Expression and Partial Characterization of Kinesin-related Proteins in Differentiating and Adult Skeletal Muscle

Abstract

Using pan-kinesin antibodies to screen a differentiating C2C12 cell library, we identified the kinesin proteins KIF3A, KIF3B, and conventional kinesin heavy chain to be present in differentiating skeletal muscle. We compared the expression and subcellular localization characteristics of these kinesins in myogenic cells to others previously identified in muscle, neuronal, and mitotic systems (KIF1C, KIF3C, and mitotic-centromere-associated kinesin). Because members of the KIF3 subfamily of kinesin-related proteins showed altered subcellular fractionation characteristics in differentiating cells, we focused our study of kinesins in muscle on the function of kinesin-II. Kinesin-II is a motor complex comprised of dimerized KIF3A and KIF3B proteins and a tail-associated protein, KAP. The Xenopus homologue of KIF3B, Xklp3, is predominantly localized to the region of the Golgi apparatus, and overexpression of motorless-Xklp3 in Xenopus A6 cells causes mislocalization of Golgi components (). In C2C12 myoblasts and myotubes, KIF3B is diffuse and punctate, and not primarily associated with the Golgi. Overexpression of motorless-KIF3B does not perturb localization of Golgi components in myogenic cells, and myofibrillogenesis is normal. In adult skeletal muscle, KIF3B colocalizes with the excitation-contraction-coupling membranes. We propose that these membranes, consisting of the transverse-tubules and sarcoplasmic reticulum, are dynamic structures in which kinesin-II may function to actively assemble and maintain in myogenic cells.

Oxidative stress decreases microtubule growth and stability in ventricular myocytes

“…Kif2c has only been reported to be associated with dividing cells and has never been found in terminally differentiated cardiac tissue. Furthermore, Kif2C expression is lost from postmitotic C2C12 cells as they undergo myofibrillogenesis [56]. Thus, we conclude that the increase seen in Kif2c transcript after MI is likely due to fibroblasts and other dividing cells migrating into the infarcted region rather than novel expression of this molecular inducer of catastrophe in ventricular myocytes.…”

Preliminary quantitative profile of differential protein expression between rat L6 myoblasts and myotubes by stable isotope labeling with amino acids in cell culture

“…Dynamin-2, a microtubule-associated force-producing protein involved in producing microtubule bundles and vesicular trafficking processes [39], may be also associated with myoblasts fusion. Kinesin-1, a microtubule-dependent motor required for normal distribution of cellular components, was up-regulated by 4.4 fold, which indicates that myotube is a critical dynamic cellular component in myoblast differentiation [40]. Besides microtubules, intermediate filament is another important family of cytoskeletal proteins associated with myotubes transformation.…”

Direct Functional Interaction of the Kinesin-13 Family Membrane Kinesin-like Protein 2A (Kif2A) and Arf GAP with GTP-binding Protein-like, Ankyrin Repeats and PH Domains1 (AGAP1)

“…It binds the end of the microtubules where ATP hydrolysis drives the removal of tubulin dimers (16). Unlike Kif2C (17), Kif2A is expressed in terminally differentiated cells including neurons (18) and cardiomyocytes (19). A limited number of studies have examined kinesin-13s in interphase cells.…”