STARD7

StAR-related lipid transfer domain protein 7 (STARD7) or gestational trophoblastic tumor gene-1 (GTT1) is a lipid transporter that specifically binds and transports phosphatidylcholine between membranes.^[5]

STARD7
Identifiers
Aliases	STARD7, GTT1, StAR related lipid transfer domain containing 7, FAME2
External IDs	OMIM: 616712; MGI: 2139090; HomoloGene: 32463; GeneCards: STARD7; OMA:STARD7 - orthologs
Gene location (Human) Chr. Chromosome 2 (human)[1] Band 2q11.2 Start 96,184,859 bp[1] End 96,208,827 bp[1]
Gene location (Mouse) Chr. Chromosome 2 (mouse)[2] Band 2 F1|2 61.88 cM Start 127,112,138 bp[2] End 127,140,852 bp[2]
RNA expression pattern Bgee Human Mouse (ortholog) Top expressed in secondary oocyte internal globus pallidus deltoid muscle tibialis anterior muscle Skeletal muscle tissue of biceps brachii quadriceps femoris muscle vastus lateralis muscle optic nerve Epithelium of choroid plexus cerebellar vermis Top expressed in neural layer of retina parotid gland digastric muscle atrioventricular valve endocardial cushion ankle atrium lacrimal gland temporal muscle medial ganglionic eminence More reference expression data BioGPS n/a
Gene ontology Molecular function lipid binding phospholipid transporter activity Cellular component mitochondrion mitochondrial outer membrane Biological process phosphatidylcholine biosynthetic process phospholipid transport Sources:Amigo / QuickGO
Orthologs Species Human Mouse Entrez 56910 99138 Ensembl ENSG00000084090 ENSMUSG00000027367 UniProt Q9NQZ5 Q8R1R3 RefSeq (mRNA) NM_020151 NM_139267 NM_001385622 NM_139308 NM_001362684 RefSeq (protein) NP_064536 NP_647469 NP_001349613 Location (UCSC) Chr 2: 96.18 – 96.21 Mb Chr 2: 127.11 – 127.14 Mb PubMed search [3] [4]
Wikidata
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Function and tissue distribution

StarD7 is found in the cytosol and associated with the mitochondrion.^[5] When overproduced in the cell, mitochondrial levels of phosphatidylcholine rise.^[5] High levels of the protein are found in tumor cells compared to normal cells, suggesting a role in cell proliferation.^[6]

Structure

There are two forms of StarD7: StarD7-I and StarD7-II. The former is 295 amino acids long. StarD7-I possesses an additional 75 amino acids at its amino-terminus, which form a signaling sequence that targets it to the outer membrane of the mitochondrion.^[5]

StarD7 contains a StAR-related transfer domain (START), from which it derives its name. Moreover, the protein is a member of the predominantly phosphatidylcholine transporter subfamily of START proteins, the StarD2 subfamily. It shares 25% sequence identity with StarD2.^[5]