The Daily Bulletin

Please join the Biology Department for the seminar "Signaling Pathways That Control Morphogenesis in Fungi," presented by Paul J. Cullen, professor and director of graduate studies in the University at Buffalo's Department of Biological Sciences, on Monday, September 16, from 3:00 to 3:50 p.m. in Technology Building 160. All students, staff, and faculty are welcome.

Abstract
Signal transduction pathways regulate developmental transitions by sensing environmental stimuli and coordinating morphogenetic responses. One type of pathway is MAPK pathways, which regulate changes in cell shape and the response to stress in many eukaryotes. In fungal species, MAP kinase pathways control a foraging behavior called filamentous growth. Filamentous growth in many fungal pathogens is required for virulence. We study filamentous growth regulation in budding yeast, which provides a convenient genetic model for understanding the proteins that regulate MAPK signaling. A remarkable feature of the yeast filamentous growth (fMAPK) pathway is that it shares components with MAPK pathways that have other functions in the cell. Specificity of the fMAPK pathway comes from a pathway-specific transcription factor, a pathway-dedicated MAP kinase, and scaffold type-adaptors. Specificity also resides at the cell surface, by activation of a mucin-type glycoprotein and by positional landmarks called bud-site-selection proteins. These proteins converge on a Rho-type GTPase called Cdc42 which is itself a master regulator of signaling and cell polarity (shape). We seek to understand how Cdc42 is directed to the fMAPK pathway and how mucin-type receptors regulate cell differentiation in this relevant model system.