The transduction of the nitrogen regulation signal in Saccharomyces cerevisiae.
In cells of Saccharomyces cerevisiae, using ammonia as a source of nitrogen, Gln3p is sequestered in the cytoplasm by Ure2p but enters the nucleus when the cells are shifted to a nonpreferred source of nitrogen such as proline. The interpretation of recently published observations provides evidence for the view that Ure2p is the sensor for a drop in the intracellular concentration of glutamine, a signal that results in the polyubiquitination of the vesicle responsible for retaining the Gln3p-Ure2p complex in the cytoplasm. As a consequence of the drop in glutamine concentration, Gln3p is able to enter the nucleus and to activate the transcription of nitrogen-regulated genes.
Magasanik
Boris
B
Department of Biology, Massachusetts Institute of Technology, Cambridge, MA 02139, USA. bmag@mit.edu
D000199:Actins / Q000378:metabolism; D002467:Cell Nucleus / Q000378:metabolism; D003593:Cytoplasm / Q000378:metabolism; D003599:Cytoskeleton / Q000378:metabolism; D005979:Glutathione Peroxidase; D009584:Nitrogen / Q000378:metabolism*; D011328:Prions / Q000378:metabolism; D012097:Repressor Proteins / Q000378:metabolism*; D012441:Saccharomyces cerevisiae / Q000378:metabolism*; D029701:Saccharomyces cerevisiae Proteins / Q000378:metabolism*; D015398:Signal Transduction; D014157:Transcription Factors / Q000378:metabolism*
D000199:Actins; C071664:GLN3 protein, S cerevisiae; D011328:Prions; D012097:Repressor Proteins; D029701:Saccharomyces cerevisiae Proteins; D014157:Transcription Factors; D005979:Glutathione Peroxidase; C067020:URE2 protein, S cerevisiae; D009584:Nitrogen