Relaxin

:"For the Miles Davis album, see "Relaxin' with the Miles Davis Quintet"."protein
Name = Relaxin 1
caption =


width =
HGNCid = 10026
Symbol = RLN1
AltSymbols =
EntrezGene = 6013
OMIM = 179730
RefSeq =
UniProt =
PDB =
ECnumber =
Chromosome = 9
Arm = q
Band = ter
LocusSupplementaryData = -q12protein
Name = Relaxin 2
caption =


width =
HGNCid = 10027
Symbol = RLN2
AltSymbols =
EntrezGene = 6019
OMIM = 179740
RefSeq =
UniProt =
PDB =
ECnumber =
Chromosome = 9
Arm = q
Band = ter
LocusSupplementaryData = -q12protein
Name = Relaxin 3
caption =


width =
HGNCid = 17135
Symbol = RLN3
AltSymbols =
EntrezGene = 117579
OMIM = 606855
RefSeq =
UniProt =
PDB =
ECnumber =
Chromosome = 19
Arm = p
Band = 13.3
LocusSupplementaryData =

Relaxin is a peptide hormone that was first described in 1926 by Frederick Hisaw. [ [http://www.time.com/time/magazine/article/0,9171,796530,00.html If a Gopher Can Do It ... - TIME ] ] [cite journal |author=Becker G, Hewitson T |title=Relaxin and renal fibrosis |journal=Kidney Int |volume=59 |issue=3 |pages=1184–5 |year=2001 |pmid=11231378 |doi=10.1046/j.1523-1755.2001.0590031184.x]

The relaxin-like peptide family belongs in the insulin superfamily and consists of 7 peptides of high structural but low sequence similarity; relaxin-1(RNL1), 2(RNL2) and 3(RNL3), and the insulin-like (INSL) peptides, INSL3, INSL4, INSL5 and INSL6. The functions of relaxin-3, INSL4, INSL5, INSL6 remain uncharacterised. [Evolution of the relaxin-like peptide family. BMC Evol Biol. 2005; 5: 14. TN Wilkinson, TP Speed, GW Tregear,RAD Bathgate.]

Production

In the female, it is produced by the corpus luteum of the ovary, the breast and, during pregnancy, also by the placenta, chorion, and decidua.

In the male it is produced in the prostate and is present in human semen. [The role of the hormone relaxin in human reproduction and pelvic girdle relaxation.Scand J Rheumatol Suppl. 1991;88:7-15. AH MacLennan.]

tructure

Structurally, relaxin is a heterodimer of two peptide chains of 24 and 29 amino acids that are linked by disulfide bridges and it appears related to insulin.

Relaxin is produced from its prohormone, “pro-relaxin”, by splitting off one additional peptide chain.

Function

Enhances sperm motility of sperm in semen.

In humans

Relaxin is produced mainly by the corpus luteum, in both pregnant and non-pregnant females, it rises to a peak within approximately 14 days of ovulation and then declines in the absence of pregnancy resulting in menstruation. During the first trimester of pregnancy levels rise and additional relaxin is produced by the decidua.

Relaxin's role or necessity in human pregnancy remains under investigation, as in humans its peak is reached during the 14 weeks of the first trimester and at delivery.

In animals

In animals relaxin widens the pubic bone and facilitates labor, it also softens the cervix (cervical ripening), and relaxes the uterine musculature. Thus, for a long time, relaxin was looked at as a pregnancy hormone. However, its significance may reach much further. Relaxin affects collagen metabolism, inhibiting collagen synthesis and enhancing its breakdown by increasing matrix metalloproteinases. [cite journal |author=Mookerjee I, Solly N, Royce S, Tregear G, Samuel C, Tang M |title=Endogenous relaxin regulates collagen deposition in an animal model of allergic airway disease |journal=Endocrinology |volume=147 |issue=2 |pages=754–61 |year=2006 |pmid=16254028 |doi=10.1210/en.2005-1006] It also enhances angiogenesis and is a potent renal vasodilator.

Receptors

Relaxin interacts with the relaxin receptor LGR7 (RXFP1) and LGR8 (RXFP2) which belong to the G-protein-coupled receptor superfamily. They contain a heptahelical transmembrane domain and a large glycosylated ectodomain, distantly related to the receptors for the glycoproteohormones, such as the LH-receptor or FSH-receptor.

Relaxin receptors have been found in the heart, smooth muscle, the connective tissue, and central and autonomous nervous system.

Disorders

Specific disorders related to relaxin have not been described, yet it has been suggested that it could be linked to scleroderma and to fibromyalgia. [cite journal |author=Van Der Westhuizen E, Summers R, Halls M, Bathgate R, Sexton P |title=Relaxin receptors--new drug targets for multiple disease states |journal=Curr Drug Targets |volume=8 |issue=1 |pages=91–104 |year=2007 |pmid=17266534 |doi=10.2174/138945007779315650]

References

External links

* [http://www.hprd.org/report?external=HprdId&accession_id=&prot_name=relaxin&gene_symbol=&function%3Alines=&ptm_type%3Alines=&localization%3Alines=&domain%3Alines=&motif%3Alines=&expression%3Alines=&prot_start=&prot_end=&mole_start=&mole_end=&disease%3Alines=&query_submit=Search Human Protein Reference Database]
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