ATP7A

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ATPase, Cu++ transporting, alpha polypeptide
Protein ATP7A PDB 1aw0.png
PDB rendering based on 1aw0.
Available structures
PDB Ortholog search: PDBe, RCSB
Identifiers
Symbols ATP7A ; DSMAX; MK; MNK; SMAX3
External IDs OMIM300011 MGI99400 HomoloGene35 GeneCards: ATP7A Gene
EC number 3.6.3.4
Orthologs
Species Human Mouse
Entrez 538 11977
Ensembl ENSG00000165240 ENSMUSG00000033792
UniProt Q04656 Q64430
RefSeq (mRNA) NM_000052 NM_001109757
RefSeq (protein) NP_000043 NP_001103227
Location (UCSC) Chr HG1426_PATCH:
77.17 – 77.31 Mb
Chr X:
106.03 – 106.12 Mb
PubMed search [1] [2]

Copper-transporting ATPase 1 also known as copper pump 1 or Menkes disease-associated protein is a protein that in humans is encoded by the ATP7A gene.[1]

Gene[edit]

The ATP7A gene is located on the long (q) arm of the X chromosome between positions 13.2 and 13.3, from base pair 76,972,353 to base pair 77,112,036.

Function[edit]

ATP7A is important for regulating copper levels in the body. This protein is found in most tissues, but it is absent from the liver. In the small intestine, the ATP7A protein helps control the absorption of copper from food. In other organs and tissues, the ATP7A protein has a dual role and shuttles between two locations within the cell. The protein normally resides in a cell structure called the Golgi apparatus, which modifies and transports newly produced enzymes and other proteins. Here, the ATP7A protein supplies copper to certain enzymes that are critical for the structure and function of bone, skin, hair, blood vessels, and the nervous system. If copper levels in the cell environment are elevated, however, the ATP7A protein moves to the cell membrane and eliminates excess copper from the cell.[citation needed]

Interactions[edit]

ATP7A has been shown to interact with ATOX1[2] and GLRX.[3]

Clinical significance[edit]

Menkes syndrome is caused by mutations in the ATP7A gene. Researchers have identified more than 100 ATP7A mutations that cause Menkes syndrome and occipital horn syndrome, the milder form of Menkes syndrome. Many of these mutations delete part of the gene and are predicted to produce a shortened ATP7A protein that is unable to transport copper. Other mutations insert additional DNA building blocks (base pairs) or use the wrong building blocks, which leads to ATP7A proteins that do not function properly.

The altered proteins that result from ATP7A mutations impair the absorption of copper from food, fail to supply copper to certain enzymes, or get stuck in the cell membrane, unable to shuttle back and forth from the Golgi. As a result of the disrupted activity of the ATP7A protein, copper is poorly distributed to cells in the body. Copper accumulates in some tissues, such as the small intestine and kidneys, while the brain and other tissues have unusually low levels. The decreased supply of copper can reduce the activity of numerous copper-containing enzymes that are necessary for the structure and function of bone, skin, hair, blood vessels, and the nervous system.

References[edit]

  1. ^ Tümer Z, Møller LB, Horn N (1999). "Mutation spectrum of ATP7A, the gene defective in Menkes disease". Adv. Exp. Med. Biol. 448: 83–95. doi:10.1007/978-1-4615-4859-1_7. PMID 10079817. 
  2. ^ Larin D, Mekios C, Das K, Ross B, Yang AS, Gilliam TC (October 1999). "Characterization of the interaction between the Wilson and Menkes disease proteins and the cytoplasmic copper chaperone, HAH1p". J. Biol. Chem. 274 (40): 28497–504. doi:10.1074/jbc.274.40.28497. PMID 10497213. 
  3. ^ Lim CM, Cater MA, Mercer JF, La Fontaine S (September 2006). "Copper-dependent interaction of glutaredoxin with the N termini of the copper-ATPases (ATP7A and ATP7B) defective in Menkes and Wilson diseases". Biochem. Biophys. Res. Commun. 348 (2): 428–36. doi:10.1016/j.bbrc.2006.07.067. PMID 16884690. 


Further reading[edit]

External links[edit]