Novel fish hypothalamic neuropeptide.
Recently, we identified novel avian and amphibian hypothalamic neuropeptides that inhibited gonadotropin release and stimulated growth hormone release. They were characterized by a similar structure including the C-terminal LPLRF-NH2 motif. To clarify that the expression of these novel hypothalamic neuropeptides is a conserved property in vertebrates, we characterized a cDNA encoding a similar novel peptide, having LPLRF-NH2 from the goldfish brain, by a combination of 3' and 5' rapid amplification of cDNA ends (RACE). The deduced peptide precursor consisted of 197 amino acid residues, encoding three putative peptide sequences that included -LPXRF (where X is L or Q) at their C-termini. Mass spectrometric analyses revealed that a tridecapeptide (SGTGLSATLPQRF-NH2) was derived from the precursor in the brain as an endogenous ligand. Southern blotting analysis of reverse-transcriptase-mediated PCR products demonstrated a specific expression of the goldfish peptide gene in the diencephalon. In situ hybridization revealed the cellular localization of goldfish peptide mRNA in the nucleus posterioris periventricularis in the hypothalamus. Immunoreactive cell bodies were also restricted to the the nucleus posterioris periventricularis and the nervus terminalis and immunoreactive fibers were distributed in several brain regions including the nucleus lateralis tuberis pars posterioris and pituitary. Thus, the goldfish hypothalamus expresses a novel neuropeptide containing the C-terminal -LPQRF-NH2 sequence, which may possess multiple regulatory functions and act, at least partly, on the pituitary to regulate pituitary hormone release.
Sawada
Kaori
K
Laboratory of Brain Science, Faculty of Integrated Arts and Sciences, Hiroshima University, Higashi-Hiroshima, Japan.
Ukena
Kazuyoshi
K
Satake
Honoo
H
Iwakoshi
Eiko
E
Minakata
Hiroyuki
H
Tsutsui
Kazuyoshi
K
D020816:Amino Acid Motifs; D000595:Amino Acid Sequence; D000818:Animals; D001483:Base Sequence; D015152:Blotting, Northern; D015139:Blotting, Southern; D001921:Brain / Q000378:metabolism; D003001:Cloning, Molecular; D018076:DNA, Complementary / Q000378:metabolism; D004797:Enzyme-Linked Immunosorbent Assay; D006054:Goldfish / Q000235:genetics*; D007031:Hypothalamus / Q000378:metabolism*; D007150:Immunohistochemistry; D017403:In Situ Hybridization; D013058:Mass Spectrometry; D008969:Molecular Sequence Data; D009479:Neuropeptides / Q000737:chemistry*; D010455:Peptides / Q000737:chemistry*; D011485:Protein Binding; D017434:Protein Structure, Tertiary; D012333:RNA, Messenger / Q000378:metabolism; D020133:Reverse Transcriptase Polymerase Chain Reaction
D018076:DNA, Complementary; D009479:Neuropeptides; D010455:Peptides; D012333:RNA, Messenger