title: Two type I crustacean hyperglycemic hormone (CHH) genes in Morotoge shrimp (Pandalopsis japonica): cloning and expression of eyestalk and pericardial organ isoforms produced by alternative splicing and a novel type I CHH with predicted structure shared with type II CHH peptides.
abstract: Crustacean hyperglycemic hormone (CHH) peptide family members play critical roles in growth and reproduction in decapods. Three cDNAs encoding CHH family members (Pj-CHH1ES, Pj-CHH1PO, and Pj-CHH2) were isolated by a combination of bioinformatic analysis and conventional cloning strategies. Pj-CHH1ES and Pj-CHH1PO were products of the same gene that were generated by alternative mRNA splicing, whereas Pj-CHH2 was the product of a second gene. The Pj-CHH1 and Pj-CHH2 genes had four exons and three introns, suggesting the two genes arose from gene duplication. The three cDNAs were classified in the type I CHH subfamily, as the deduced amino acid sequences had a CHH precursor-related peptide sequence positioned between the N-terminal signal sequence and C-terminal mature peptide sequence. The Pj-CHH1ES isoform was expressed at a higher level in the eyestalk X-organ/sinus gland (XO/SG) complex and at a lower level in the gill. The Pj-CHH1PO isoform was expressed at higher levels in the XO/SG complex, brain, abdominal ganglion, and thoracic ganglion and at a lower level in the epidermis. Pj-CHH2 was expressed at a higher level in the thoracic ganglion and at a lower level in the gill. Real-time polymerase chain reaction was used to quantify the effects of eyestalk ablation on the mRNA levels of the three Pj-CHHs in the brain, thoracic ganglion, and gill. Eyestalk ablation reduced expression of Pj-CHH1ES in the brain and Pj-CHH1PO and Pj-CHH2 in the thoracic ganglion. Sequence alignment of the Pj-CHHs with CHHs from other species indicated that Pj-CHH2 had an additional alanine at position #9 of the mature peptide. Molecular modeling showed that the Pj-CHH2 mature peptide had a short alpha helix (α1) in the N-terminal region, which is characteristic of type II CHHs. This suggests that Pj-CHH2 differs in function from other type I CHHs.
authors.affiliation: Department of Marine Biology, Pukyong National University, Busan 608-737, Republic of Korea.
authors.forename: Jeong-Min
authors.initials: JM
authors.lastname: Jeon
authors.forename: Bo-Kwang
authors.initials: BK
authors.lastname: Kim
authors.forename: Jun Hyuck
authors.initials: JH
authors.lastname: Lee
authors.forename: Hak Jun
authors.initials: HJ
authors.lastname: Kim
authors.forename: Chang-Keun
authors.initials: CK
authors.lastname: Kang
authors.forename: Donald L
authors.initials: DL
authors.lastname: Mykles
authors.forename: Hyun-Woo
authors.initials: HW
authors.lastname: Kim
mesh_terms: D017398:Alternative Splicing; D000595:Amino Acid Sequence; D000818:Animals; D060829:Arthropod Proteins / Q000096:biosynthesis / Q000235:genetics*; D001483:Base Sequence; D001921:Brain / Q000378:metabolism; D003001:Cloning, Molecular; D017124:Conserved Sequence; D005123:Eye / Q000378:metabolism*; D017952:Ganglia, Invertebrate / Q000378:metabolism; D040461:Gene Components; D015870:Gene Expression; D005880:Gills / Q000378:metabolism; D007447:Invertebrate Hormones / Q000096:biosynthesis / Q000235:genetics*; D008958:Models, Molecular; D008969:Molecular Sequence Data; D009419:Nerve Tissue Proteins / Q000096:biosynthesis / Q000235:genetics*; D009490:Neurosecretory Systems / Q000378:metabolism*; D033542:Pandalidae / Q000235:genetics*; D010802:Phylogeny; D020033:Protein Isoforms / Q000096:biosynthesis / Q000235:genetics; D017433:Protein Structure, Secondary; D017434:Protein Structure, Tertiary; D017422:Sequence Analysis, DNA; D040681:Structural Homology, Protein
chemical_list: D060829:Arthropod Proteins; D007447:Invertebrate Hormones; D009419:Nerve Tissue Proteins; D020033:Protein Isoforms; C015947:hyperglycemic hormone, crustacean