Proteomic Analysis of Myogenesis Defining the Cytoskeletome

Abstract

Our lab uses the C2C12 myoblastic cell line in studies of muscle development, or myogenesis. Recent studies investigated the role of the large muscle protein titin, and the small carbohydrate-binding protein galectin in myogenesis. Myogenesis requires the concerted action of a vast array of various proteins as myoblasts enter differentiation and fuse into functional muscle fibers. Our lab has hitherto lacked a full description of the proteomic changes that occur in C2C12 cells as they transit the myogenic process, especially changes that inevitably occur in the cytoskeleton and extracellular matrix as individual myoblasts fuse into extended myofibers. This data indicates that the relative expression levels of some of the more prominent proteins change drastically during this process, by comparing densitometry data from cellular lysate samples extracted from cell lines at regular intervals from differentiating myoblasts. The investigation also demonstrates the possibility post-translational modifications occurring in various low molecular weight proteins made apparent by gradual electrophoretic mobility shifts of specific bands throughout the time course. This investigation allows this laboratory's studies to proceed into more detailed investigations of myogenesis, particularly morphological and proteomic changes that occur when C2C12 myoblasts are cultured upon fascia tissue. One dimensional electrophoretic analysis is insufficient to fully account for the complete changes that occur in the proteome of C2C12 myoblasts. Therefore, future work should include two dimensional SDS-PAGE to gain a better appreciation for the changes that occur in a proteome.