Folate-dependent enzymes in cultured Chinese hamster cells: folylpolyglutamate synthetase and its absence in mutants auxotrophic for clycine + adenosine + thymidine

Journal Article · Sat Jan 01 04:00:00 EST 1977 · Arch. Biochem. Biophys.; (United States)

DOI:https://doi.org/10.1016/0003-9861(77)90512-4· OSTI ID:6725715

Taylor, R T; Hanna, M L

Twelve out of 16 revertant clones that were isolated from CHO AUXB1 in media lacking glycine + adenosine + thymidine contained 44 to 66% of the wild-type level of H/sub 4/PteGluGlu synthetase activity. Both parent CHO and V-79 extracts catalyzed the conversion of H/sub 4/PteGluGlu and tetrahydropteroyltriglutamate to higher glutamyl conjugates. The AUXB1 and ght-1 mutant extracts again lacked these catalytic properties. In contrast, revertants of AUXB1 with about 50% of the wild-type H/sub 4/PteGluGlu synthetase activity displayed a proportionate ability to synthesize higher polyglutamyl conjugates. From our findings and published genetic data, we conclude that in cultured hamster cells a single synthetase can successively add at least three glutamates to H/sub 4/PteGlu. Loss of its function in certain mutants is responsible for their triple auxotrophy.

• Research Organization: Lawrence Livermore Lab., CA
• OSTI ID: 6725715
• Journal Information: Arch. Biochem. Biophys.; (United States), Journal Name: Arch. Biochem. Biophys.; (United States) Vol. 181; ISSN ABBIA
• Country of Publication: United States
• Language: English

Related Subjects

550200* -- Biochemistry
550400 -- Genetics
59 BASIC BIOLOGICAL SCIENCES
ADENOSINE
AMINO ACIDS
ANIMAL CELLS
ANIMALS
ATP
AZINES
BIOCHEMICAL REACTION KINETICS
CARBOXYLIC ACIDS
CELL CULTURES
ENZYMES
GLUTAMIC ACID
GLYCINE
HAMSTERS
HETEROCYCLIC COMPOUNDS
KINETICS
LIGASES
MAMMALS
MUTANTS
NUCLEOSIDES
NUCLEOTIDES
ORGANIC ACIDS
ORGANIC COMPOUNDS
ORGANIC NITROGEN COMPOUNDS
PYRIMIDINES
REACTION KINETICS
RIBOSIDES
RODENTS
THYMIDINE
VERTEBRATES