LETM1

Leucine zipper-EF-hand containing transmembrane protein 1 is a protein that in humans is encoded by the "LETM1" gene.
Structure.
The LETM1 protein has a transmembrane domain and a casein kinase 2 and protein kinase C phosphorylation site. The LETM1 gene is expressed in the mitochondria of many eukaryotes indicating that this is a conserved mitochondrial protein.
Function.
LETM1 is a eukaryotic protein that is expressed in the inner membrane of mitochondria. Experiments performed with human cells have been interpreted to indicate that it functions as a component of a Ca2+/H+ antiporter. Experimental results with yeast cells have been interpreted as suggesting that LETM1 functions as a component of a K+/H+ antiporter. The "Drosophila melanogaster" LETM1 protein has been shown to functionally substitute for the K+/H+ antiporter function in yeast cells.
Clinical significance.
Deletion of LETM1 is thought to be involved in the development of Wolf–Hirschhorn syndrome in humans.