A novel role of PRR14 in the regulation of skeletal myogenesis.

Dysregulation of genes involved in organizing and maintaining nuclear structures, such as SYNE1, SYNE2, TREM43, EMD and LMNA is frequently associated with diverse diseases termed laminopathies, which often affect the muscle tissue. The PRR14 protein was recently reported to tether heterochromatin to nuclear lamina but its function remains largely unknown. Here, we present several lines of evidence demonstrating a critical role of PRR14 in regulation of myoblast differentiation. We found that Prr14 expression was upregulated during skeletal myogenesis. Knockdown of Prr14 impeded, whereas overexpression of PRR14 enhanced C2C12 differentiation. The pro-myogenesis activity of PRR14 seemed to correlate with its ability to support cell survival and to maintain the stability and structure of lamin A/C. In addition, PRR14 stimulated the activity of MyoD via binding to heterochromatin protein 1 alpha (HP1α). The results altogether support a model in which PRR14 promotes skeletal myogenesis via supporting nuclear lamina structure and enhancing the activity of MyoD.