title: Effects of crustacean hyperglycemic hormone (CHH) on the transcript expression of carbohydrate metabolism-related enzyme genes in the kuruma prawn, Marsupenaeus japonicus.
abstract: Crustacean hyperglycemic hormone (CHH), a member of a neuropeptide family present only in arthropods, plays a pivotal role in the modulation of hemolymph glucose levels, molting, reproduction, and the stress response. Although it has been determined that hepatopancreas and muscle are the major tissues in which CHH regulates hyperglycemic activity, the molecular mechanism by which CHH regulates carbohydrate metabolism remains unclear. In this study, we analyzed the mRNA expression levels of enzymes involved in glycogen metabolism and gluconeogenesis in order to determine how CHH regulates hemolymph glucose levels. We first cloned cDNAs encoding four carbohydrate metabolism-related enzymes from the kuruma prawn, Marsupenaeus japonicus, glycogen phosphorylase (MjGP), glycogen synthase (MjGS), fructose 1,6-bisphosphatase (MjFBPase), and phosphoenolpyruvate carboxykinase (MjPEPCK). RT-PCR analysis showed that eyestalk ablation remarkably decreased MjGP and increased MjGS transcript levels in the hepatopancreas, but not in muscle. Considering the fact that various eyestalk factors, including MIH, are removed by eyestalk ablation, these results indicate that after eyestalk ablation the metabolic state proceeds towards glycogen accumulation in the specific tissues related to molting. In contrast, MjFBPase and MjPEPCK transcript levels were not significantly changed by eyestalk ablation, indicating that CHH and other eyestalk-derived factors might not induce gluconeogenesis. Quantitative real-time PCR analysis showed that exposure of hepatopancreas to recombinant CHH significantly changed the expression levels of MjGP and MjGS, but not MjFBPase and MjPEPCK. Collectively, these results indicate that CHH is involved in glycogen metabolism in hepatopancreas.
authors: Department of Applied Biological Chemistry, Graduate School of Agricultural and Life Sciences, The University of Tokyo, Tokyo, Japan.
authors: Chiaki
authors: C
authors: Nagai
authors: Shinji
authors: S
authors: Nagata
authors: Hiromichi
authors: H
authors: Nagasawa
mesh_terms: D000595:Amino Acid Sequence; D000818:Animals; D060829:Arthropod Proteins; D050260:Carbohydrate Metabolism / Q000187:drug effects* / Q000235:genetics; D003001:Cloning, Molecular; D004798:Enzymes / Q000235:genetics* / Q000378:metabolism; D005786:Gene Expression Regulation / Q000187:drug effects; D005796:Genes; D006003:Glycogen / Q000378:metabolism; D043143:Hepatopancreas / Q000187:drug effects / Q000378:metabolism; D007447:Invertebrate Hormones; D008954:Models, Biological; D008969:Molecular Sequence Data; D009419:Nerve Tissue Proteins / Q000494:pharmacology*; D033561:Penaeidae / Q000187:drug effects / Q000235:genetics* / Q000378:metabolism*; D012333:RNA, Messenger / Q000235:genetics / Q000378:metabolism; D017386:Sequence Homology, Amino Acid
chemical_list: D060829:Arthropod Proteins; D004798:Enzymes; D007447:Invertebrate Hormones; D009419:Nerve Tissue Proteins; D012333:RNA, Messenger; C015947:hyperglycemic hormone, crustacean; D006003:Glycogen