title: Cell cycle regulation of the glyceraldehyde-3-phosphate dehydrogenase/uracil DNA glycosylase gene in normal human cells.
abstract: The cell cycle regulation of the glyceraldehyde-3-phosphate dehydrogenase (GAPDH)/uracil DNA glycosylase (UDG) gene was examined in normal human cells. Steady state RNA levels were monitored by Northern blot analysis using a plasmid (pChug 20.1) which contained the 1.3 kb GAPDH/UDG cDNA. The biosynthesis of the 37 kDa GAPDH/UDG protein was determined using an anti-human placental GAPDH/UDG monoclonal antibody to immunoprecipitate the radiolabeled protein. Increases in steady state GAPDH/UDG mRNA levels were cell cycle specific. A biphasic pattern was observed resulting in a 19-fold increase in the amount of GAPDH/UDG mRNA. The biosynthesis of the 37 kDa GAPDH/UDG protein displayed a similar biphasic regulation with a 7-fold increase. Pulse-chase experiments revealed a remarkably short half life of less than 1 hr. for the newly synthesized 37 kDa protein, comparable to that previously documented for a number of oncogenes. GAPDH/UDG mRNA levels were markedly reduced at 24 hr. when DNA synthesis was maximal. These results define the GAPDH/UDG gene as cell cycle regulated with a characteristic temporal sequence of expression in relation to DNA synthesis. The cell cycle synthesis of a labile 37 kDa monomer suggests a possible regulatory function for this multidimensional protein. Further, modulation of the GAPDH/UDG gene in the cell cycle may preclude its use as a reporter gene when the proliferative state of the cell is not kept constant.
authors.affiliation: Fels Institute for Cancer Research and Molecular Biology, Temple University School of Medicine, Philadelphia, PA 19140.
authors.forename: N R
authors.initials: NR
authors.lastname: Mansur
authors.forename: K
authors.initials: K
authors.lastname: Meyer-Siegler
authors.forename: J C
authors.initials: JC
authors.lastname: Wurzer
authors.forename: M A
authors.initials: MA
authors.lastname: Sirover
mesh_terms: D002453:Cell Cycle / Q000235:genetics*; D002478:Cells, Cultured; D045647:DNA Glycosylases; D015971:Gene Expression Regulation, Enzymologic; D005987:Glyceraldehyde-3-Phosphate Dehydrogenases / Q000096:biosynthesis / Q000235:genetics*; D006801:Humans; D008969:Molecular Sequence Data; D009097:Multienzyme Complexes / Q000096:biosynthesis / Q000235:genetics; D009699:N-Glycosyl Hydrolases / Q000096:biosynthesis / Q000235:genetics*; D012333:RNA, Messenger / Q000378:metabolism; D016196:S Phase; D051981:Uracil-DNA Glycosidase
chemical_list: D009097:Multienzyme Complexes; D012333:RNA, Messenger; D005987:Glyceraldehyde-3-Phosphate Dehydrogenases; D045647:DNA Glycosylases; D009699:N-Glycosyl Hydrolases; D051981:Uracil-DNA Glycosidase