Spectrin is a ubiquitous heterodimeric scaffolding protein that stabilizes membranes and
organizes protein and lipid microdomains on both the plasma membrane and intracellular
organelles. Phosphorylation of β-spectrin on Ser/Thr is well recognized. Less clear is
whether α-spectrin is phosphorylatedin vivo and whether spectrin is phosphorylated on
tyrosine (pTyr). We affirmatively answer both questions. In cultured Madin-Darby canine
kidney cells, αII spectrin undergoesin vivo tyrosine phosphorylation. Enhancement of the …