Identification of myo-inositol-3-phosphate synthase isoforms: characterization, expression, and putative role of a 16-kDa gamma(c) isoform.

ABSTRACT: Myo-inositol is an important constituent of membrane phospholipids and is a precursor for the phosphoinositide signaling pathway. It is synthesized from glucose 6-phosphate by myo-inositol-3-phosphate synthase (IP synthase), a homotrimer composed of a 68-kDa polypeptide in most mammalian tissues. It is a putative target for mood-stabilizing drugs such as lithium and valproate. Here, we show that the rat gene (Isyna1) encoding this enzyme generates a number of alternatively spliced transcripts in addition to the fully spliced form that encodes the 68-kDa subunit (the alpha isoform). Specifically, we identify a small 16-kDa subunit (the gamma(c) isoform) derived by an intron retention mechanism and provide evidence for its existence in rat tissues. The gamma(c) isoform is highly conserved in

SUBMITTER: Seelan RS 

PROVIDER: S-EPMC2666597 | biostudies-literature | 2009 Apr

REPOSITORIES: biostudies-literature