Cloning and expression profile of human inorganic pyrophosphatase.

We have cloned a 1.23 kb cDNA from a human heart library which encodes a 32 kDa protein that is 94% identical to bovine inorganic pyrophosphatase. The protein contains an aspartate-rich signature sequence that was previously identified in yeast and prokaryotic pyrophosphatases. Our clone detects a single band on Northern blots and is expressed at modest levels in all tissues examined. The cDNA shows linkage to markers on the long arm of chromosome 10.