Regulation of Cdc42/Rac Signaling in the Establishment of Cell Polarity and Control of Cell Motility
Abstract
Since the inception of this project, a number of reports have highlighted different new and exciting aspects of the molecular biology of Bem1p, the scaffold protein in the yeast complex similar to the mammalian PIX complex. These include the discovery that the PX domain is a novel phosphoinositide binding domain, and the structure and characterization of the Cdc24p-interacting PB1 domain. These reports provided new insights into the molecular features of Bem1p. As a result, it became more urgent to explore previously unforeseen aspects of Bem1p function in the context of cell polarization. In this report, I describe a series of very productive studies aimed at increasing our understanding of the actual molecular mechanism of the establishment of cell polarity. We demonstrate that the cytoskeleton (both actin and microtubules) is dispensable for the establishment of cell polarization, a surprising result that has broad implications for other cell types. Furthermore, we show that Bem1p is essential for polarity establishment in the absence of cortical cues. Capitalizing on our previous discoveries and work by others, we show that the SH3-2, PX, and PB1 domains are essential for this role. We also have preliminary evidence that PI binding may play a significant role in polarity establishment.
Document Details
- Document Type
- Technical Report
- Publication Date
- Aug 01, 2002
- Accession Number
- ADA410349
Entities
People
- Daniel J Lew
- Javier E. Irazoqui
Organizations
- Duke University Hospital