An extended nomenclature for mammalian V-ATPase subunit genes and splice variants.

Kevin C Miranda,Fiona E Karet,Dennis Brown

doi:10.1371/journal.pone.0009531

Abstract

The vacuolar-type H+-ATPase (V-ATPase) is a multisubunit proton pump that is involved in both intra- and extracellular acidification processes throughout the body. Multiple homologs and splice variants of V-ATPase subunits are thought to explain its varied spatial and temporal expression pattern in different cell types. Recently subunit nomenclature was standardized with a total of 22 subunit variants identified. However this standardization did not accommodate the existence of splice variants and is therefore incomplete. Thus, we propose here an extension of subunit nomenclature along with a literature and sequence database scan for additional V-ATPase subunits. An additional 17 variants were pulled from a literature search while 4 uncharacterized potential subunit variants were found in sequence databases. These findings have been integrated with the current V-ATPase knowledge base to create a new V-ATPase subunit catalogue. It is envisioned this catalogue will form a new platform on which future studies into tissue- and organelle-specific V-ATPase expression, localization and function can be based.

Highlights

The vacuolar-type H+-ATPase (V-ATPase) is a proton pump found in all nucleated cells of the body
We suggest augmenting the naming policy to allow for the differentiation of splice variants
In accordance with HUGO Gene Nomenclature Committee (HGNC) specifications, we propose the addition of a ‘‘v[1..x]’’ suffix to the relevant gene symbols, and ‘‘i[1..x]’’ to the predicted proteins

Summary

Introduction

The vacuolar-type H+-ATPase (V-ATPase) is a proton pump found in all nucleated cells of the body. The V-ATPase is functionally important at the plasma membrane of specialized cell types in certain tissues. The V-ATPase is a large (800 kDa) and complex molecular motor It is made up of at least 13 individual components/protein subunits organized into two functional domains: V0 and V1 [1,4,11,12]. Discovery of V-ATPase homologs and splice variants has largely been subunit focused and experimentally based. This method has proven successful as demonstrated by the large number of identified variants. This fragmented discovery process led to a fragmented naming system which was recently

41 ATP6V1H ATP6V1Hv1

Results and Discussion

Materials and Methods