Structural and functional characterization of neuropeptide Y in a primitive teleost, the Japanese eel (Anguilla japonica).
In the present study, the first full-length cDNA encoding Neuropeptide Y (NPY) was cloned from the brain of Japanese eel (Anguilla japonica). The open reading frame of Japanese eel NPY gene is 294 bp in length, encoding a precursor protein of 97 amino acids, which contains a 36-amino-acid mature peptide. Sequence analysis showed that the Japanese eel NPY peptide is similar to that of other species. Real-time PCR revealed that NPY in Japanese eel is mainly expressed in the brain, especially in the hypothalamus and the optic tectum thalamus. The effect of a negative energy balance on NPY gene expression was examined subsequently. The mRNA level of NPY in the hypothalamus and the optic tectum thalamus showed a pronounced increase after 4 days of food deprivation. The biological activities of Japanese eel NPY were further investigated in vivo and in vitro. Intraperitoneal injection of the NPY peptide into Japanese eel could potently elevate the expression of the mammalian gonadotropin-releasing hormone (mGnRH) in hypothalamus and the follicle-stimulating hormone beta (FSHβ), the luteinizing hormone beta (LHβ) and growth hormone (GH) in pituitary. In static incubation studies, the stimulatory effects of NPY on mGnRH expression in hypothalamic fragments and on FSHβ, LHβ and GH expression in pituitary cells were also observed. However, in vivo and in vitro studies showed that NPY exhibits an inhibitory action on the expression of thyroid-stimulating hormone beta (TSHβ) in pituitary. The results indicate that NPY is involved in the regulation of multiple physiological processes in Japanese eel.
State Key Laboratory of Biocontrol, Institute of Aquatic Economic Animals, Sun Yat-Sen University, Guangzhou 510275, China.
Shuisheng
S
Li
Liping
L
Zhao
Ling
L
Xiao
Qiongyu
Q
Liu
Wenyi
W
Zhou
Xin
X
Qi
Huapu
H
Chen
Huirong
H
Yang
Xiaochun
X
Liu
Yong
Y
Zhang
Haoran
H
Lin
D000595:Amino Acid Sequence; D000811:Anguilla / Q000235:genetics / Q000378:metabolism*; D000818:Animals; D003001:Cloning, Molecular; D018076:DNA, Complementary / Q000737:chemistry; D029941:Fish Proteins / Q000737:chemistry / Q000235:genetics / Q000502:physiology*; D005508:Food Deprivation; D015870:Gene Expression; D005786:Gene Expression Regulation; D007987:Gonadotropin-Releasing Hormone / Q000378:metabolism; D007031:Hypothalamus / Q000378:metabolism; D008969:Molecular Sequence Data; D009478:Neuropeptide Y / Q000737:chemistry / Q000235:genetics / Q000502:physiology*; D016366:Open Reading Frames; D010907:Pituitary Hormones / Q000378:metabolism; D012333:RNA, Messenger / Q000378:metabolism; D016415:Sequence Alignment; D013477:Superior Colliculi / Q000378:metabolism
D018076:DNA, Complementary; D029941:Fish Proteins; D009478:Neuropeptide Y; D010907:Pituitary Hormones; D012333:RNA, Messenger; D007987:Gonadotropin-Releasing Hormone