Alternative splicing generates a second isoform of the catalytic A subunit of the vacuolar H(+)-ATPase.

AUTOR(ES)

Hernando, N

RESUMO

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.

Documentos Relacionados

• Mutational analysis of yeast vacuolar H(+)-ATPase.
• A bovine cDNA and a yeast gene (VMA8) encoding the subunit D of the vacuolar H(+)-ATPase.
• Selectively amplified expression of an isoform of the vacuolar H(+)-ATPase 56-kilodalton subunit in renal intercalated cells.
• Vacuolar H(+)-ATPase 69-kilodalton catalytic subunit cDNA from developing cotton (Gossypium hirsutum) ovules.
• Sequence of a cDNA from Drosophila coding for the 16 kD proteolipid component of the vacuolar H(+)-ATPase.