Stm1p, a ribosome-associated protein, is important for protein synthesis in Saccharomyces cerevisiae under nutritional stress conditions.
Stm1p is a Saccharomyces cerevisiae protein that has been implicated in several biological processes, ranging from apoptosis to telomere biosynthesis. Likewise, Stm1p has been identified as a protein associated with supramolecular structures, including ribosomes and nuclear telomere cap complexes. Using a variety of biochemical methods, we found that the vast majority of cellular Stm1p is associated with free cytosolic 80S ribosomes and polysomes. In its association with ribosomes, Stm1p interacts in an equimolar complex with both ribosomal subunits and is not associated with mRNA. Functionally, targeted disruption of the STM1 gene results in rapamycin hypersensitivity and a defect in recovery following nitrogen starvation and replenishment. These effects coincide with severe polysome depletion and reduced total protein synthesis. Taken together, our data indicate that Stm1p plays a critical role in facilitating translation under nutrient stress conditions and suggest that Stm1p acts in concert with the target of rapamycin (TOR) signaling pathway.
Department of Molecular and Cellular Oncology, Unit 079, The University of Texas M. D. Anderson Cancer Center, 1515 Holcombe Boulevard, Houston, TX 77030-4009, USA.
Natalya
N
Van Dyke
Johnson
J
Baby
Michael W
MW
Van Dyke
D000935:Antifungal Agents / Q000494:pharmacology; D003470:Culture Media; D018390:Gene Targeting; D005800:Genes, Fungal; D009584:Nitrogen / Q000378:metabolism; D014176:Protein Biosynthesis / Q000187:drug effects; D017346:Protein Serine-Threonine Kinases; D012270:Ribosomes / Q000378:metabolism; D012441:Saccharomyces cerevisiae / Q000187:drug effects / Q000235:genetics / Q000378:metabolism*; D029701:Saccharomyces cerevisiae Proteins / Q000235:genetics / Q000378:metabolism*; D015398:Signal Transduction; D020123:Sirolimus / Q000494:pharmacology
D000935:Antifungal Agents; D003470:Culture Media; D029701:Saccharomyces cerevisiae Proteins; D017346:Protein Serine-Threonine Kinases; C500749:target of rapamycin protein, S cerevisiae; D009584:Nitrogen; D020123:Sirolimus