RRC ID 897
Author Nakamura-Kubo M, Nakamura T, Hirata A, Shimoda C.
Title The fission yeast spo14+ gene encoding a functional homologue of budding yeast Sec12 is required for the development of forespore membranes.
Journal Mol Biol Cell
Abstract The Schizosaccharomyces pombe spo14-B221 mutant was originally isolated as a sporulation-deficient mutant. However, the spo14(+) gene is essential for cell viability and growth. spo14(+) is identical to the previously characterized stl1(+) gene encoding a putative homologue of Saccharomyces cerevisiae Sec12, which is essential for protein transport from the endoplasmic reticulum (ER) to the Golgi apparatus. In the spo14 mutant cells, ER-like membranes were accumulated beneath the plasma membrane and the ER/Golgi shuttling protein Rer1 remained in the ER. Sec12 is a guanine nucleotide exchange factor for the Sar1 GTPase. Overproduction of psr1(+) coding for an S. pombe Sar1 homologue suppressed both the sporulation defect of spo14-B221 and cold-sensitive growth of newly isolated spo14-6 and spo14-7 mutants. These results indicate that Spo14 is involved in early steps of the protein secretory pathway. The spo14-B221 allele carries a single nucleotide change in the branch point consensus of the fifth intron, which reduces the abundance of the spo14 mRNA. During meiosis II, the forespore membrane was initiated near spindle pole bodies; however, subsequent extension of the membrane was arrested before its closure into a sac. We conclude that Spo14 is responsible for the assembly of the forespore membrane by supplying membrane vesicles.
Volume 14(3)
Pages 1109-24
Published 2003-3-1
DOI 10.1091/mbc.e02-08-0504
PMID 12631727
PMC PMC151583
MeSH Amino Acid Sequence Base Sequence Cell Membrane / metabolism* Endoplasmic Reticulum / metabolism Genes, Fungal* Golgi Apparatus / metabolism Guanine Nucleotide Exchange Factors Membrane Glycoproteins / genetics Membrane Glycoproteins / metabolism* Molecular Sequence Data Mutation Phenotype Recombinant Fusion Proteins / metabolism Saccharomyces cerevisiae / metabolism Saccharomyces cerevisiae Proteins / genetics Saccharomyces cerevisiae Proteins / metabolism* Schizosaccharomyces / genetics Schizosaccharomyces / physiology* Schizosaccharomyces / ultrastructure Schizosaccharomyces pombe Proteins / chemistry Schizosaccharomyces pombe Proteins / genetics* Schizosaccharomyces pombe Proteins / metabolism* Spores, Fungal / metabolism* Transport Vesicles / metabolism
IF 3.905
Times Cited 40
Yeast TN29 TN8 ? TN52 MKW5 MK14L RM14 RM14-7 TN196 TN226