Dauer pheromone and G-protein signaling modulate the coordination of intraflagellar transport kinesin motor proteins 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.

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Faculty Opinions recommendation of Heterotrimeric G protein signaling functions with dynein to promote spindle positioning in C. elegans.

Faculty Opinions – Post-Publication Peer Review of the Biomedical Literature ◽

10.3410/f.1092303.549957 ◽

2007 ◽

Author(s):

Michel Labouesse

Keyword(s):

G Protein ◽

G Protein Signaling ◽

Protein Signaling ◽

Heterotrimeric G Protein ◽

Spindle Positioning ◽

C Elegans ◽

Heterotrimeric G Protein Signaling

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Multiple RGS proteins alter neural G protein signaling to allow C. elegans to rapidly change behavior when fed

Genes & Development ◽

10.1101/gad.14.16.2003 ◽

2000 ◽

Vol 14 (16) ◽

pp. 2003-2014 ◽

Cited By ~ 2

Author(s):

Meng-Qiu Dong ◽

Daniel Chase ◽

Georgia A. Patikoglou ◽

Michael R. Koelle

Keyword(s):

G Protein ◽

Egg Laying ◽

G Protein Signaling ◽

Rgs Proteins ◽

Protein Signaling ◽

C Elegans ◽

Change Behavior ◽

Rgs Protein ◽

Heterotrimeric G Protein Signaling

Regulators of G protein signaling (RGS proteins) inhibit heterotrimeric G protein signaling by activating G protein GTPase activity. Many mammalian RGS proteins are expressed in the brain and can act in vitro on the neural G protein Go, but the biological purpose of this multiplicity of regulators is not clear. We have analyzed all 13 RGS genes in Caenorhabditis elegans and found that three of them influence the aspect of egg-laying behavior controlled by Go signaling. A previously studied RGS protein, EGL-10, affects egg laying under all conditions tested. The other two RGS proteins, RGS-1 and RGS-2, act as Go GTPase activators in vitro but, unlike EGL-10, they do not strongly affect egg laying when worms are allowed to feed constantly. However, rgs-1; rgs-2double mutants fail to rapidly induce egg-laying behavior when refed after starvation. Thus EGL-10 sets baseline levels of signaling, while RGS-1 and RGS-2 appear to redundantly alter signaling to cause appropriate behavioral responses to food.

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