title: Determination of Ghrelin Structure in the Barfin Flounder (Verasper moseri) and Involvement of Ingested Fatty Acids in Ghrelin Acylation.
abstract: Ghrelin is a peptide hormone that is acylated with a fatty acid, usually n-octanoic acid, at the third amino acid (aa) residue (usually a serine or threonine), and this acylation is known to be essential for ghrelin activity not only in mammals but also in non-mammals, such as fish. However, the modification mechanisms of ghrelin modification in fish are not known. In this study, we elucidated the structure of ghrelin in a teleost, the barfin flounder (Verasper moseri), and determined whether ingested free fatty acids of various chain lengths participated in ghrelin acylation. Complementary DNA cloning revealed the barfin flounder prepro-ghrelin to be a 106-aa peptide and the mature ghrelin to be a 20-aa peptide (GSSFLSPSHKPPNKGKPPRA). However, purification of ghrelin peptides from stomach extracts demonstrated that the major form of the hormone was a 19-aa decanoylated peptide [GSS(C10:0)FLSPSHKPPNKGKPPR] missing the last alanine of the 20-aa peptide. Ingestion of feed enriched with n-heptanoic acid (C7), n-octanoic acid (C8), or n-non-anoic acid (C9) changed the modification status of the peptide: ingestion of C8 or C9 increased the amount of C8:0 or C9:0 19-aa ghrelin, respectively, but no C7:0 ghrelin was isolated after ingestion of C7. These results indicate that ingested free fatty acids are substrates for ghrelin acylation in the barfin flounder, but the types of free fatty acids utilized as substrates may be limited.
authors.affiliation: Department of Biochemistry, National Cerebral and Cardiovascular Center , Suita , Japan.
authors.forename: Hiroyuki
authors.initials: H
authors.lastname: Kaiya
authors.forename: Tadashi
authors.initials: T
authors.lastname: Andoh
authors.forename: Takashi
authors.initials: T
authors.lastname: Ichikawa
authors.forename: Noriko
authors.initials: N
authors.lastname: Amiya
authors.forename: Kouhei
authors.initials: K
authors.lastname: Matsuda
authors.forename: Kenji
authors.initials: K
authors.lastname: Kangawa
authors.forename: Mikiya
authors.initials: M
authors.lastname: Miyazato
keywords: acyl modification; barfin flounder; cDNA cloning; fatty acid; feed; ghrelin; ingestion
references.citation: Endocrinology. 2002 Sep;143(9):3454-63
references.pmid: 12193558
references.citation: Am J Physiol Endocrinol Metab. 2009 Jul;297(1):E134-41
references.pmid: 19401456
references.citation: Nat Med. 2009 Jul;15(7):741-5
references.pmid: 19503064
references.citation: Regul Pept. 2003 Mar 28;111(1-3):123-8
references.pmid: 12609759
references.citation: J Endocrinol. 2003 Mar;176(3):415-23
references.pmid: 12630926
references.citation: Vitam Horm. 2008;77:31-46
references.pmid: 17983852
references.citation: Gen Comp Endocrinol. 2005 Sep 15;143(3):201-10
references.pmid: 16111526
references.citation: Comp Biochem Physiol B Biochem Mol Biol. 2003 Jul;135(3):421-9
references.pmid: 12831762
references.citation: Int J Pept. 2010;2010:
references.pmid: 20700399
references.citation: Peptides. 2011 Nov;32(11):2155-74
references.pmid: 21600258
references.citation: Gen Comp Endocrinol. 2004 Aug;138(1):50-7
references.pmid: 15242751
references.citation: Cell. 2008 Feb 8;132(3):387-96
references.pmid: 18267071
references.citation: J Biol Chem. 2001 Nov 2;276(44):40441-8
references.pmid: 11546772
references.citation: Proc Natl Acad Sci U S A. 2008 Apr 29;105(17):6320-5
references.pmid: 18443287
references.citation: Peptides. 2011 Nov;32(11):2236-41
references.pmid: 21600256
references.citation: Peptides. 2009 Apr;30(4):758-65
references.pmid: 19150635
references.citation: Int J Pept. 2011;2011:217957
references.pmid: 21941572
references.citation: Endocrinology. 2003 Dec;144(12):5215-26
references.pmid: 12970156
references.citation: Nature. 1999 Dec 9;402(6762):656-60
references.pmid: 10604470
references.citation: Comp Biochem Physiol A Mol Integr Physiol. 2008 Feb;149(2):109-28
references.pmid: 18222718
references.citation: J Biol Chem. 2003 Jan 3;278(1):64-70
references.pmid: 12414809
references.citation: Domest Anim Endocrinol. 2007 Feb;32(2):93-105
references.pmid: 16466902
references.citation: J Mol Neurosci. 2010 Sep;42(1):99-105
references.pmid: 20437258
references.citation: Zoolog Sci. 2007 Apr;24(4):391-400
references.pmid: 17867837
references.citation: Gen Comp Endocrinol. 2007 May 1;151(3):259-68
references.pmid: 17362948
references.citation: Endocrinology. 2005 May;146(5):2255-64
references.pmid: 15677766
references.citation: Regul Pept. 2011 Feb 25;167(1):140-8
references.pmid: 21237214
references.citation: Biochem Biophys Res Commun. 2009 Aug 14;386(1):153-8
references.pmid: 19501572
references.citation: Peptides. 2011 Nov;32(11):2175-82
references.pmid: 21839128
references.citation: Biochem Biophys Res Commun. 2005 Jul 29;333(2):583-9
references.pmid: 15953586