Myocyte stress 1 (MS1) is a recently described striated muscle actin-binding protein that is up-regulated in the early stages of pressure overload left ventricular hypertrophy. The aim of this study was to determine whether MS1 induces cellular hypertrophy and protects against apoptosis. Over-expressed MS1 co-localized with actin in H9c2 cells and altered expression of genes of the myocardin-related transcription factor (MRTF)/serum response factor (SRF) transcriptional pathways and in addition the apoptosis repressor with caspase recruitment domain (Nol3) gene. The size of cells over-expressing MS1 was significantly increased by 55% and over-expression of MS1 dramatically inhibited staurosporine-induced apoptosis by 89%. These findings suggest the involvement of MS1 in cellular hypertrophy and protection against apoptosis.