Abstract
A dynamic actomyosin cytoskeleton drives many morphogenetic events. Conventional nonmuscle myosin-II (myosin) is a key chemomechanical motor that drives contraction of the actin cytoskeleton. We have explored the regulation of myosin activity by performing genetic screens to identify gene products that collaborate with myosin during Drosophila morphogenesis. Specifically, we screened for second-site noncomplementors of a mutation in the zipper gene that encodes the nonmuscle myosin-II heavy chain. We determined that a single missense mutation in the zipper(Ebr) allele gives rise to its sensitivity to second-site noncomplementation. We then identify the Rho signal transduction pathway as necessary for proper myosin function. First we show that a lethal P-element insertion interacts genetically with zipper. Subsequently we show that this second-site noncomplementing mutation disrupts the RhoGEF2 locus. Next, we show that two EMS-induced mutations, previously shown to interact genetically with zipper(Ebr), disrupt the RhoA locus. Further, we have identified their molecular lesions and determined that disruption of the carboxyl-terminal CaaX box gives rise to their mutant phenotype. Finally, we show that RhoA mutations themselves can be utilized in genetic screens. Biochemical and cell culture analyses suggest that Rho signal transduction regulates the activity of myosin. Our studies provide direct genetic proof of the biological relevance of regulation of myosin by Rho signal transduction in an intact metazoan.
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- Amano M., Ito M., Kimura K., Fukata Y., Chihara K., Nakano T., Matsuura Y., Kaibuchi K. Phosphorylation and activation of myosin by Rho-associated kinase (Rho-kinase). J Biol Chem. 1996 Aug 23;271(34):20246–20249. doi: 10.1074/jbc.271.34.20246. [DOI] [PubMed] [Google Scholar]
- Barrett K., Leptin M., Settleman J. The Rho GTPase and a putative RhoGEF mediate a signaling pathway for the cell shape changes in Drosophila gastrulation. Cell. 1997 Dec 26;91(7):905–915. doi: 10.1016/s0092-8674(00)80482-1. [DOI] [PubMed] [Google Scholar]
- Bi E., Maddox P., Lew D. J., Salmon E. D., McMillan J. N., Yeh E., Pringle J. R. Involvement of an actomyosin contractile ring in Saccharomyces cerevisiae cytokinesis. J Cell Biol. 1998 Sep 7;142(5):1301–1312. doi: 10.1083/jcb.142.5.1301. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Blake K. J., Myette G., Jack J. The products of ribbon and raw are necessary for proper cell shape and cellular localization of nonmuscle myosin in Drosophila. Dev Biol. 1998 Nov 1;203(1):177–188. doi: 10.1006/dbio.1998.9036. [DOI] [PubMed] [Google Scholar]
- Byers T. J., Dubreuil R., Branton D., Kiehart D. P., Goldstein L. S. Drosophila spectrin. II. Conserved features of the alpha-subunit are revealed by analysis of cDNA clones and fusion proteins. J Cell Biol. 1987 Nov;105(5):2103–2110. doi: 10.1083/jcb.105.5.2103. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Chrzanowska-Wodnicka M., Burridge K. Rho-stimulated contractility drives the formation of stress fibers and focal adhesions. J Cell Biol. 1996 Jun;133(6):1403–1415. doi: 10.1083/jcb.133.6.1403. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Condic M. L., Fristrom D., Fristrom J. W. Apical cell shape changes during Drosophila imaginal leg disc elongation: a novel morphogenetic mechanism. Development. 1991 Jan;111(1):23–33. doi: 10.1242/dev.111.1.23. [DOI] [PubMed] [Google Scholar]
