Heterotrimeric G protein signaling functions with dynein to promote spindle positioning in C. elegans.
Proper orientation and positioning of the mitotic spindle is essential for the correct segregation of fate determinants during asymmetric cell division. Although heterotrimeric G proteins and their regulators are essential for spindle positioning in many cell types, their mechanism of action remains unclear. In this study, we show that dyrb-1, which encodes a dynein light chain, provides a functional link between heterotrimeric G protein signaling and dynein activity during spindle positioning in Caenorhabditis elegans. Embryos depleted of dyrb-1 display phenotypes similar to a weak loss of function of dynein activity, indicating that DYRB-1 is a positive regulator of dynein. We find that the depletion of dyrb-1 enhances the spindle positioning defect of weak loss of function alleles of two regulators of G protein signaling, LIN-5 and GPR-1/2, and that DYRB-1 physically associates with these two proteins. These results indicate that dynein activity functions with regulators of G protein signaling to regulate common downstream effectors during spindle positioning in the early C. elegans embryo.
Couwenbergs
Claudia
C
ETH Zurich, Institute of Biochemistry, 8093 Zurich, Switzerland.
Labbé
Jean-Claude
JC
Goulding
Morgan
M
Marty
Thomas
T
Bowerman
Bruce
B
Gotta
Monica
M
D000818:Animals; D017173:Caenorhabditis elegans / Q000235:genetics / Q000378:metabolism* / Q000648:ultrastructure; D029742:Caenorhabditis elegans Proteins / Q000037:antagonists & inhibitors / Q000378:metabolism / Q000502:physiology*; D004398:Dyneins / Q000037:antagonists & inhibitors / Q000378:metabolism* / Q000502:physiology; D004625:Embryo, Nonmammalian / Q000378:metabolism / Q000648:ultrastructure; D049452:Green Fluorescent Proteins / Q000032:analysis; D020962:Heterotrimeric GTP-Binding Proteins / Q000378:metabolism / Q000502:physiology*; D008954:Models, Biological; D034622:RNA Interference; D011993:Recombinant Fusion Proteins / Q000032:analysis; D015398:Signal Transduction; D008941:Spindle Apparatus / Q000378:metabolism* / Q000648:ultrastructure
D029742:Caenorhabditis elegans Proteins; C475458:G protein regulator 1, C elegans; C475459:G protein regulator 2, C elegans; D011993:Recombinant Fusion Proteins; D049452:Green Fluorescent Proteins; D004398:Dyneins; C525402:Dyrb-1 protein, C elegans; D020962:Heterotrimeric GTP-Binding Proteins