SERCA
| SERCA | ||
|---|---|---|
| Mass / length primary structure | 1000-1043 amino acids | |
| Secondary to quaternary structure | multipass membrane protein | |
| Cofactor | magnesium | |
| Isoforms | 1neonatal, 1adult, 2A, 2B, 3A, 3B, 3C, 3D, 3E, 3F | |
| Identifier | ||
| Gene name (s) | ATP2A1 , ATP2A2 , ATP2A3 | |
| Transporter classification | ||
| TCDB | 3.A.3.2.7 | |
| designation | P-ATPase | |
| Enzyme classification | ||
| EC, category | 3.6.3.8 , ATPase | |
| Response type | hydrolysis | |
| Substrate | ATP + H 2 O + Ca 2+ (out) | |
| Products | ADP + phosphate + Ca 2+ (in) | |
| Occurrence | ||
| Parent taxon | Chordates | |
SERCA (abbreviation for. English S arcoplasmic / e ndoplasmic r eticulum c alcium A TPase , German calcium ATPase of the sarcoplasmic and endoplasmic reticulum ) are called proteins in the membrane of certain cell components, the calcium ion pumps with consumption of ATP from the cytosol into the sarcoplasmic reticulum . They belong to the calcium pumps and occur in all chordates . Three genes code for ten SERCA isoforms in humans, with isoforms 1A and 2A only occurring in muscles, where they can make up up to 90 percent of the protein. Mutations in the genes can lead to diseases such as Brody's disease , acrokeratosis veruciformis (Hopf's disease), and Darier's disease . Incorrect reading of ATP2A1 due to mutations in the gene of the DMPK kinase results in a defective SERCA1 isoform, which in turn is the cause of myotonic dystrophy type 1 .
function
Calcium ions are released into the sarcoplasm to coordinate the trillion myosin motors in muscle movement . The contraction does not stop until the calcium is pumped back into the sarcoplasmic reticulum . For this purpose, SERCA transporters are installed in the membrane of these compartments. But calcium is also used as a second messenger in other tissues, just not as concentrated as in muscles.
The transport equation is:
ATP + H 2 O + H + (sr / er) + Ca 2+ (cyt) ⇒ ADP + phosphate + Ca 2+ (sr / er) + H + (cyt)
It is therefore a Ca 2+ : H + antiport.
Outside of calcium transport, SERCA1 appears to generate heat in certain adipocytes . The amount of heat generated in the muscle can be measured.
regulation
The expression of SERCA1 in certain muscle cells is dependent on thyroid hormones in rabbits.
See also
Individual evidence
- ↑ UniProt P16615 , UniProt O14983 , UniProt Q93084
- ↑ Hino S, Kondo S, Sekiya H, et al : Molecular mechanisms responsible for aberrant splicing of SERCA1 in myotonic dystrophy type 1 . In: Hum. Mol. Genet. . 16, No. 23, December 2007, pp. 2834-43. doi : 10.1093 / hmg / ddm239 . PMID 17728322 .
- ↑ TCDB: 3.A.3.2.7
- ↑ Karjalainen EL, Hauser K, Barth A: Proton paths in the sarcoplasmic reticulum Ca (2+) -ATPase . In: Biochim. Biophys. Acta . 1767, No. 11, November 2007, pp. 1310-8. doi : 10.1016 / j.bbabio.2007.07.010 . PMID 17904096 .
- ↑ de Meis L, Oliveira GM, Arruda AP, Santos R, Costa RM, Benchimol M: The thermogenic activity of rat brown adipose tissue and rabbit white muscle Ca2 + -ATPase . In: IUBMB Life . 57, No. 4-5, 2005, pp. 337-45. doi : 10.1080 / 15216540500092534 . PMID 16036618 .
- ↑ Arruda AP, Nigro M, Oliveira GM, de Meis L: Thermogenic activity of Ca2 + -ATPase from skeletal muscle heavy sarcoplasmic reticulum: the role of ryanodine Ca2 + channel . In: Biochim. Biophys. Acta . 1768, No. 6, June 2007, pp. 1498-505. doi : 10.1016 / j.bbamem.2007.03.016 . PMID 17466935 .
- ↑ Arruda AP, Oliveira GM, Carvalho DP, De Meis L: Thyroid hormones differentially regulate the distribution of rabbit skeletal muscle Ca (2 +) - ATPase (SERCA) isoforms in light and heavy sarcoplasmic reticulum . In: Mol. Membr. Biol . 22, No. 6, 2005, pp. 529-37. doi : 10.1080 / 09687860500412257 . PMID 16373324 .