- Crawford J. M., Harden N., Leung T., Lim L., Kiehart D. P. Cellularization in Drosophila melanogaster is disrupted by the inhibition of rho activity and the activation of Cdc42 function. Dev Biol. 1998 Dec 1;204(1):151–164. doi: 10.1006/dbio.1998.9061. [DOI] [PubMed] [Google Scholar]
- Côté S., Preiss A., Haller J., Schuh R., Kienlin A., Seifert E., Jäckle H. The gooseberry-zipper region of Drosophila: five genes encode different spatially restricted transcripts in the embryo. EMBO J. 1987 Sep;6(9):2793–2801. doi: 10.1002/j.1460-2075.1987.tb02575.x. [DOI] [PMC free article] [PubMed] [Google Scholar]
- De Lozanne A., Spudich J. A. Disruption of the Dictyostelium myosin heavy chain gene by homologous recombination. Science. 1987 May 29;236(4805):1086–1091. doi: 10.1126/science.3576222. [DOI] [PubMed] [Google Scholar]
- Edwards K. A., Kiehart D. P. Drosophila nonmuscle myosin II has multiple essential roles in imaginal disc and egg chamber morphogenesis. Development. 1996 May;122(5):1499–1511. doi: 10.1242/dev.122.5.1499. [DOI] [PubMed] [Google Scholar]
- Gibson F., Walsh J., Mburu P., Varela A., Brown K. A., Antonio M., Beisel K. W., Steel K. P., Brown S. D. A type VII myosin encoded by the mouse deafness gene shaker-1. Nature. 1995 Mar 2;374(6517):62–64. doi: 10.1038/374062a0. [DOI] [PubMed] [Google Scholar]
- Gloor G. B., Preston C. R., Johnson-Schlitz D. M., Nassif N. A., Phillis R. W., Benz W. K., Robertson H. M., Engels W. R. Type I repressors of P element mobility. Genetics. 1993 Sep;135(1):81–95. doi: 10.1093/genetics/135.1.81. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Gotwals P. J., Fristrom J. W. Three neighboring genes interact with the Broad-Complex and the Stubble-stubbloid locus to affect imaginal disc morphogenesis in Drosophila. Genetics. 1991 Apr;127(4):747–759. doi: 10.1093/genetics/127.4.747. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Halsell S. R., Kiehart D. P. Second-site noncomplementation identifies genomic regions required for Drosophila nonmuscle myosin function during morphogenesis. Genetics. 1998 Apr;148(4):1845–1863. doi: 10.1093/genetics/148.4.1845. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Harden N., Loh H. Y., Chia W., Lim L. A dominant inhibitory version of the small GTP-binding protein Rac disrupts cytoskeletal structures and inhibits developmental cell shape changes in Drosophila. Development. 1995 Mar;121(3):903–914. doi: 10.1242/dev.121.3.903. [DOI] [PubMed] [Google Scholar]
- Harden N., Ricos M., Ong Y. M., Chia W., Lim L. Participation of small GTPases in dorsal closure of the Drosophila embryo: distinct roles for Rho subfamily proteins in epithelial morphogenesis. J Cell Sci. 1999 Feb;112(Pt 3):273–284. doi: 10.1242/jcs.112.3.273. [DOI] [PubMed] [Google Scholar]
- Hariharan I. K., Hu K. Q., Asha H., Quintanilla A., Ezzell R. M., Settleman J. Characterization of rho GTPase family homologues in Drosophila melanogaster: overexpressing Rho1 in retinal cells causes a late developmental defect. EMBO J. 1995 Jan 16;14(2):292–302. doi: 10.1002/j.1460-2075.1995.tb07003.x. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Häcker U., Perrimon N. DRhoGEF2 encodes a member of the Dbl family of oncogenes and controls cell shape changes during gastrulation in Drosophila. Genes Dev. 1998 Jan 15;12(2):274–284. doi: 10.1101/gad.12.2.274. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Ishizaki T., Maekawa M., Fujisawa K., Okawa K., Iwamatsu A., Fujita A., Watanabe N., Saito Y., Kakizuka A., Morii N. The small GTP-binding protein Rho binds to and activates a 160 kDa Ser/Thr protein kinase homologous to myotonic dystrophy kinase. EMBO J. 1996 Apr 15;15(8):1885–1893. [PMC free article] [PubMed] [Google Scholar]
