Urotensin-II

protein
Name=Urotensin-II
caption =


width =261
HGNCid = 12636
Symbol = U-II
AltSymbols =
EntrezGene = 10911
OMIM = 604097
RefSeq = NM_021995
UniProt = O95399
PDB =
ECnumber =
Chromosome = 1#
Arm = p
Band = 36
LocusSupplementaryData =

Urotensin-II (U-II) is a peptide ligand, initially isolated from the neurosecretory system of the Goby fish ("Gillichthys mirabilis") [http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?cmd=Retrieve&db=PubMed&list_uids=5347394&dopt=Abstract Bern et al. 1969] . 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 annococygeus 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.

U-II peptide

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.

See also

* Urotensin-II receptor