Connections between integrins and Rac GTPase pathways control gonad formation and function in C. elegans.
The integrins are a family of alphabeta heterodimeric transmembrane receptors that link extracellular matrix (ECM) proteins to the cytoskeleton and orchestrate cell behaviors. It's been suggested that integrins interact with Rho family small GTPases, such as Rho and Rac. We took advantage of a C. elegans nematode line expressing HA-betatail, a beta integrin transgene inhibiting the functions of endogenous integrins, to determine the combined effects of reducing PAT-3 beta integrin and Rac pathway activities. Double mutants of HA-betatail and unc-73, a guanine nucleotide exchange factor GEF for MIG-2/Rac, had body wall and vulval muscle abnormalities. On the other hand, HA-betatail combined with mutant CED-5, another Rac interacting protein, showed ovulation defects and sterility. RNA-mediated interference (RNAi) of pat-3 on Rac mutant backgrounds also affected gonad structure and function. These results show a functional link between integrins and Rac signaling in muscles and gonads. Furthermore, data showing distinct phenotypes of HA-betatail with unc-73 versus ced-5 suggest some tissue-specificity in the usage of Rac signaling pathways.
Lee
Myeongwoo
M
Department of Biology, Baylor University, One Bear Place 97388, Waco, TX 76798, United States. Myeongwoo_Lee@baylor.edu
Shen
Bing
B
Schwarzbauer
Jean E
JE
Ahn
Jeong
J
Kwon
John
J
D000818:Animals; D017173:Caenorhabditis elegans / Q000502:physiology*; D029742:Caenorhabditis elegans Proteins / Q000502:physiology*; D006066:Gonads / Q000196:embryology* / Q000502:physiology; D039641:Integrin beta Chains / Q000502:physiology*; D008124:Locomotion; D008565:Membrane Proteins / Q000502:physiology; D009024:Morphogenesis; D009132:Muscles / Q000502:physiology; D009419:Nerve Tissue Proteins / Q000502:physiology*; D009928:Organ Specificity; D034622:RNA Interference; D015398:Signal Transduction / Q000502:physiology*; D020744:rac GTP-Binding Proteins / Q000502:physiology*
C111579:CED-5 protein, C elegans; D029742:Caenorhabditis elegans Proteins; D039641:Integrin beta Chains; D008565:Membrane Proteins; D009419:Nerve Tissue Proteins; C111263:UNC-73 protein, C elegans; C093515:pat-3 protein, C elegans; D020744:rac GTP-Binding Proteins