We have identified a cDNA encoding a novel putative neuron-specific isoform of vacuolar proton-translocating ATPase (V-ATPase), NM9.2, from rat and mouse. Sequence analysis revealed that NM9.2 conserved similar characteristic amino acid sequences with 60-70% identity to M9.2 previously isolated from V-ATPase in chromaffin granules. Using Northern blot analysis, NM9.2 mRNA was specifically detected in the brain, whereas M9.2 mRNA was widely expressed in various tissues. In situ hybridization showed that NM9.2 gene expression was restricted mainly to neuronal cells and consistent with that of the a1/Ac116 subunit of V-ATPase. NM9.2 is a putative neuronal isoform of the 9.2 kDa subunit in V-ATPase.
Copyright 2003 Lippincott Williams & Wilkins