Principles of actomyosin contractility regulation in C. elegans

Actomyosin structures power a variety of essential cell and tissue-level processes requiring force, such as cell division, migration, morphogenesis and wound repair. A network of proteins, including actin binding proteins, myosin phosphorylation regulators, and RhoGTPases and their regulators (collectively referred to as the Contractome), regulates the assembly and contraction of actomyosin structures in specific cellular locations at specific times. How this regulation works in vivo is still poorly understood. We are addressing this question in the model organism C. elegans. In my talk, I will present our results on the function and regulation of contractility in several stages of C. elegans reproduction, namely syncytial germline architecture, oocyte transit through the spermatheca and embryogenesis. Several generalizable principles emerge from our findings: the architecture of the actomyosin network – determined by actin binding protein – is critically important for its function; spatiotemporal regulation is achieved by tissue-specific expression and subcellular localization of Rho GTPase regulators; and mechano-molecular feedback mechanisms exist to coordinate between external forces and intracellular contractility.