Mapping of sporulation-specific functions in the yeast syntaxin gene SSO1.
The yeast Saccharomyces cerevisiae has two closely related plasma membrane syntaxins, Sso1p and Sso2p, which together provide an essential function in vegetative cells. However, Sso1p is also specifically needed during sporulation; and this function cannot be provided by Sso2p. We used fusions between SSO1 and SSO2 to map the sporulation-specific function of SSO1. We found that the two N-terminal alpha-helices Ha and Hb of Sso1p are important for sporulation, since it is reduced 8-fold for fusions where Ha and Hb are derived from Sso2p. In contrast, the C-terminal half of Sso1p does not seem to be specifically required for sporulation. Surprisingly, we further found that the 3' untranslated region (3'UTR) of SSO1 is essential for sporulation. Western blots failed to reveal a preferential expression of Sso1p in sporulating cells, indicating that effects on gene expression are unlikely to explain why the SSO1 3'UTR is needed for sporulation.
Oyen
Mattias
M
Department of Plant Biology and Forest Genetics, Swedish University of Agricultural Sciences, Box 7080, 75007 Uppsala, Sweden.
Jäntti
Jussi
J
Keränen
Sirkka
S
Ronne
Hans
H
D020413:3' Untranslated Regions; D019677:Artificial Gene Fusion; D002874:Chromosome Mapping; D017353:Gene Deletion; D005800:Genes, Fungal; D008540:Meiosis; D008565:Membrane Proteins / Q000737:chemistry / Q000235:genetics* / Q000502:physiology; D010641:Phenotype; D017434:Protein Structure, Tertiary; D050765:Qa-SNARE Proteins; D012441:Saccharomyces cerevisiae / Q000235:genetics* / Q000502:physiology*; D029701:Saccharomyces cerevisiae Proteins / Q000737:chemistry / Q000235:genetics* / Q000502:physiology; D013172:Spores, Fungal / Q000235:genetics / Q000502:physiology
D020413:3' Untranslated Regions; D008565:Membrane Proteins; D050765:Qa-SNARE Proteins; C084006:SSO1 protein, S cerevisiae; C084007:SSO2 protein, S cerevisiae; D029701:Saccharomyces cerevisiae Proteins