The putative 116 kDa osteoclast specific vacuolar proton pump subunit has ubiquitous tissue distribution.

The pharmacological profile of the osteoclast proton pump has been demonstrated to be unique and to be the most active of all acid transport systems thus far studied. The recently reported putative 116 kDa osteoclast specific vacuolar proton pump subunit could possibly explain the unique nature of this proton pump. Here, we demonstrate however, that the osteoclast 116 kDa subunit is not osteoclast specific but has ubiquitous expression in human tissue.