GONUTS has been updated to MW1.31 Most things seem to be working but be sure to report problems.
PMID:8068008
| Citation |
Gütlich, M, Jaeger, E, Rücknagel, KP, Werner, T, Rödl, W, Ziegler, I and Bacher, A (1994) Human GTP cyclohydrolase I: only one out of three cDNA isoforms gives rise to the active enzyme. Biochem. J. 302 ( Pt 1):215-21 |
|---|---|
| Abstract |
GTP cyclohydrolase I catalyses the first and rate-limiting step of tetrahydrobiopterin biosynthesis. Its expression is regulated by interferon-gamma or kit ligand in a tissue-specific manner. Three different cDNA forms have been reported for human GTP cyclohydrolase I [Togari, Ichinose, Matsumoto, Fujita and Nagatsu (1992) Biochem. Biophys. Res. Commun. 187, 359-365]. We have isolated, from a human liver cDNA library, two clones which contained inserts identical with two of the cDNAs reported by Togari et al. (1992). The three open reading frames corresponding to all reported cDNA sequences were expressed in Escherichia coli. Only the recombinant protein corresponding to the longest reading frame catalysed the conversion of GTP into dihydroneopterin triphosphate. The proteins corresponding to the shorter reading frames failed to catalyse not only the generation of dihydroneopterin triphosphate but also the release of formate from GTP, an intermediate step of the reaction. Recombinant human GTP cyclohydrolase I showed sigmoidal substrate kinetics and maximum activity at 60 degrees C. These findings are well in line with the published properties of the enzyme isolated from rat liver. The data indicate that cytokine-mediated induction of GTP cyclohydrolase I is not due to the expression of enzyme isoforms. |
| Links | |
| Keywords |
Amino Acid Sequence; Animals; DNA, Complementary; Enzyme Activation; Escherichia coli/genetics; Female; GTP Cyclohydrolase/genetics; GTP Cyclohydrolase/metabolism; Humans; Immune Sera; Isoenzymes/genetics; Isoenzymes/metabolism; Molecular Sequence Data; Open Reading Frames; Rabbits; Recombinant Proteins/metabolism |
| edit table |
Significance
Annotations
| Gene product | Qualifier | GO ID | GO term name | Evidence Code | with/from | Aspect | Notes | Status |
|---|---|---|---|---|---|---|---|---|
| edit table |
See also
References
See Help:References for how to manage references in GONUTS.
