Novel syntaxin homologue, Pep12p, required for the sorting of lumenal hydrolases to the lysosome-like vacuole in yeast.
AUTOR(ES)
Becherer, K A
RESUMO
pep12/vps6 mutants of Saccharomyces cerevisiae are defective in delivery of soluble vacuolar hydrolases to the vacuole. Morphological analysis by electron microscopy revealed that pep12 cells accumulate 40- to 50-nm vesicles. Furthermore, pep12 cells have enlarged vacuoles characteristic of class D pep/vps mutants. PEP12 encodes a protein of 288 amino acids that has a C-terminal hydrophobic region and shares significant sequence similarity with members of the syntaxin protein family. These proteins appear to participate in the docking and fusion of intracellular transport vesicles. Pep12p is the first member of the syntaxin family to be implicated in transport between the Golgi and the vacuole/lysosome. Pep12p-specific polyclonal antisera detected a 35-kDa protein that fractionated as an integral membrane protein. Subcellular fractionation experiments revealed that Pep12p was associated with membrane fractions of two different densities; the major pool (approximately 90%) of pep12p may associate with the endosome, while a minor pool (approximately 10%) cofractionated with the late Golgi marker Kex2p. These observations suggest that Pep12p may mediate the docking of Golgi-derived transport vesicles at the endosome.
ACESSO AO ARTIGO
http://www.pubmedcentral.nih.gov/articlerender.fcgi?artid=275911Documentos Relacionados
- A membrane-associated complex containing the Vps15 protein kinase and the Vps34 PI 3-kinase is essential for protein sorting to the yeast lysosome-like vacuole.
- Mutant defective in processing of an enzyme located in the lysosome-like vacuole of Saccharomyces cerevisiae.
- Novel PI(4)P 5-kinase homologue, Fab1p, essential for normal vacuole function and morphology in yeast.
- Identification of the amino acid sequence that targets peroxiredoxin 6 to lysosome-like structures of lung epithelial cells
- An Arabidopsis syntaxin homologue isolated by functional complementation of a yeast pep12 mutant.