Tyrosine phosphorylation of myosin heavy chain during skeletal muscle differentiation: an integrated bioinformatics approach.

D F Harney,R J Edwards,R K Butler

doi:10.1186/1742-4682-2-12

Abstract

BackgroundPreviously it has been shown that insulin-mediated tyrosine phosphorylation of myosin heavy chain is concomitant with enhanced association of C-terminal SRC kinase during skeletal muscle differentiation. We sought to identify putative site(s) for this phosphorylation event.ResultsA combined bioinformatics approach of motif prediction and evolutionary and structural analyses identified tyrosines163 and 1856 of the skeletal muscle heavy chain as the leading candidate for the sites of insulin-mediated tyrosine phosphorylation.ConclusionOur work is suggestive that tyrosine phosphorylation of myosin heavy chain, whether in skeletal muscle or in platelets, is a significant event that may initiate cytoskeletal reorganization of muscle cells and platelets. Our studies provide a good starting point for further functional analysis of MHC phosphor-signalling events within different cells.

Highlights

Myosins, actin-based motor proteins, are expressed as multiple isoforms in all eukaryotic cells
Twenty-three myosin heavy chain sequences were used for tyrosine phosphorylation motif prediction, which were divided into five groups of orthologous sequences (Figure 1)
Six were predicted by both methods, including two motifs that were conserved across all sequences (MYH1_HUMAN Y163 and Y1856)

Summary

Introduction

Actin-based motor proteins, are expressed as multiple isoforms in all eukaryotic cells They are oligomers consisting of one or two heavy chains to which one or more light chains are non-covalently attached. The claims of tyrosine phosphorylation of MHC in vivo remain somewhat controversial, tyrosine phosphorylation of non-muscle MHC IIa has been implicated as an early event in human platelet activation [5]. To settle this controversy and establish the role, if any, of MHC tyrosine phosphorylation it is important to identify sites at which such phosphorylation events may occur. We sought to identify putative site(s) for this phosphorylation event

Methods

Results

Conclusion