A conditional yeast mutant deficient in mRNA transport from nucleus to cytoplasm.
Transport of mRNA from nucleus to cytoplasm is critical for eukaryotic gene expression; however, the mechanism of export is unknown. Selection and screening procedures have therefore been used to obtain a family of temperature-sensitive conditional mutants of Saccharomyces cerevisiae that accumulate poly(A)+ RNA in the nucleus when incubated at 37 degrees C, as judged by in situ hybridization. In one such mRNA transport mutant, mtr1-1, RNA synthesis continues, the export of poly(A)+ RNA is inhibited, intranuclear poly(A)+ is remarkably stable, and protein synthesis gradually stops. Thus, there is no tight coupling between RNA synthesis and export. The export lesion is reversible. Although mRNA export is clearly not a default option, neither inhibition of protein synthesis, inhibition of mRNA splicing, nor inhibition of poly(A)-binding protein function blocks export of the average poly(A)+, as judged by in situ hybridization. Further analysis of the family of mtr mutants should help map the path of RNA transport.
Kadowaki
T
T
Institute of Pathology, Case Western Reserve University, Cleveland, OH 44106.
Zhao
Y
Y
Tartakoff
A M
AM
D000255:Adenosine Triphosphate / Q000378:metabolism; D002467:Cell Nucleus / Q000378:metabolism*; D003593:Cytoplasm / Q000378:metabolism; D005656:Fungal Proteins / Q000096:biosynthesis; D005800:Genes, Fungal; D007700:Kinetics; D009154:Mutation; D010641:Phenotype; D011061:Poly A / Q000378:metabolism; D012313:RNA / Q000378:metabolism; D012333:RNA, Messenger / Q000378:metabolism*; D012441:Saccharomyces cerevisiae / Q000235:genetics* / Q000378:metabolism; D013696:Temperature; D014158:Transcription, Genetic; D001616:beta-Galactosidase / Q000235:genetics / Q000378:metabolism
D005656:Fungal Proteins; D012333:RNA, Messenger; D011061:Poly A; D012313:RNA; D000255:Adenosine Triphosphate; D001616:beta-Galactosidase