A novel accessory subunit for vacuolar H(+)-ATPase from chromaffin granules.

摘要: Three subunits, Ac115, Ac39, and the proteolipid, were positively identified in membrane sectors of V-ATPases from different sources. We searched for organelle-specific protein purified preparations V-ATPase bovine chromaffin granules. A diffused band at a position about 45 kDa was SDS-polyacrylamide gels above preparation. Following digestion with endopeptidase Glu-C (V-8), polypeptide 10 isolated subjected to amino acid sequencing. Hence, cDNA encoding Ac45 cloned adrenal medulla library. The sequence contains an open reading frame 468 acids calculated molecular mass 51,786 daltons. potential signal comprised first 35 transmembrane domain C terminus identified. There exist seven glycosylation sites between aforementioned motifs. Experiments specific antibody against demonstrated that it is copurifying Immunological cross-reactivity observed kidney microsomes but not plasma membranes epithelial cells. Cell-free expression synthetic mRNA produced single 50 on SDS gels. Upon inclusion dog pancreas reaction mixture, slow migrating sensitive peptide:N-glycosidase F observed.