gamma-Preprotachykinin-(72-92)-peptide amide: an endogenous preprotachykinin I gene-derived peptide that preferentially binds to neurokinin-2 receptors.
The presence of N-terminally extended forms of neurokinin A has recently been reported in the mammalian brain. Among them, gamma-preprotachykinin-(72-92)-peptide amide [gamma-PPT-(72-92)-NH2], a peptide derived by posttranslational processing of gamma-preprotachykinin, is most prominent. We report here that this peptide most likely acts on neurokinin-2 receptor sites since neurokinin A (a putative neurokinin-2 agonist) and gamma-PPT-(72-92)-NH2 are potent competitors of 125I-labeled gamma-PPT-(72-92)-NH2 binding whereas selective neurokinin-1 and -3 agonists are not. Moreover, the distribution of 125I-labeled gamma-PPT-(72-92)-NH2 and 125I-labeled neurokinin A binding sites are very similar in rat brain. On the other hand, 125I-labeled Bolton-Hunter-substance P (a neurokinin-1 ligand) and 125I-labeled Bolton-Hunter-eledoisin (a neurokinin-3 ligand) binding sites are differentially located in this tissue. Thus, it appears that gamma-PPT-(72-92)-NH2 binds to neurokinin-2 receptors and should be considered as a putative endogenous ligand for this receptor class.
Douglas Hospital Research Centre, McGill University, Verdun, Canada.
T V
TV
Dam
Y
Y
Takeda
J E
JE
Krause
E
E
Escher
R
R
Quirion
D000818:Animals; D001345:Autoradiography; D001667:Binding, Competitive; D001921:Brain / Q000378:metabolism*; D002462:Cell Membrane / Q000378:metabolism; D007457:Iodine Radioisotopes; D007700:Kinetics; D008297:Male; D009928:Organ Specificity; D010446:Peptide Fragments / Q000138:chemical synthesis / Q000378:metabolism*; D011869:Radioligand Assay; D051381:Rats; D011919:Rats, Inbred Strains; D018041:Receptors, Neurokinin-2; D017981:Receptors, Neurotransmitter / Q000378:metabolism*; D013373:Substance P / Q000378:metabolism*; D015320:Tachykinins / Q000138:chemical synthesis / Q000378:metabolism*
D007457:Iodine Radioisotopes; D010446:Peptide Fragments; D018041:Receptors, Neurokinin-2; D017981:Receptors, Neurotransmitter; D015320:Tachykinins; C059905:tachykinin neuropeptide gamma; D013373:Substance P