Alternative splicing generates a second isoform of the catalytic A subunit of the vacuolar H(+)-ATPase.
We have identified a second isoform of the catalytic A subunit of the vacuolar H+ pump in chicken osteoclasts. In this isoform (A2) a 72-bp cassette replaces a 90-bp cassette present in the classical A1 isoform. The A1-specific cassette encodes a region of the protein that contains one of the three ATP-binding consensus sequences (the P-loop) identified in this polypeptide, as well as the pharmacologically relevant Cys254. In contrast, the A2-specific cassette does not contain any of these features. These two isoforms, which appear to be ubiquitously expressed, are encoded by a single gene and are generated by alternative splicing of two mutually exclusive exons. The alternative RNA processing involves the recognition of a single site, the boundary between the A2- and A1-specific exons, as either acceptor (in A1) or donor (in A2) splice site.
Hernando
N
N
Department of Cell Biology, Yale University School of Medicine, New Haven, CT 06510, USA.
Bartkiewicz
M
M
Collin-Osdoby
P
P
Osdoby
P
P
Baron
R
R
D000255:Adenosine Triphosphate / Q000378:metabolism; D017398:Alternative Splicing; D000595:Amino Acid Sequence; D000818:Animals; D001483:Base Sequence; D001665:Binding Sites; D015139:Blotting, Southern; D002645:Chickens; D016384:Consensus Sequence; D017931:DNA Primers; D018076:DNA, Complementary / Q000378:metabolism; D005260:Female; D015870:Gene Expression; D015723:Gene Library; D007527:Isoenzymes / Q000096:biosynthesis*; D046911:Macromolecular Substances; D008969:Molecular Sequence Data; D016254:Mutagenesis, Insertional; D009928:Organ Specificity; D010010:Osteoclasts / Q000201:enzymology; D016133:Polymerase Chain Reaction; D006180:Proton-Translocating ATPases / Q000096:biosynthesis*; D017386:Sequence Homology, Amino Acid; D012689:Sequence Homology, Nucleic Acid
D017931:DNA Primers; D018076:DNA, Complementary; D007527:Isoenzymes; D046911:Macromolecular Substances; D000255:Adenosine Triphosphate; D006180:Proton-Translocating ATPases