Identification and characterization of Drosophila homolog of Rho-kinase.
The Rho family of small GTPases and their associated regulators and targets are essential mediators of diverse morphogenetic events in development. Mammalian Rho-kinase/ROK alpha, one of the targets of Rho, has been shown to bind to Rho in GTP-bound form and to phosphorylate the myosin light chain (MLC) and the myosin-binding subunit (MBS) of myosin phosphatase, resulting in the activation of myosin. Thus, Rho-kinase/ROK alpha has been suggested to play essential roles in the formation of stress fibers and focal adhesions. We have identified the Drosophila homolog of Rho-kinase/ROK alpha, DRho-kinase, which has conserved the basic structural feature of Rho-kinase/ROK alpha consisting of the N-terminal kinase, central coiled-coil and C-terminal pleckstrin homology (PH) domains. A two-hybrid analysis demonstrated that DRho-kinase interacts with the GTP-bound form of the Drosophila Rho. Drho1, at the conserved Rho-binding site. DRho-kinase can phosphorylate MLC and MBS, preferable substrates for bovine Rho-kinase, in vitro. DRho-kinase is ubiquitously expressed throughout development, in a pattern essentially identical to that of Drho1. These results suggest that DRho-kinase is an effector of Drho1.
Mizuno
T
T
Division of Biological Science, Graduate School of Science, Nagoya University, Japan.
Amano
M
M
Kaibuchi
K
K
Nishida
Y
Y
D000595:Amino Acid Sequence; D000818:Animals; D003001:Cloning, Molecular; D018076:DNA, Complementary; D004330:Drosophila / Q000201:enzymology*; D006801:Humans; D047908:Intracellular Signaling Peptides and Proteins; D008969:Molecular Sequence Data; D011485:Protein Binding; D017346:Protein Serine-Threonine Kinases / Q000737:chemistry* / Q000235:genetics / Q000378:metabolism; D017386:Sequence Homology, Amino Acid; D054460:rho-Associated Kinases
D018076:DNA, Complementary; D047908:Intracellular Signaling Peptides and Proteins; D017346:Protein Serine-Threonine Kinases; D054460:rho-Associated Kinases