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Urotensin II.svg
ChemSpider 24646295
Jmol-3D images Image
Molar mass 1388.6 g/mol
Infobox references
Symbol U-II
Entrez 10911
HUGO 12636
OMIM 604097
RefSeq NM_021995
UniProt O95399
Other data
Locus Chr. 1# p36

Urotensin-II (U-II) is a peptide ligand, initially isolated from the neurosecretory system of the Goby fish (Gillichthys mirabilis).[1] For many years it was thought that U-II does not exhibit significant effects in mammalian systems; a view quickly overturned when it was demonstrated that Goby U-II produces slow relaxation of mouse anococcygeus muscle, in addition to contraction of rat artery segments. In 1998, the cDNA encoding a U-II precursor was cloned in humans, unequivocally demonstrating its existence in mammalian species.The vasoconstriction it induces can cause or exacerbate hypertension, congestive heart failure, and coronary artery disease.

In fish, U-II is secreted at the back part of the spinal cord, in a neurosecretory center called uroneurapophysa, and is involved in the regulation of the renal and cardiovascular systems.[2] In mammals, it is involved in the regulation of the cardiovascular system.[3]

U-II peptide[edit]

As with other peptide ligands, U-II is synthesised from a larger precursor molecule known as Prepro-urotensin-II. Two isoforms have been identified in man of lengths 124 and 139 residues. Cleavage of either of these precursors produces identical, eleven residue, mature U-II peptides. The cyclic, C-terminal hexapeptide sequence((-CYS*-TRY-LYS-TRP-PHE-CYS*-), (*bridged CYS residues)), has been conserved through evolution from lamprey to human species, which diverged some 560 million years ago. The fact that such a strong evolutionary pressure has acted to conserve this sequence highlights its physiological importance. Indeed, this hexapeptide sequence confers biological activity.


  1. ^ Bern HA, Lederis K (September 1969). "A reference preparation for the study of active substances in the caudal neurosecretory system of teleosts". J. Endocrinol. 45 (1): Suppl:xi–xii. PMID 5347394. 
  2. ^ L. Fishelson, Zoology, renewed and corrected ed. 1984, Hakibutz Hameuchad Pub. House, Israel 1984. Vol II, p.126 (Hebrew)
  3. ^ Douglas SA, Dhanak D, Johns DG (2004). "From 'gills to pills': urotensin-II as a regulator of mammalian cardiorenal function". Trends Pharmacol. Sci. 25 (2): 76–85. doi:10.1016/j.tips.2003.12.005. PMID 15102493. 

See also[edit]