Peptidomic identification and biological validation of neuroendocrine regulatory peptide-1 and -2.
Recent advances in peptidomics have enabled the identification of previously uncharacterized peptides. However, sequence information alone does not allow us to identify candidates for bioactive peptides. To increase an opportunity to discover bioactive peptides, we have focused on C-terminal amidation, a post-translational modification shared by many bioactive peptides. We analyzed peptides secreted from human medullary thyroid carcinoma TT cells that produce amidated peptides, and we identified two novel amidated peptides, designated neuroendocrine regulatory peptide (NERP)-1 and NERP-2. NERPs are derived from distinct regions of the neurosecretory protein that was originally identified as a product of a nerve growth factor-responsive gene in PC12 cells. Mass spectrometric analysis of the immunoprecipitate using specific antibodies as well as reversed phase-high performance liquid chromatography coupled with radioimmunoassay analysis of brain extract demonstrated the endogenous presence of NERP-1 and NERP-2 in the rat. NERPs are abundant in the paraventricular and supraoptic nuclei of the rat hypothalamus and colocalized frequently with vasopressin but rarely with oxytocin. NERPs dose-dependently suppressed vasopressin release induced by intracerebroventricular injection of hypertonic NaCl or angiotensin II in vivo. NERPs also suppressed basal and angiotensin II-induced vasopressin secretion from hypothalamic explants in vitro. Bioactivity of NERPs required C-terminal amidation. Anti-NERP IgGs canceled plasma vasopressin reduction in response to water loading, indicating that NERPs could be potent endogenous suppressors of vasopressin release. These findings suggest that NERPs are novel modulators in body fluid homeostasis.
Yamaguchi
Hideki
H
Division of Neurology, Respirology, Endocrinology, and Metabolism, Department of Internal Medicine, Miyazaki Medical College, University of Miyazaki, Kihara, Kiyotake, Miyazaki 889-1692, Japan.
Sasaki
Kazuki
K
Satomi
Yoshinori
Y
Shimbara
Takuya
T
Kageyama
Haruaki
H
Mondal
Muhtashan S
MS
Toshinai
Koji
K
Date
Yukari
Y
González
Luis J
LJ
Shioda
Seiji
S
Takao
Toshifumi
T
Nakazato
Masamitsu
M
Minamino
Naoto
N
D000804:Angiotensin II / Q000494:pharmacology; D000818:Animals; D000906:Antibodies / Q000494:pharmacology; D001923:Brain Chemistry / Q000187:drug effects*; D004305:Dose-Response Relationship, Drug; D006801:Humans; D008297:Male; D009419:Nerve Tissue Proteins / Q000037:antagonists & inhibitors / Q000235:genetics / Q000302:isolation & purification / Q000378:metabolism / Q000494:pharmacology*; D010121:Oxytocin / Q000378:metabolism; D016716:PC12 Cells; D010286:Paraventricular Hypothalamic Nucleus / Q000737:chemistry / Q000378:metabolism; D010455:Peptides / Q000037:antagonists & inhibitors / Q000235:genetics / Q000302:isolation & purification / Q000378:metabolism / Q000494:pharmacology*; D011499:Protein Processing, Post-Translational; D051381:Rats; D017208:Rats, Wistar; D012462:Saline Solution, Hypertonic; D013495:Supraoptic Nucleus / Q000737:chemistry / Q000378:metabolism; D014662:Vasoconstrictor Agents / Q000494:pharmacology; D014667:Vasopressins / Q000378:metabolism; D014867:Water / Q000378:metabolism; D014882:Water-Electrolyte Balance / Q000187:drug effects* / Q000502:physiology
D000906:Antibodies; D009419:Nerve Tissue Proteins; D010455:Peptides; D012462:Saline Solution, Hypertonic; D014662:Vasoconstrictor Agents; C523893:neuroendocrine regulatory peptide-1, human; C523894:neuroendocrine regulatory peptide-1, rat; C523895:neuroendocrine regulatory peptide-2, human; C523896:neuroendocrine regulatory peptide-2, rat; D014867:Water; D014667:Vasopressins; D000804:Angiotensin II; D010121:Oxytocin