The novel protein Ccz1p required for vacuolar assembly in Saccharomyces cerevisiae functions in the same transport pathway as Ypt7p.
CCZ1 was previously identified by the sensitivity of ccz1(delta) mutants to high concentrations of Caffeine and the divalent ions Ca(2+ )and Zn(2+). In this paper we show that deletion of CCZ1 leads to aberrant vacuole morphology, similar to the one reported for the family of vacuolar protein sorting (vps) mutants of class B. The ccz1(&Dgr;) cells display severe vacuolar protein sorting defects for both the soluble carboxipeptidase Y and the membrane-bound alkaline phosphatase, which are delivered to the vacuole by distinct routes. Ccz1p is a membranous protein and the vast majority of Ccz1p resides in late endosomes. These results, along with a functional linkage found between the CCZ1 and YPT7 genes, indicate that the site of Ccz1p function is at the last step of fusion of multiple transport intermediates with the vacuole.
Kucharczyk
R
R
Institute of Biochemistry and Biophysics, Polish Academy of Sciences, Pawin'skiego 5A, Poland.
Dupre
S
S
Avaro
S
S
Haguenauer-Tsapis
R
R
Słonimski
P P
PP
Rytka
J
J
D018528:ATP-Binding Cassette Transporters / Q000235:genetics / Q000378:metabolism; D002118:Calcium / Q000378:metabolism; D000252:Calcium-Transporting ATPases / Q000235:genetics / Q000378:metabolism; D002352:Carrier Proteins / Q000032:analysis / Q000378:metabolism; D027682:Cation Transport Proteins; D002451:Cell Compartmentation / Q000502:physiology; D004705:Endocytosis / Q000502:physiology; D005656:Fungal Proteins / Q000032:analysis / Q000235:genetics* / Q000378:metabolism*; D017353:Gene Deletion; D018628:Gene Dosage; D008565:Membrane Proteins / Q000235:genetics / Q000378:metabolism; D018832:Molecular Chaperones; D016296:Mutagenesis / Q000502:physiology; D010641:Phenotype; D053499:Plasma Membrane Calcium-Transporting ATPases; D010957:Plasmids; D011956:Receptors, Cell Surface / Q000235:genetics; D012441:Saccharomyces cerevisiae / Q000166:cytology / Q000235:genetics / Q000378:metabolism*; D029701:Saccharomyces cerevisiae Proteins; D017923:Sodium-Hydrogen Exchangers; D014617:Vacuoles / Q000737:chemistry / Q000378:metabolism*; D033921:Vesicular Transport Proteins; D015032:Zinc / Q000378:metabolism; D020691:rab GTP-Binding Proteins / Q000235:genetics / Q000378:metabolism*
D018528:ATP-Binding Cassette Transporters; D002352:Carrier Proteins; D027682:Cation Transport Proteins; D005656:Fungal Proteins; D008565:Membrane Proteins; D018832:Molecular Chaperones; C492183:NHX1 protein, S cerevisiae; C087335:PEP1 protein, S cerevisiae; C085484:PMC1 protein, S cerevisiae; D011956:Receptors, Cell Surface; C101767:SSC1 protein, S cerevisiae; D029701:Saccharomyces cerevisiae Proteins; D017923:Sodium-Hydrogen Exchangers; D033921:Vesicular Transport Proteins; C088843:ZRC1 protein, S cerevisiae; C079005:YPT7 protein, S cerevisiae; D053499:Plasma Membrane Calcium-Transporting ATPases; D020691:rab GTP-Binding Proteins; D000252:Calcium-Transporting ATPases; D015032:Zinc; D002118:Calcium