All subunit mutants expressed at levels similar to those wild-type formed heterodimers endogenous 1. Analysis state subunits resting cells after treatment PMA showed that 1041, but not is target residue PMA-induced phosphorylation. Cells expressing transfectants all bound presence, absence PMA; however, extent differed. containing alanine mutation a 2-3-fold higher than 1041. results indicate required receptor PMA, suggest that, contrast, it may reduce this ligand.