Distinct roles for Galpha and Gbetagamma in regulating spindle position and orientation in Caenorhabditis elegans embryos.
Correct placement and orientation of the mitotic spindle is essential for segregation of localized components and positioning of daughter cells. Although these processes are important in many cells, few factors that regulate spindle placement are known. Previous work has shown that GPB-1, the Gbeta subunit of a heterotrimeric G protein, is required for orientation of early cell division axes in C. elegans embryos. Here we show that GOA-1 (a Galphao) and the related GPA-16 are the functionally redundant Galpha subunits and that GPC-2 is the relevant Ggamma subunit that is required for spindle orientation in the early embryo. We show that Galpha and Gbetagamma are involved in controlling distinct microtubule-dependent processes. Gbetagamma is important in regulating migration of the centrosome around the nucleus and hence in orientating the mitotic spindle. Galpha is required for asymmetric spindle positioning in the one-celled embryo.
Wellcome/CRC Institute, Tennis Court Road, Cambridge, CB2 1QR, UK.
M
M
Gotta
J
J
Ahringer
D000818:Animals; D017173:Caenorhabditis elegans / Q000196:embryology* / Q000502:physiology; D002455:Cell Division / Q000502:physiology; D018385:Centrosome / Q000378:metabolism; D004625:Embryo, Nonmammalian / Q000166:cytology / Q000502:physiology*; D043802:GTP-Binding Protein alpha Subunits, Gq-G11; D044387:GTP-Binding Protein beta Subunits; D044388:GTP-Binding Protein gamma Subunits; D020962:Heterotrimeric GTP-Binding Proteins / Q000737:chemistry / Q000235:genetics / Q000378:metabolism*; D008845:Microinjections; D008856:Microscopy, Fluorescence; D008870:Microtubules / Q000378:metabolism*; D021122:Protein Subunits; D012313:RNA / Q000378:metabolism; D008941:Spindle Apparatus / Q000502:physiology*
C118981:G-protein Beta gamma; D044387:GTP-Binding Protein beta Subunits; D044388:GTP-Binding Protein gamma Subunits; D021122:Protein Subunits; D012313:RNA; C112631:G protein alpha 16; D043802:GTP-Binding Protein alpha Subunits, Gq-G11; D020962:Heterotrimeric GTP-Binding Proteins