POSTERS - BLAST X - University of Utah

BLAST X Poster #78
PHENOTYPIC CHARACTERIZATION OF ALL SINGLE MUTANTS OF TWO COMPONENT
SYSTEM PROTEINS IN NEUROSPORA CRASSA
Barba C., Chavez-Canales M., Salas G., Hernandez C., Sanchez O and Georgellis D.
Department of Molecular Genetics, Instituto de Fisiologia Celular, UNAM
Perception and response to environmental stimuli is essential for the growth and survival
of all organisms. The sensing and processing of these stimuli are carried out by molecular
circuits within the cell, which detect, amplify and integrate them into a specific response. In
prokaryotes these molecular circuits are typically organized by protein pairs, "sensory kinase"
proteins (SK) and "response regulator" proteins (RR) that belong to the large family of two
component systems (TCS). This organization implies that each SK activates its cognate RR,
and thus providing specificity to signal propagation and output. However, an interesting variation
of TCS architecture is observed in filamentous fungi where multiple SKs appear to use a single
phosphotransfer protein to relay signals to a few RRs. Therefore, the question of whether a
specific signal can generate a specific response, or whether the various signals sensed by
individual SKs result in the same response, is raised. To explore this intriguing question we
used Neurospora crassa, which has eleven SKs, one phosphotransfer protein and three RRs,
as our model. Here, by using single mutants of all SKs and RRs, we demonstrate that these
signaling cascades are involved in the regulation of various developmental processes, and in
responses to environmental conditions, such as osmotic, oxidative and fungicide stress.
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