The rate-limiting step of uracil degradation in tomato cell suspension cultures and Euglena gracilis in vivo studies

Tintemann, H.; Wasternack, Claus; Benndorf, Rainer; Reinbothe, H.

doi:10.1016/0305-0491(85)90526-7

Cited by 3 publications

(6 citation statements)

References 24 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…(2004 ) have demonstrated that the main Ura transporters in Arabidopsis, AtUPS1 and AtUPS2, do not transport DHU and Ura differently. Tintemann et al . (1985 ) reported that unlabelled DHU did not affect the uptake of 14 C-Ura, but markedly reduced the catabolism of labelled Ura in tomato cells, consistent with DHU being an intermediate in the pathway for pyrimidine catabolism in plants.…”

Section: Resultsmentioning

confidence: 99%

“…(1985 ) reported that unlabelled DHU did not affect the uptake of 14 C-Ura, but markedly reduced the catabolism of labelled Ura in tomato cells, consistent with DHU being an intermediate in the pathway for pyrimidine catabolism in plants. Tintemann et al . (1985 ) also demonstrated that no labelling of Ura via the potentially reversible DHPDH step was observed with labelled DHU.…”

Section: Resultsmentioning

confidence: 99%

“…As PYD1 antibodies are presently unavailable, it was not possible to determine whether truncated PYD1 proteins were even made in the pyd1 mutants. Previous investigators have been unable to measure DHPDH in plant extracts (for example, Tintemann et al ., 1985 ), or for heterologously expressed Arabidopsis PYD1 protein (Z. Gojkovic, ZGene, Horsholm, Denmark, pers. comm.)…”

Section: Resultsmentioning

confidence: 99%

“…1 ). Labelling kinetic studies have shown that the Ura → DHU (PYD1) step of the pathway is rate limiting for [2- 14 C]-Ura degradation in tomato ( Tintemann et al ., 1985 ), and thus may represent an important site of regulation. Although DHPDH activities have been inferred from the above studies, they have not been detected in any plant, and the possible role of this enzyme in pyrimidine catabolism has not been elucidated.…”

Section: Introductionmentioning

confidence: 99%

See 3 more Smart Citations

A functional analysis of the pyrimidine catabolic pathway in Arabidopsis

et al. 2009

View full text Add to dashboard Cite

Reductive catabolism of pyrimidine nucleotides occurs via a three-step pathway in which uracil is degraded to β-alanine, CO2 and NH3 through sequential activities of dihydropyrimidine dehydrogenase (EC 1.3.1.2, PYD1), dihydropyrimidinase (EC 3.5.2.2, PYD2) and β-ureidopropionase (EC 3.5.1.6, PYD3).A proposed function of this pathway, in addition to the maintenance of pyrimidine homeostasis, is the recycling of pyrimidine nitrogen to general nitrogen metabolism. PYD expression and catabolism of [2-14C]-uracil are markedly elevated in response to nitrogen limitation in plants, which can utilize uracil as a nitrogen source.PYD1, PYD2 and PYD3 knockout mutants were used for functional analysis of this pathway in Arabidopsis. pyd mutants exhibited no obvious phenotype under optimal growing conditions. pyd2 and pyd3 mutants were unable to catabolize [2-14C]-uracil or to grow on uracil as the sole nitrogen source. By contrast, catabolism of uracil was reduced by only 40% in pyd1 mutants, and pyd1 seedlings grew nearly as well as wild-type seedlings with a uracil nitrogen source. These results confirm PYD1 function and suggest the possible existence of another, as yet unknown, activity for uracil degradation to dihydrouracil in this plant.The localization of PYD-green fluorescent protein fusions in the plastid (PYD1), secretory system (PYD2) and cytosol (PYD3) suggests potentially complex metabolic regulation.

show abstract

Section: Resultsmentioning

confidence: 99%

Section: Resultsmentioning

confidence: 99%

Section: Resultsmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

See 2 more Smart Citations

A functional analysis of the pyrimidine catabolic pathway in Arabidopsis

et al. 2009

View full text Add to dashboard Cite

show abstract

“…5, no. 40) residing in plastids, was shown to be rate limiting (Tintemann et al, 1985). Compared to mammalian DPYD, the plant enzyme lacks C-terminal domains for cofactor binding, which are involved in electron delivery to the active site.…”

Section: Pyrimidine Nucleotide Degradationmentioning

confidence: 99%