KLC1 Regulates AKT Activation To Promote Myoblast Differentiation

Skeletal muscle is anchored by tendons to bone to affect skeletal movement.It is also involved in metabolism.Myoblast is skeletal muscle precursors which can differentiate into myotube.Therefore,myoblast plays an important role in myogenesis.Kinesin-1 is MT-based motor protein consisting of 2 motor subunits(Kinesin heavy chain,KHC)and 2 light chains(Kinesin light chain,KLC).We have previously found that KIF5B,the heavy chain of Kinesin-1,can regulate p38MAPK activation and myoblast differentiation through transporting BNIP-2.However,the role of KLC1 in myoblast differentiation remains elusive.Here,we found that the expression level of KLC1 is upregulated during myoblast differentiation and downregulated in both skeletal muscle of ageing mice and skeletal muscle of DMD mice.In addition,knockdown of KLC1 can downregulate phosphorylation of AKT and inhibit myoblast differentiation.We also found that overexpression of KLC1 can promote myoblast differentiation.Furthermore,we discovered that KLC1 interacts with IGF-1R through its N-terminus and the interaction is enhanced during myoblast differentiation.We also observed a remarkable co-localization of KLC 1 and IGF-1R.Additionally,we found that KLC1 interacts with IRS1 through its N-terminus.Taken together,our study uncovered a novel role of KLC1 in modulating IGF-1R-IRS1-AKT signaling pathway,which can help us further understand the mechanism of myoblast differentiation.