A link between secretion and pre-mRNA processing defects in Saccharomyces cerevisiae and the identification of a novel splicing gene, RSE1.
Secretory proteins in eukaryotic cells are transported to the cell surface via the endoplasmic reticulum (ER) and the Golgi apparatus by membrane-bounded vesicles. We screened a collection of temperature-sensitive mutants of Saccharomyces cerevisiae for defects in ER-to-Golgi transport. Two of the genes identified in this screen were PRP2, which encodes a known pre-mRNA splicing factor, and RSE1, a novel gene that we show to be important for pre-mRNA splicing. Both prp2-13 and rse1-1 mutants accumulate the ER forms of invertase and the vacuolar protease CPY at restrictive temperature. The secretion defect in each mutant can be suppressed by increasing the amount of SAR1, which encodes a small GTPase essential for COPII vesicle formation from the ER, or by deleting the intron from the SAR1 gene. These data indicate that a failure to splice SAR1 pre-mRNA is the specific cause of the secretion defects in prp2-13 and rse1-1. Moreover, these data imply that Sar1p is a limiting component of the ER-to-Golgi transport machinery and suggest a way that secretory pathway function might be coordinated with the amount of gene expression in a cell.
Chen
E J
EJ
Department of Biology, Massachusetts Institute of Technology, Cambridge, Massachusetts 02139, USA.
Frand
A R
AR
Chitouras
E
E
Kaiser
C A
CA
D000483:Alleles; D000595:Amino Acid Sequence; D017124:Conserved Sequence / Q000235:genetics; D053487:DEAD-box RNA Helicases; D005656:Fungal Proteins / Q000235:genetics; D019204:GTP-Binding Proteins / Q000235:genetics; D005800:Genes, Fungal / Q000235:genetics*; D017930:Genes, Reporter; D006026:Glycoside Hydrolases / Q000235:genetics / Q000378:metabolism; D006031:Glycosylation; D008969:Molecular Sequence Data; D020559:Monomeric GTP-Binding Proteins; D009154:Mutation / Q000235:genetics; D012322:RNA Precursors / Q000235:genetics*; D012323:RNA Processing, Post-Transcriptional / Q000235:genetics*; D012326:RNA Splicing / Q000235:genetics*; D012441:Saccharomyces cerevisiae / Q000235:genetics*; D029701:Saccharomyces cerevisiae Proteins; D016415:Sequence Alignment; D013696:Temperature; D033921:Vesicular Transport Proteins; D043324:beta-Fructofuranosidase
D005656:Fungal Proteins; D012322:RNA Precursors; D029701:Saccharomyces cerevisiae Proteins; D033921:Vesicular Transport Proteins; D006026:Glycoside Hydrolases; D043324:beta-Fructofuranosidase; D019204:GTP-Binding Proteins; C066490:PRP2 protein, S cerevisiae; D053487:DEAD-box RNA Helicases; D020559:Monomeric GTP-Binding Proteins; C077395:SAR1 protein, S cerevisiae