- Janecke A. R., Meins M., Sadeghi M., Grundmann K., Apfelstedt-Sylla E., Zrenner E., Rosenberg T., Gal A. Twelve novel myosin VIIA mutations in 34 patients with Usher syndrome type I: confirmation of genetic heterogeneity. Hum Mutat. 1999;13(2):133–140. doi: 10.1002/(SICI)1098-1004(1999)13:2<133::AID-HUMU5>3.0.CO;2-U. [DOI] [PubMed] [Google Scholar]
- Jordan P., Karess R. Myosin light chain-activating phosphorylation sites are required for oogenesis in Drosophila. J Cell Biol. 1997 Dec 29;139(7):1805–1819. doi: 10.1083/jcb.139.7.1805. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Karess R. E., Chang X. J., Edwards K. A., Kulkarni S., Aguilera I., Kiehart D. P. The regulatory light chain of nonmuscle myosin is encoded by spaghetti-squash, a gene required for cytokinesis in Drosophila. Cell. 1991 Jun 28;65(7):1177–1189. doi: 10.1016/0092-8674(91)90013-o. [DOI] [PubMed] [Google Scholar]
- Ketchum A. S., Stewart C. T., Stewart M., Kiehart D. P. Complete sequence of the Drosophila nonmuscle myosin heavy-chain transcript: conserved sequences in the myosin tail and differential splicing in the 5' untranslated sequence. Proc Natl Acad Sci U S A. 1990 Aug;87(16):6316–6320. doi: 10.1073/pnas.87.16.6316. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Kiehart D. P., Feghali R. Cytoplasmic myosin from Drosophila melanogaster. J Cell Biol. 1986 Oct;103(4):1517–1525. doi: 10.1083/jcb.103.4.1517. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Kiehart D. P., Galbraith C. G., Edwards K. A., Rickoll W. L., Montague R. A. Multiple forces contribute to cell sheet morphogenesis for dorsal closure in Drosophila. J Cell Biol. 2000 Apr 17;149(2):471–490. doi: 10.1083/jcb.149.2.471. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Kiehart D. P., Montague R. A., Rickoll W. L., Foard D., Thomas G. H. High-resolution microscopic methods for the analysis of cellular movements in Drosophila embryos. Methods Cell Biol. 1994;44:507–532. doi: 10.1016/s0091-679x(08)60929-2. [DOI] [PubMed] [Google Scholar]
- Kimura K., Ito M., Amano M., Chihara K., Fukata Y., Nakafuku M., Yamamori B., Feng J., Nakano T., Okawa K. Regulation of myosin phosphatase by Rho and Rho-associated kinase (Rho-kinase) Science. 1996 Jul 12;273(5272):245–248. doi: 10.1126/science.273.5272.245. [DOI] [PubMed] [Google Scholar]
- Knecht D. A., Loomis W. F. Antisense RNA inactivation of myosin heavy chain gene expression in Dictyostelium discoideum. Science. 1987 May 29;236(4805):1081–1086. doi: 10.1126/science.3576221. [DOI] [PubMed] [Google Scholar]
- Knecht D. A., Shelden E. Three-dimensional localization of wild-type and myosin II mutant cells during morphogenesis of Dictyostelium. Dev Biol. 1995 Aug;170(2):434–444. doi: 10.1006/dbio.1995.1227. [DOI] [PubMed] [Google Scholar]
- Leptin M., Casal J., Grunewald B., Reuter R. Mechanisms of early Drosophila mesoderm formation. Dev Suppl. 1992:23–31. [PubMed] [Google Scholar]
- Leung T., Manser E., Tan L., Lim L. A novel serine/threonine kinase binding the Ras-related RhoA GTPase which translocates the kinase to peripheral membranes. J Biol Chem. 1995 Dec 8;270(49):29051–29054. doi: 10.1074/jbc.270.49.29051. [DOI] [PubMed] [Google Scholar]
- Magie C. R., Meyer M. R., Gorsuch M. S., Parkhurst S. M. Mutations in the Rho1 small GTPase disrupt morphogenesis and segmentation during early Drosophila development. Development. 1999 Dec;126(23):5353–5364. doi: 10.1242/dev.126.23.5353. [DOI] [PubMed] [Google Scholar]
