Heterologous expression of syntaxin 6 in Saccharomyces cerevisiae
Götte, M.; Stadtbäumer, A.
Biological Research 35(3-4): 347-357
2002
ISSN/ISBN: 0716-9760 PMID: 12462987 Document Number: 551358
The molecular mechanisms of vesicular protein transport in eukaryotic cells are highly conserved. Members of the syntaxin family play a pivotal role in the membrane fusion process. We have expressed rat syntaxin 6 and its cytoplasmic domain in wild-type and pep 12 mutant strains of Saccharomyces cerevisiae to elucidate the role of the syntaxin 6-dependent vesicular trafficking step in yeast. Immunofluorescence microscopy revealed a punctate, Golgi-like staining pattern for syntaxin 6, which only partially overlapped with Pep 12p in wild-type yeast cells. In contrast to Pep 12p, syntaxin 6 was not mislocalized to the vacuole upon expression from 2 micron vectors, which might be attributed to conserved sorting and retention signals. Syntaxin 6 was not capable of complementing the sorting and maturation defects of the vacuolar hydrolase CPY in pep 12 null mutants. No dominant negative effects of either syntaxin 6 or syntaxin 6DELTAC overexpression on CPY sorting and maturation were observed in wild-type yeast cells. We conclude that syntaxin 6 and Pep 12p do not act at the same vesicular trafficking step(s) in yeast and higher eukaryotes.