Life in the midst of scarcity: adaptations to nutrient availability in Saccharomyces cerevisiae.
Cells of all living organisms contain complex signal transduction networks to ensure that a wide range of physiological properties are properly adapted to the environmental conditions. The fundamental concepts and individual building blocks of these signalling networks are generally well-conserved from yeast to man; yet, the central role that growth factors and hormones play in the regulation of signalling cascades in higher eukaryotes is executed by nutrients in yeast. Several nutrient-controlled pathways, which regulate cell growth and proliferation, metabolism and stress resistance, have been defined in yeast. These pathways are integrated into a signalling network, which ensures that yeast cells enter a quiescent, resting phase (G0) to survive periods of nutrient scarceness and that they rapidly resume growth and cell proliferation when nutrient conditions become favourable again. A series of well-conserved nutrient-sensory protein kinases perform key roles in this signalling network: i.e. Snf1, PKA, Tor1 and Tor2, Sch9 and Pho85-Pho80. In this review, we provide a comprehensive overview on the current understanding of the signalling processes mediated via these kinases with a particular focus on how these individual pathways converge to signalling networks that ultimately ensure the dynamic translation of extracellular nutrient signals into appropriate physiological responses.
Smets
Bart
B
Laboratory of Functional Biology, Katholieke Universiteit Leuven, Kasteelpark Arenberg 31, Box 2433, 3001 Heverlee, Belgium.
Ghillebert
Ruben
R
De Snijder
Pepijn
P
Binda
Matteo
M
Swinnen
Erwin
E
De Virgilio
Claudio
C
Winderickx
Joris
J
D009747:Nutritional Physiological Phenomena / Q000502:physiology*; D011494:Protein Kinases / Q000378:metabolism / Q000502:physiology; D012441:Saccharomyces cerevisiae / Q000502:physiology*; D015398:Signal Transduction
D011494:Protein Kinases