- Mansfield S. G., al-Shirawi D. Y., Ketchum A. S., Newbern E. C., Kiehart D. P. Molecular organization and alternative splicing in zipper, the gene that encodes the Drosophila non-muscle myosin II heavy chain. J Mol Biol. 1996 Jan 12;255(1):98–109. doi: 10.1006/jmbi.1996.0009. [DOI] [PubMed] [Google Scholar]
- Manstein D. J., Titus M. A., De Lozanne A., Spudich J. A. Gene replacement in Dictyostelium: generation of myosin null mutants. EMBO J. 1989 Mar;8(3):923–932. doi: 10.1002/j.1460-2075.1989.tb03453.x. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Matsui T., Amano M., Yamamoto T., Chihara K., Nakafuku M., Ito M., Nakano T., Okawa K., Iwamatsu A., Kaibuchi K. Rho-associated kinase, a novel serine/threonine kinase, as a putative target for small GTP binding protein Rho. EMBO J. 1996 May 1;15(9):2208–2216. [PMC free article] [PubMed] [Google Scholar]
- Murphy A. M., Montell D. J. Cell type-specific roles for Cdc42, Rac, and RhoL in Drosophila oogenesis. J Cell Biol. 1996 May;133(3):617–630. doi: 10.1083/jcb.133.3.617. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Neujahr R., Heizer C., Gerisch G. Myosin II-independent processes in mitotic cells of Dictyostelium discoideum: redistribution of the nuclei, re-arrangement of the actin system and formation of the cleavage furrow. J Cell Sci. 1997 Jan;110(Pt 2):123–137. doi: 10.1242/jcs.110.2.123. [DOI] [PubMed] [Google Scholar]
- Noselli S. JNK signaling and morphogenesis in Drosophila. Trends Genet. 1998 Jan;14(1):33–38. doi: 10.1016/S0168-9525(97)01320-6. [DOI] [PubMed] [Google Scholar]
- Pederson J. D., Kiehart D. P., Mahaffey J. W. The role of HOM-C genes in segmental transformations: reexamination of the Drosophila Sex combs reduced embryonic phenotype. Dev Biol. 1996 Nov 25;180(1):131–142. doi: 10.1006/dbio.1996.0290. [DOI] [PubMed] [Google Scholar]
- Perrimon N., Lanjuin A., Arnold C., Noll E. Zygotic lethal mutations with maternal effect phenotypes in Drosophila melanogaster. II. Loci on the second and third chromosomes identified by P-element-induced mutations. Genetics. 1996 Dec;144(4):1681–1692. doi: 10.1093/genetics/144.4.1681. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Priess J. R., Hirsh D. I. Caenorhabditis elegans morphogenesis: the role of the cytoskeleton in elongation of the embryo. Dev Biol. 1986 Sep;117(1):156–173. doi: 10.1016/0012-1606(86)90358-1. [DOI] [PubMed] [Google Scholar]
- Rayment I., Rypniewski W. R., Schmidt-Bäse K., Smith R., Tomchick D. R., Benning M. M., Winkelmann D. A., Wesenberg G., Holden H. M. Three-dimensional structure of myosin subfragment-1: a molecular motor. Science. 1993 Jul 2;261(5117):50–58. doi: 10.1126/science.8316857. [DOI] [PubMed] [Google Scholar]
- Sasamura T., Kobayashi T., Kojima S., Qadota H., Ohya Y., Masai I., Hotta Y. Molecular cloning and characterization of Drosophila genes encoding small GTPases of the rab and rho families. Mol Gen Genet. 1997 May 20;254(5):486–494. doi: 10.1007/s004380050443. [DOI] [PubMed] [Google Scholar]
- Saxton W. M., Hicks J., Goldstein L. S., Raff E. C. Kinesin heavy chain is essential for viability and neuromuscular functions in Drosophila, but mutants show no defects in mitosis. Cell. 1991 Mar 22;64(6):1093–1102. doi: 10.1016/0092-8674(91)90264-y. [DOI] [PubMed] [Google Scholar]
- Shelden E., Knecht D. A. Dictyostelium cell shape generation requires myosin II. Cell Motil Cytoskeleton. 1996;35(1):59–67. doi: 10.1002/(SICI)1097-0169(1996)35:1<59::AID-CM5>3.0.CO;2-D. [DOI] [PubMed] [Google Scholar]
- Strutt D. I., Weber U., Mlodzik M. The role of RhoA in tissue polarity and Frizzled signalling. Nature. 1997 May 15;387(6630):292–295. doi: 10.1038/387292a0. [DOI] [PubMed] [Google Scholar]
