Details:

Alternative Title:
J Cell Biol
Description:
Organelle acidification plays a demonstrable role in intracellular protein processing, transport, and sorting in animal cells. We investigated the relationship between acidification and protein sorting in yeast by treating yeast cells with ammonium chloride and found that this lysosomotropic agent caused the mislocalization of a substantial fraction of the newly synthesized vacuolar (lysosomal) enzyme proteinase A (PrA) to the cell surface. We have also determined that a subset of the vpl mutants, which are deficient in sorting of vacuolar proteins (Rothman, J. H., and T. H. Stevens. 1986. Cell. 47:1041-1051; Rothman, J. H., I. Howald, and T. H. Stevens. EMBO [Eur. Mol. Biol. Organ.] J. In press), failed to accumulate the lysosomotropic fluorescent dye quinacrine within their vacuoles, mimicking the phenotype of wild-type cells treated with ammonium. The acidification defect of vpl3 and vpl6 mutants correlated with a marked deficiency in vacuolar ATPase activity, diminished levels of two immunoreactive subunits of the protontranslocating ATPase (H+-ATPase) in purified vacuolar membranes, and accumulation of the intracellular portion of PrA as the precursor species. Therefore, some of the VPL genes are required for the normal function of the yeast vacuolar H+-ATPase complex and may encode either subunits of the enzyme or components required for its assembly and targeting. Collectively, these findings implicate a critical role for acidification in vacuolar protein sorting and zymogen activation in yeast, and suggest that components of the yeast vacuolar acidification system may be identified by examining mutants defective in sorting of vacuolar proteins.
Subjects:
[+]
Adenosine Triphosphatases Blotting, Western Cell Compartmentation Fungal Proteins Hydrogen-Ion Concentration Lysosomes Mutation Quinacrine Saccharomyces Cerevisiae Vacuoles
Source:
J Cell Biol. 109(1):93-100.
Pubmed ID:
2526133
Pubmed Central ID:
PMC2115461
Document Type:
Journal Article
Funding:
PHS 32448/PH/PHPPO CDC HHS/United States
Collection(s):
CDC Public Access
Main Document Checksum:
[+]
urn:sha256:58ca98a3cfbfd622954f6e95b4c1f1cc67c1d90275b5fd72352bffc81f690e69
Download URL:
https://stacks.cdc.gov/view/cdc/30788/cdc_30788_DS1.pdf
File Type:

Supporting Files

• 	jc109193.nxml	txt
  	license.txt	txt

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