Alternative translation initiation gives rise to two isoforms of Orai1 with distinct plasma membrane mobilities.

ABSTRACT: Store-operated calcium entry is an almost ubiquitous signaling pathway in eukaryotic cells. The plasma membrane store-operated channels are comprised of subunits of the recently discovered Orai proteins, the major one being Orai1.We have discovered that native Orai1, as well as expressed Orai1, exists in two forms in similar quantities: a longer form (Orai1α) of approximately 33 kDa, and a shorter form (Orai1β) of approximately 23 kDa. The Orai1β form arises from alternative translation initiation from a methionine at position 64, and possibly also 71, in the longer Orai1α form. In the sequence upstream of the initiation site of Orai1β, there is a poly-arginine sequence previously suggested to be involved in interaction of Orai1 with plasma membrane phosphatidylinositol-4,5-bisphosphate. T

SUBMITTER: Fukushima M 

PROVIDER: S-EPMC3516440 | biostudies-literature | 2012 Sep

REPOSITORIES: biostudies-literature