Connections in yeast cell polarity.
Genetics and biochemistry have been used to map many of the individual pathways that establish and maintain cell polarity in yeast, but Drees et al. (page 549) have now produced the equivalent of an aerial photograph of these processes. Using a high-throughput yeast two-hybrid screen, the authors assayed the universe of likely protein–protein interactions involved in cell polarity development. The resulting protein interaction map provides tantalizing insights and identifies dozens of potential mechanistic connections worth closer examination.
The authors used 68 yeast proteins associated with the actin cytoskeleton, septins, the secretory apparatus, and Rho-type GTPases as baits in parallel two-hybrid screens covering ∼90% of the predicted Saccharomyces cerevisiae ORFs. The screen uncovered 128 novel protein–protein interactions, including 44 involving previously uncharacterized proteins. The appearance of known interactions in the screen, along with subcellular localization studies, suggests that many...
