Actin in the green algae Coleochaete and Mougeotia

Abstract
Filaments associated with chloroplasts in cytoplasmic homogenates of the algae Coleochaete scutata and Mougeotia sp. bind rabbit skeletal muscle heavy meromyosin (HMM) to form arrowhead complexes that could be dissociated with ATP. This result suggests that the filaments are actin which may be involved in the characteristic chloroplast movements exhibited by these algae.