ALTERNATIVE SPLICING GENERATES A 2ND ISOFORM OF THE CATALYTIC A-SUBUNIT OF THE VACUOLAR H+-ATPASE

作者：HERNANDO N; BARTKIEWICZ M; COLLINOSDOBY P; OSDOBY P; BARON R

来源：Proceedings of the National Academy of Sciences of the United States of America, 1995, 92(13): 6087-6091.

DOI：10.1073/pnas.92.13.6087

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 Cys(254). 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.

• 出版日期1995-6-20