Edwin Munro (Univ. of Chicago)

Edwin Munro (Univ. of Chicago)

Butler Seminar Series

Event Date/Location

May 17, 2017 - 12:00 pm
Thomas Laboratory 003

Speaker

Topic

Dynamical basis for self-organizing cortical polarity in early C. elegans embryos

Abstract: We are using the C. elegans zygote as a model to understand basic principles that govern self-organizing cortical polarity.  Zygotic polarity is specified by the asymmetric enrichment of highly conserved polarity determinants, known as PAR proteins, into complementary anterior and posterior cortical domains. PAR asymmetries are established in response to a transient sperm-derived cue and then dynamically maintained, after the cue is gone, through local PAR protein interactions and local coupling to the cortical actomyosin cytoskeleton. Our goal is to understand how robust, self-stabilizing, cortical polarity emerges through these local interactions.  In this talk, I will summarize our current understanding of how this works, focusing on three main organizing principles: (1) Mutual antagonism, in which anterior and posterior PAR proteins compete with one another to inhibit cortical binding and/or activity; (2) local clustering of polarity proteins, which leads to ultrasensitive dependence of cortical binding on the densities of proteins and their local antagonists, and which couples polarity proteins to the actomyosin cortex; and (3) mechanochemical feedback coupling in which PAR proteins modulate actomyosin contractility and cortical flows to promote (or inhibit) their own redistribution.

Audience

Free and open to the university community and the public.

Host

Danelle Devenport, Department of Molecular Biology