High impact information on VPH2

• Assembly of the yeast vacuolar H+-ATPase occurs in the endoplasmic reticulum and requires a Vma12p/Vma22p assembly complex [1].
• The interaction of the Vma12p/Vma22p complex with Vph1p was transient (half-life of approximately 5 min), reflecting trafficking of this V-ATPase subunit through the ER en route to the vacuolar membrane [1].
• Biochemical analysis has revealed that Vma12p behaves as an integral membrane protein with both the N and C termini oriented toward the cytosol, and this protein immunolocalizes to the endoplasmic reticulum (ER) [2].
• These results indicate that Vma22p, along with Vma21p and Vma12p, form a set of ER proteins required for V-ATPase assembly [3].
• The association of Vma22p with ER membranes was perturbed by mutations in VMA12, a gene that encodes an ER membrane protein (Vma12p) that is also required for V-ATPase assembly [3].

Biological context of VPH2

• The VPH2 gene was isolated from a genomic DNA library by complementation of the zinc-sensitive phenotype of the mutant [4].

Associations of VPH2 with chemical compounds

• However, the Vma12 protein was not detected in the vacuolar membrane ATPase complex that had been solubilized with a zwitterionic detergent, ZW3-14, and purified by glycerol gradient centrifugation (Kane, P. M., Yamashiro, C. T., and Stevens, T. H. (1989) J. Biol. Chem. 264, 19236-19244) [5].

Other interactions of VPH2

• Subcellular fractionation and chemical cross-linking studies have revealed that Vma12p and Vma22p form a stable membrane associated complex [1].

Analytical, diagnostic and therapeutic context of VPH2

• Synthesis and targeting of the subunits of the H(+)-ATPase in the delta vma12 mutant cells were examined by Western blotting analyses of whole cell and vacuolar membrane protein extracts [5].

References