title: S-Adenosylhomocysteine hydrolase as a target for intracellular adenosine action.
abstract: S-Adenosylhomocysteine hydrolase (AdoHcyase) controls intracellular levels of S-adenosylhomocysteine (AdoHcy). AdoHcy is a potent product inhibitor of some S-adenosylmethionine-dependent methyltransferases. Pharmacological modulation of AdoHcyase to indirectly inhibit methyltransferases can be guided by the fact that adenosine binds with high affinity to AdoHcyase and inhibits enzyme activity. cAMP can compete with adenosine and can counteract the adenosine-induced inhibition of AdoHcyase. Thus, the ratio between adenosine and cAMP, which can vary under different physiological conditions, might result in changes in, for example, DNA promoter methylation and therefore transcription.
authors.affiliation: Department of Pharmacology and Toxicology, Faculty of Medicine, University of Tübingen, Wilhelmstrasse 56, D-72074 Tübingen, Germany. doris.kloor@uni-tuebingen.de
authors.forename: Doris
authors.initials: D
authors.lastname: Kloor
authors.forename: Hartmut
authors.initials: H
authors.lastname: Osswald
mesh_terms: D000241:Adenosine / Q000494:pharmacology*; D043383:Adenosylhomocysteinase / Q000187:drug effects*; D000818:Animals; D000242:Cyclic AMP / Q000502:physiology; D006801:Humans; D008958:Models, Molecular; D012435:S-Adenosylhomocysteine / Q000378:metabolism
chemical_list: D012435:S-Adenosylhomocysteine; D000242:Cyclic AMP; D043383:Adenosylhomocysteinase; D000241:Adenosine