title: A comparative study on the sensitivity of Cyprinus carpio muscle and liver FBPase toward AMP and calcium.
abstract: The activity of fructose-1,6-bisphosphatase (FBPase; EC 3.1.3.11) isozymes is influenced by AMP, Ca2+ and by reversible interactions with subcellular structures. In contrast to mammalian and avian isozymes, the kinetic properties of FBPases from ectothermal vertebrates are not fully described. To get some insight into mechanism of glycogen resynthesis in ectothermal vertebrates we examined the features of FBPases isolated from Cyprinus carpio skeletal muscle and liver. To investigate the evolutionary origin of the sensitivity of FBPase to effectors, we performed a phylogenetic analysis of known animal amino acids sequences of the enzyme. Based on our findings, we hypothesize that the high, mammalian-like, sensitivity of FBPase to Ca2+ is not essential for controlling the stability of glyconeogenic complex in striated muscles, instead it ensures the precise regulation of mitochondrial metabolism during prolonged Ca2+ elevation in contracting muscle fibers. Comparison of the kinetic properties of vertebrate and insect FBPases suggests that the high sensitivity of muscle isozyme to inhibitors has arisen as an adaptation enabling coordination of energy metabolism in warm-blooded animals.
authors.affiliation: Department of Animal Molecular Physiology, Wroclaw University, Cybulskiego 30, 50-205 Wroclaw, Poland.
authors.forename: Agnieszka
authors.initials: A
authors.lastname: Gizak
authors.forename: Agnieszka Joanna
authors.initials: AJ
authors.lastname: Sok
authors.forename: Anna
authors.initials: A
authors.lastname: Lipinska
authors.forename: Marek
authors.initials: M
authors.lastname: Zarzycki
authors.forename: Dariusz
authors.initials: D
authors.lastname: Rakus
authors.forename: Andrzej
authors.initials: A
authors.lastname: Dzugaj
mesh_terms: D000249:Adenosine Monophosphate / Q000494:pharmacology / Q000502:physiology*; D000818:Animals; D002118:Calcium / Q000494:pharmacology / Q000502:physiology*; D002347:Carps / Q000378:metabolism*; D019143:Evolution, Molecular; D006597:Fructose-Bisphosphatase / Q000378:metabolism*; D007700:Kinetics; D008099:Liver / Q000201:enzymology* / Q000378:metabolism; D009132:Muscles / Q000201:enzymology* / Q000378:metabolism; D010802:Phylogeny
chemical_list: D000249:Adenosine Monophosphate; D006597:Fructose-Bisphosphatase; D002118:Calcium