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.