- Tan J. L., Ravid S., Spudich J. A. Control of nonmuscle myosins by phosphorylation. Annu Rev Biochem. 1992;61:721–759. doi: 10.1146/annurev.bi.61.070192.003445. [DOI] [PubMed] [Google Scholar]
- Valencia A., Chardin P., Wittinghofer A., Sander C. The ras protein family: evolutionary tree and role of conserved amino acids. Biochemistry. 1991 May 14;30(19):4637–4648. doi: 10.1021/bi00233a001. [DOI] [PubMed] [Google Scholar]
- Van Aelst L., D'Souza-Schorey C. Rho GTPases and signaling networks. Genes Dev. 1997 Sep 15;11(18):2295–2322. doi: 10.1101/gad.11.18.2295. [DOI] [PubMed] [Google Scholar]
- Watts F. Z., Shiels G., Orr E. The yeast MYO1 gene encoding a myosin-like protein required for cell division. EMBO J. 1987 Nov;6(11):3499–3505. doi: 10.1002/j.1460-2075.1987.tb02675.x. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Werner L. A., Manseau L. J. A Drosophila gene with predicted rhoGEF, pleckstrin homology and SH3 domains is highly expressed in morphogenic tissues. Gene. 1997 Mar 10;187(1):107–114. doi: 10.1016/s0378-1119(96)00732-9. [DOI] [PubMed] [Google Scholar]
- Williams-Masson E. M., Malik A. N., Hardin J. An actin-mediated two-step mechanism is required for ventral enclosure of the C. elegans hypodermis. Development. 1997 Aug;124(15):2889–2901. doi: 10.1242/dev.124.15.2889. [DOI] [PubMed] [Google Scholar]
- Wissmann A., Ingles J., McGhee J. D., Mains P. E. Caenorhabditis elegans LET-502 is related to Rho-binding kinases and human myotonic dystrophy kinase and interacts genetically with a homolog of the regulatory subunit of smooth muscle myosin phosphatase to affect cell shape. Genes Dev. 1997 Feb 15;11(4):409–422. doi: 10.1101/gad.11.4.409. [DOI] [PubMed] [Google Scholar]
- Yamochi W., Tanaka K., Nonaka H., Maeda A., Musha T., Takai Y. Growth site localization of Rho1 small GTP-binding protein and its involvement in bud formation in Saccharomyces cerevisiae. J Cell Biol. 1994 Jun;125(5):1077–1093. doi: 10.1083/jcb.125.5.1077. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Young P. E., Pesacreta T. C., Kiehart D. P. Dynamic changes in the distribution of cytoplasmic myosin during Drosophila embryogenesis. Development. 1991 Jan;111(1):1–14. doi: 10.1242/dev.111.1.1. [DOI] [PubMed] [Google Scholar]
- Young P. E., Richman A. M., Ketchum A. S., Kiehart D. P. Morphogenesis in Drosophila requires nonmuscle myosin heavy chain function. Genes Dev. 1993 Jan;7(1):29–41. doi: 10.1101/gad.7.1.29. [DOI] [PubMed] [Google Scholar]
- Zang J. H., Cavet G., Sabry J. H., Wagner P., Moores S. L., Spudich J. A. On the role of myosin-II in cytokinesis: division of Dictyostelium cells under adhesive and nonadhesive conditions. Mol Biol Cell. 1997 Dec;8(12):2617–2629. doi: 10.1091/mbc.8.12.2617. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Zhang F. L., Casey P. J. Protein prenylation: molecular mechanisms and functional consequences. Annu Rev Biochem. 1996;65:241–269. doi: 10.1146/annurev.bi.65.070196.001325. [DOI] [PubMed] [Google Scholar]
- Zhao D. B., Côté S., Jähnig F., Haller J., Jäckle H. Zipper encodes a putative integral membrane protein required for normal axon patterning during Drosophila neurogenesis. EMBO J. 1988 Apr;7(4):1115–1119. doi: 10.1002/j.1460-2075.1988.tb02920.x. [DOI] [PMC free article] [PubMed] [Google Scholar]
- von Kalm L., Fristrom D., Fristrom J. The making of a fly leg: a model for epithelial morphogenesis. Bioessays. 1995 Aug;17(8):693–702. doi: 10.1002/bies.950170806. [DOI] [PubMed] [Google Scholar]