title: Methylenetetrahydrofolate dehydrogenases in normal and transformed mammalian cells.
abstract: Transformed mammalian cells express both the usual NADP-dependent trifunctional methylenetetrahydrofolate dehydrogenase-cyclohydrolase-synthetase as well as the bifunctional NAD-dependent methylenetetrahydrofolate dehydrogenase-cyclohydrolase. Antisera to these proteins do not crossreact, and Western blots of cell extracts indicate that there is no inactive form of the NAD-dependent enzyme in normal tissues. Immunofluorescence studies suggest a cytosolic location for the NAD-dependent enzyme, although sequence homology seen in the N-terminal 10 residues indicates a closer relationship with the mitochondrial form of the yeast NADP dependent trifunctional enzyme.
authors.affiliation: Department of Biochemistry, McGill University, Montreal, P.Q., Canada.
authors.forename: R E
authors.initials: RE
authors.lastname: MacKenzie
authors.forename: N
authors.initials: N
authors.lastname: Mejia
authors.forename: X M
authors.initials: XM
authors.lastname: Yang
mesh_terms: D000619:Aminohydrolases / Q000032:analysis* / Q000276:immunology / Q000302:isolation & purification; D000818:Animals; D000906:Antibodies / Q000276:immunology; D002460:Cell Line; D004591:Electrophoresis, Polyacrylamide Gel; D005260:Female; D005455:Fluorescent Antibody Technique; D005574:Formate-Tetrahydrofolate Ligase / Q000032:analysis* / Q000276:immunology / Q000302:isolation & purification; D006801:Humans; D008754:Methylenetetrahydrofolate Dehydrogenase (NADP) / Q000032:analysis* / Q000276:immunology / Q000302:isolation & purification; D051379:Mice; D009097:Multienzyme Complexes / Q000032:analysis* / Q000276:immunology / Q000302:isolation & purification; D009243:NAD / Q000502:physiology; D009249:NADP / Q000502:physiology; D009369:Neoplasms / Q000201:enzymology*; D010088:Oxidoreductases / Q000032:analysis*
chemical_list: D000906:Antibodies; D009097:Multienzyme Complexes; C055342:methylene tetrahydrofolate dehydrogenase-methenyltetrahydrofolate cyclohydrolase; D009243:NAD; D009249:NADP; C021836:formyl-methenyl-methylenetetrahydrofolate synthetase; D010088:Oxidoreductases; D008754:Methylenetetrahydrofolate Dehydrogenase (NADP); D000619:Aminohydrolases; D005574:Formate-Tetrahydrofolate Ligase