Cookies on this website

We use cookies to ensure that we give you the best experience on our website. If you click 'Accept all cookies' we'll assume that you are happy to receive all cookies and you won't see this message again. If you click 'Reject all non-essential cookies' only necessary cookies providing core functionality such as security, network management, and accessibility will be enabled. Click 'Find out more' for information on how to change your cookie settings.

Centrosomes are the main microtubule (MT)-organizing centers in animal cells, but they also influence the actin/myosin cytoskeleton. The Drosophila CP190 protein is nuclear in interphase, interacts with centrosomes during mitosis, and binds to MTs directly in vitro. CP190 has an essential function in the nucleus as a chromatin insulator, but centrosomes and MTs appear unperturbed in Cp190 mutants. Thus, the centrosomal function of CP190, if any, is unclear. Here, we examine the function of CP190 in Cp190 mutant germline clone embryos. Mitosis is not perturbed in these embryos, but they fail in axial expansion, an actin/myosin-dependent process that distributes the nuclei along the anterior-to-posterior axis of the embryo. Myosin organization is disrupted in these embryos, but actin appears unaffected. Moreover, a constitutively activated form of the myosin regulatory light chain can rescue the axial expansion defect in mutant embryos, suggesting that CP190 acts upstream of myosin activation. A CP190 mutant that cannot bind to MTs or centrosomes can rescue the lethality associated with Cp190 mutations, presumably because it retains its nuclear functions, but it cannot rescue the defects in myosin organization in embryos. Thus, CP190 has distinct nuclear and centrosomal functions, and it provides a crucial link between the centrosome/MT and actin/myosin cytoskeletal systems in early embryos.

Original publication




Journal article


Curr Biol

Publication Date





1308 - 1313


Animals, Centrosome, Drosophila, Drosophila Proteins, Embryo, Nonmammalian, Fluorescent Antibody Technique, Microscopy, Confocal, Microtubule-Associated Proteins, Mitosis, Mutation, Myosins, Nuclear Proteins