Tachykinin peptides
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Tachykinin peptides are one of the largest family of neuropeptides, found from amphibians to mammals. The tachykinin family is characterized by a common C-terminal sequence, Phe-X-Gly-Leu-Met-NH2, where X is either an Aromatic or an Aliphatic amino acid.
The most notable tachykinin is Substance P.
[edit] Receptors
- See main article at tachykinin receptor
There are three known mammalian tachykinin receptors termed NK1, NK2 and NK3. All are members of the 7 transmembrane g protein-coupled family of receptors and induce the activation of phospholipase C, producing inositol triphosphate. NK1, NK2 and NK3 selectively bind to substance P, neurokinin A and neurokinin B, respectively. Whilst the receptors are not specific to any individual tachykinin, they do have differing affinity for the tachykinins:
- NK1: SP>NKA>NKB;
- NK2: NKA>NKB>SP;
- NK3: NKB>NKA>SP.
Antagonists of neurokinin-1 (NK(1)) receptors, through which substance P acts, have been proposed to belong to a new class of antidepressants
[edit] External links
Angiotensin - Bombesin - Bradykinin - Calcitonin - Calcitonin gene-related peptide - Carnosine - Cholecystokinin - Delta sleep-inducing peptide - FMRFamide - Galanin - Gastric inhibitory polypeptide - Gastrin releasing peptide - Gastrin - Motilin - Neuromedin B - Neuropeptide Y - Neurophysins - Neurotensin - Opioid peptide - Pancreatic polypeptide - Pituitary adenylate cyclase activating peptide - Secretin - Tachykinins - Vasoactive intestinal peptide - Vasopressin
Hypothalamic: Somatostatin - CRH - GnRH - GHRH - Orexins - TRH - POMC (ACTH, MSH, Lipotropin)
Kininogen (MHWK, LHWK) - Bradykinin (Kallidin) - Tachykinin - Urotensin 2
