Membrane-induced segregation of motile and stable domains in cytoplasm: possible role in morphological differentiation of tissue cells

Many morphological differentiations and modulations involve alterations of degree of segregation in two types of cytoplasmic domains: lamellar-pseudopod-forming motile structures, actinoplasts, and non-motile cylindrical processes, tubuloplasts. Pronounced reversible segregation of actinoplasts and tubuloplasts can be induced in certain fibroblastic cells by phorbol ester. Analysis of this model reorganization suggests that formation of tubuloplasts from actinoplasts may involve local collapse of actin network and microtubule-directed translocation of actin material from collapsing zone; these cytoskeletal alterations may be controlled by membrane-activated regulatory enzymes.