Lysed chromatophores: a model system for the study of bidirectional organelle transport.

The development of procedures to lyse and reactivate pigment granule movements in chromatophores has provided the only information to date concerning the mechanisms by which cells regulate the direction of organelle transport. Continued analysis of motility in these models as well as in a reconstituted system containing only the pigment granules, the appropriate cytoskeletal structures, and defined soluble cell components should contribute to our understanding of the mechanisms by which protein phosphorylation and dephosphorylation or Ca2+ regulate direction of transport and to the identification and characterization of the force-generating proteins responsible for producing bidirectional organelle movements.