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Long‐Term Alcohol Effects on Hepatic Phosphoglucomutase Activities in Relation to Posttranslational Modification of the Protein
Author(s) -
Nomura Fumio,
Miyake Masami,
Noda Masatoshi,
Itoga Sakae,
Nakai Toshiaki
Publication year - 1998
Publication title -
alcoholism: clinical and experimental research
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.267
H-Index - 153
eISSN - 1530-0277
pISSN - 0145-6008
DOI - 10.1111/acer.1998.22.s3_part1.121s
Subject(s) - phosphoglucomutase , alcohol , biochemistry , adp ribosylation , enzyme , chemistry , metabolism , biology , nad+ kinase
ADP‐ribosylation is a posttranslational protein modification catalyzed by two classes of enzymes: mono‐ADP‐ribosyttransferase and poly‐ADP‐ribose polymerases. We previously demonstrated that long‐term alcohol intake remarkably enhanced an endogenous ADP‐ribosylation of a 58 kDa protein in rat liver and also identified the 58 kDa protein as phosphoglucomutase (PGM). To assess biological significance of this phenomenon, we tested the effects of long‐term alcohol intake on PGM activities in connection with posttranslational modification of the protein. ADP‐ribosylation of PGM was mono‐ rather than poly‐ADP‐ribosylation. Also, nonenzymatic binding of ADP‐ribose was excluded. It was of note that ADP‐ribosylation of exogenous PGM was remarkably increased by adding rat liver plasma membranes, and that the extent of the increase was greater in alcohol‐fed rats than in pair‐fed controls. Furthermore, PGM activities were significantly increased after long‐term alcohol intake concomitant with increased ADP‐ribosyltransferase activities toward PGM. In view of the variety of roles of PGM in the liver, such as carbohydrate metabolism and Ca 2+ homeostasis, it is tempting to speculate that increased ADP‐ribosylation of PGM may play a role in long‐term alcohol effects on hepatocytes.