Chicken ghrelin: purification, cDNA cloning, and biological activity.
In this study, we report the purification, cDNA cloning, and characterization of the novel growth hormone-releasing peptide, ghrelin, in the chicken (Gallus gallus). Chicken ghrelin is composed of 26 amino acids (GSSFLSPTYKNIQQQKDTRKPTARLH) and possesses 54% sequence identity with human ghrelin. The serine residue at position 3 (Ser(3)) is conserved between the chicken and mammalian species, as its acylation by either n-octanoic or n-decanoic acid. Chicken ghrelin mRNA is predominantly expressed in the stomach, where it is present in the proventriculus but absent in the gizzard. Using RT-PCR analysis, low levels of expression were also detectable in brain, lung, and intestine. Administration of chicken ghrelin increases plasma GH levels in both rats and chicks, with a potency similar to that of rat or human ghrelin. In addition, chicken ghrelin also increases plasma corticosterone levels in growing chicks at a lower dose than in mammals. The present results indicate that the stimulatory effect of ghrelin on GH secretion is evolutionarily conserved, whereas its effect on adrenal function seems to be unique in the chicken.
Department of Biochemistry, National Cardiovascular Center Research Institute, Suita, Osaka 565-8565, Japan. kaiya@ri.ncvc.go.jp
Hiroyuki
H
Kaiya
Serge
S
Van Der Geyten
Masayasu
M
Kojima
Hiroshi
H
Hosoda
Yasuo
Y
Kitajima
Masaru
M
Matsumoto
Sofie
S
Geelissen
Veerle M
VM
Darras
Kenji
K
Kangawa
D000595:Amino Acid Sequence; D000818:Animals; D015152:Blotting, Northern; D002645:Chickens; D002851:Chromatography, High Pressure Liquid; D003001:Cloning, Molecular; D018076:DNA, Complementary / Q000235:genetics*; D015870:Gene Expression; D054439:Ghrelin; D013006:Growth Hormone / Q000097:blood; D006801:Humans; D008297:Male; D008969:Molecular Sequence Data; D036361:Peptide Hormones; D010455:Peptides / Q000737:chemistry / Q000235:genetics / Q000302:isolation & purification* / Q000494:pharmacology*; D012333:RNA, Messenger / Q000032:analysis; D051381:Rats; D017207:Rats, Sprague-Dawley; D017385:Sequence Homology; D013045:Species Specificity
D018076:DNA, Complementary; D054439:Ghrelin; D036361:Peptide Hormones; D010455:Peptides; D012333:RNA, Messenger; D013006:Growth Hormone