title: Age-related changes in protein phosphorylation by rat hepatocytes.
abstract: The qualitative and quantitative changes in the phosphorylation of specific proteins in hepatocyte suspension from 5-, 12- and 22-month-old male Fischer F344 rats were analyzed by two-dimensional polyacrylamide gel electrophoresis. No qualitative changes in phosphorylation of individual proteins were observed with age. In addition, very few quantitative changes (less than 2% of proteins studied) in protein phosphorylation were detected. The phosphorylation of two acidic proteins decreased (50%) with age while the phosphorylation of one basic protein increased (300%) with age. The two acidic proteins and one basic protein that showed quantitative changes with age were found predominately in the microsome and nuclear fractions of hepatocytes, respectively. The effect of dietary restriction on the phosphorylation of proteins in male Fischer F344 rats was also studied. Although, dietary restriction alters the age-related incident of disease and prolongs longevity, it did not have any significant effect on phosphorylation of individual proteins in the liver.
authors.affiliation: Department of Biology, Illinois State University, Normal 61761.
authors.forename: A R
authors.initials: AR
authors.lastname: Heydari
authors.forename: J A
authors.initials: JA
authors.lastname: Butler
authors.forename: S M
authors.initials: SM
authors.lastname: Waggoner
authors.forename: A
authors.initials: A
authors.lastname: Richardson
mesh_terms: D000375:Aging / Q000378:metabolism*; D000818:Animals; D004032:Diet; D004591:Electrophoresis, Polyacrylamide Gel; D008099:Liver / Q000378:metabolism*; D008297:Male; D010749:Phosphoprotein Phosphatases / Q000378:metabolism; D010750:Phosphoproteins / Q000378:metabolism; D010766:Phosphorylation; D011494:Protein Kinases / Q000378:metabolism; D011506:Proteins / Q000378:metabolism*; D051381:Rats; D011916:Rats, Inbred F344
chemical_list: D010750:Phosphoproteins; D011506:Proteins; D011494:Protein Kinases; D010749:Phosphoprotein Phosphatases