Is an ortholog of human MYH4 (myosin heavy chain 4)\; MYH6 (myosin heavy chain 6)\; and MYH7 (myosin heavy chain 7). Exhibits actin filament binding activity and microfilament motor activity. Is involved in several processes, including inositol lipid-mediated signaling\; locomotion\; and muscle contraction. Localizes to the A band and striated muscle myosin thick filament. Is expressed in the anal depressor muscle\; the body wall musculature\; the head\; the vulval muscle\; and in the male. Human ortholog(s) of this gene are implicated in several diseases, including Carney complex\; intrinsic cardiomyopathy (multiple)\; and muscle tissue disease (multiple).