Leucine Zipper EF-Hand Containing Transmembrane Protein 1 (LETM1)

LETM1 encodes a protein that is localized to the inner mitochondrial membrane. The protein functions to maintain the mitochondrial tubular shapes and is required for normal mitochondrial morphology and cellular viability.

The deduced 739-amino acid protein is 83.8% identical to mouse Letm1 and contains 2 EF-hand calcium-binding sites, a transmembrane domain, a leucine zipper motif, several coiled-coil domains, and phosphorylation sites. Northern blot analysis showed that LETM1 was expressed in all adult and fetal human tissues tested. The authors identified 4 different transcript sizes, possibly resulting from alternative polyadenylation. RNA in situ hybridization showed that Letm1 expression was ubiquitous in mouse embryo sections at day 13.5.