Sense and sensibility: nutritional response and signal integration in yeast.

Yeast cells respond to the quantity and quality of carbon and nitrogen sources in the environment both by adjusting their transcriptional and metabolic profiles to make optimum use of the available nutrients and by selecting a developmental program--budding, pseudohyphal differentiation, quiescence or sporulation--that maximizes their potential for survival under the existing nutrient conditions. Recent studies fueled by genomic tools have refined our knowledge of the components and connections within individual pathways and the interconnections between pathways. More significantly, these studies begin to paint an as yet inchoate portrait of the yeast cells' means of processing its environmental information, in which specific transcription factors and chromatin modifying activities coordinate input from several signaling pathways to yield an appropriate and coherent response of genes involved in mass accumulation and metabolism.