LETM1

Leucine zipper-EF-hand containing transmembrane protein 1 is a protein that in humans is encoded by the LETM1 gene.^[5]

LETM1
Identifiers
Aliases	LETM1, leucine zipper and EF-hand containing transmembrane protein 1, SLC55A1
External IDs	OMIM: 604407; MGI: 1932557; HomoloGene: 56320; GeneCards: LETM1; OMA:LETM1 - orthologs
Gene location (Human) Chr. Chromosome 4 (human)[1] Band 4p16.3 Start 1,811,479 bp[1] End 1,856,156 bp[1]
Gene location (Mouse) Chr. Chromosome 5 (mouse)[2] Band 5|5 B2 Start 33,897,017 bp[2] End 33,940,161 bp[2]
RNA expression pattern Bgee Human Mouse (ortholog) Top expressed in mucosa of transverse colon sural nerve buccal mucosa cell apex of heart epithelium of nasopharynx stromal cell of endometrium right adrenal gland right adrenal cortex right lobe of thyroid gland left adrenal cortex Top expressed in right kidney brown adipose tissue proximal tubule dentate gyrus of hippocampal formation granule cell jejunum myocardium of ventricle human kidney intestinal villus muscle of thigh duodenum More reference expression data BioGPS n/a
Gene ontology Molecular function ribosome binding calcium ion binding protein binding metal ion binding calcium:proton antiporter activity antiporter activity Cellular component integral component of membrane mitochondrial inner membrane membrane mitochondrion Biological process cristae formation cellular metal ion homeostasis mitochondrial calcium ion transmembrane transport protein hexamerization protein homooligomerization mitochondrial calcium ion homeostasis calcium export from the mitochondrion ion transport calcium ion transport negative regulation of mitochondrial calcium ion concentration regulation of cellular hyperosmotic salinity response Sources:Amigo / QuickGO
Orthologs Species Human Mouse Entrez 3954 56384 Ensembl ENSG00000168924 ENSMUSG00000005299 UniProt O95202 Q9Z2I0 RefSeq (mRNA) NM_012318 NM_019694 RefSeq (protein) NP_036450 NP_062668 Location (UCSC) Chr 4: 1.81 – 1.86 Mb Chr 5: 33.9 – 33.94 Mb PubMed search [3] [4]
Wikidata
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Structure

The LETM1 protein has a transmembrane domain and a casein kinase 2 and protein kinase C phosphorylation site.^[6] The LETM1 gene is expressed in the mitochondria of many eukaryotes indicating that this is a conserved mitochondrial protein.^[7]

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.^[8] Experimental results with yeast cells have been interpreted as suggesting that LETM1 functions as a component of a K⁺/H⁺ antiporter.^[9] The Drosophila melanogaster LETM1 protein has been shown to functionally substitute for the K⁺/H⁺ antiporter function in yeast cells.^[10]

Clinical significance

Deletion of LETM1 is thought to be involved in the development of Wolf–Hirschhorn syndrome in humans.^[6]

See also

• LETM1-like protein family