INVESTIGADORES
COUTO Alicia Susana
artículos
Título:
Pheromone-induced morphogenesis improves osmoadaptation capacity by activating the HOG MAPK pathway.
Autor/es:
RODRIGO BALTANÁS; ALAN BUSH; ALICIA S. COUTO; LUCÍA DURRIEU; STEFAN HOHMANN; ALEJANDRO COLMAN-LERNER
Revista:
SCIENCE SIGNALING
Editorial:
AMER ASSOC ADVANCEMENT SCIENCE
Referencias:
Año: 2013 vol. 6 p. 1 - 14
ISSN:
1937-9145
Resumen:
Environmental and internal conditions expose cells to a multiplicity of stimuli whose consequences are
difficult to predict. We investigate the response to mating pheromone of yeast cells adapted to high
osmolarity. Events downstream of pheromone binding involve two mitogen-activated protein kinase
(MAPK) cascades: the pheromone response (PR) and the cell wall integrity (CWI) response. Although the PR
MAPK pathway shares components with a third MAPK pathway, the high osmolarity (HOG) response, each
one is normally only activated by its cognate stimulus, a phenomenon called insulation. We found that in
cells adapted to high osmolarity, PR activated the HOG pathway in a pheromone- and osmolarity-dependent
manner. Activation of HOG by the PR was not due to loss of insulation, but rather a response to a reduction
in internal osmolarity, which resulted from an increase in glycerol release caused by the PR. By analyzing
single-cell time courses, we found that stimulation of HOG occurred in discrete bursts that coincided with
the shmooing morphogenetic process. Activation required the polarisome, the CWI MAPK Slt2, and the
aquaglyceroporin Fps1. HOG activation resulted in high glycerol turnover, which improved adaptability to
rapid changes in osmolarity. Our work shows how a differentiation signal can recruit a second, unrelated
sensory pathway to fine-tune yeast response in a complex environment.