The kinase activity of the giant protein projectin of the flight muscle of Locusta migratoria.

Projectin is a member of the functionally and structurally heterogeneous family of myosin light chain kinases associated to myosin of synchronous as well as asynchronous insect muscles. We examined the phosphotransferase activity of projectin from flight muscle of Locusta migratoria. Isolated projectin exhibits an unstimulated autophosphorylation activity in vitro.