Molecular Characterization of a Carbamoyl-Phosphate Synthetase II (CPS II) Gene from Trypanosoma cruzi

Aoki, Takashi; Shimogawara, Rieko; Ochiai, Kaoru; Yamasaki, Hiroshi; Shimada, Junko

doi:10.1007/978-1-4615-2584-4_108

Cited by 12 publications

(2 citation statements)

References 5 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…In contrast, the eukaryotic CPSII has an N-terminal GATase that is fused to the CPS polypeptide, as well as possessing fused C-terminal domains that catalyze subsequent steps in pyrimidine biosynthesis (Jones, 1980; Davis, 1986; Davidson et al, 1993). Protozoa that include medically important parasites ( Plasmodium , Toxoplasma , Babesia , Trypanosoma , Leishmaina ) possess a single atypical and simplified eukaryotic CPSII comprising an N-terminal GATase fused to CPS via an atypically short linker but do not possess fused C-terminal domains that catalyze subsequent steps in pyrimidine biosynthesis (Aoki et al, 1994; Flores et al, 1994; Chansiri and Bagnara, 1995; Gao et al, 1998; Nara et al, 1998; Gao et al, 1999; Fox and Bzik, 2003). Because these subsequent enzyme activities of the de novo pyrimidine pathway are not directly fused to the C-terminus of protozoan forms of CPSII, we could easily engineer a functional CPSII minigene to evaluate genetic complementation of T. gondii CPSII function in vivo .…”

Section: Introductionmentioning

confidence: 99%

Genetic identification of essential indels and domains in carbamoyl phosphate synthetase II of Toxoplasma gondii

Fox

Ristuccia

Bzik

2009

International Journal for Parasitology

View full text Add to dashboard Cite

New treatments need to be developed for the significant human diseases of toxoplasmosis and malaria to circumvent problems with current treatments and drug resistance. Apicomplexan parasites causing these lethal diseases are deficient in pyrimidine salvage suggesting that selective inhibition of de novo pyrimidine biosynthesis can lead to a severe loss of UMP and dTMP pools thereby inhibiting parasite RNA and DNA synthesis. Disruption of Toxoplasma gondii carbamoyl phosphate synthetase II (CPSII) induces a severe uracil auxotrophy with no detectable parasite replication in vitro and complete attenuation of virulence in mice. Here we show that a CPSII cDNA minigene efficiently complements the uracil auxotrophy of CPSII deficient mutants restoring parasite growth and virulence. Our complementation assays reveal that engineered mutations within or proximal to the catalytic triad of the N-terminal glutamine amidotransferase (GATase) domain inactivate the complementation activity of T. gondii CPSII and demonstrate a critical dependence on the apicomplexan CPSII GATase domain in vivo. Surprisingly, indels present within the T. gondii CPSII GATase domain as well as the C-terminal allosteric regulatory domain are found to be essential. In addition several mutations directed at residues implicated in allosteric regulation in Escherichia coli CPS either abolish or markedly suppress complementation and further define the functional importance of the allosteric regulatory region. Collectively, these findings identify novel features of T. gondii CPSII as potential parasite-selective targets for drug development.

show abstract

Section: Introductionmentioning

confidence: 99%

Genetic identification of essential indels and domains in carbamoyl phosphate synthetase II of Toxoplasma gondii

Fox

Ristuccia

Bzik

2009

International Journal for Parasitology

View full text Add to dashboard Cite

show abstract

“…Kinetoplastids such as Trypanosoma and Leishmania have well-developed and functional de novo and salvage pathway for the biosynthesis of pyrimidines [ 11 – 13 ]. The first three steps in the de novo pyrimidine pathway of T. cruzi should be catalyzed by independent single enzymes, a notion which has been stemmed from the finding that the open reading frames (ORFs) coding for these enzymes have leader sequences and mRNA splice sites [ 14 , 15 ]. Also, it was hinted that the enzymes may not interact covalently but may exhibit weak interactions.…”

Section: Enzymes Of the Pyrimidine Pathway Of Trypanosomatidsmentioning

confidence: 99%

Fresh insights into the pyrimidine metabolism in the trypanosomatids

Tiwari

Dubey

2018

Parasites Vectors

View full text Add to dashboard Cite

The trypanosomatid parasites continue their killing spree resulting in significant annual mortality due to the lack of effective treatments and the prominence of these diseases in poorer countries. These dimorphic parasites thrive unchecked in the host system, outsmarting the immune mechanisms. An understanding of biology of these parasitic forms will help in the management and elimination of these fatal diseases. Investigation of various metabolic pathways in these parasites has shed light in the understanding of the unique biology of the trypansomatids. An understanding of these pathways have helped in tracing the soft targets in the metabolic pathways, which could be used as effective drug targets which would further impact the therupeutic implications. Pyrimidine pathway is a vital metabolic pathway which yields in the formation of pyrimidines, which are then integrated in nucleic acids (DNA and RNA) in sugars (UDP sugars) and lipids (CDP lipids). A wealth of data and information has been generated in the past decades by in-depth analyses of pyrimidine pathway in the trypanosomatid parasites, which can aid in the identification of anomalies between the parasitic and host counterpart which could be further harnessed to develop therapeutic interventions for the treatment of parasitic diseases. This review presents an updated and comprehensive detailing of the pyrimidine metabolism in the trypansomatids, their uniqueness and their distinctions, and its possible outcomes that would aid in the eradication of these parasitic diseases.

show abstract

Novel organization and sequences of five genes encoding all six enzymes for de novo pyrimidine biosynthesis in Trypanosoma cruzi

Gao

Nara

Nakajima‐Shimada

et al. 1999

Journal of Molecular Biology

View full text Add to dashboard Cite

Molecular Characterization of a Carbamoyl-Phosphate Synthetase II (CPS II) Gene from Trypanosoma cruzi

Cited by 12 publications

References 5 publications

Genetic identification of essential indels and domains in carbamoyl phosphate synthetase II of Toxoplasma gondii

Genetic identification of essential indels and domains in carbamoyl phosphate synthetase II of Toxoplasma gondii

Fresh insights into the pyrimidine metabolism in the trypanosomatids

Novel organization and sequences of five genes encoding all six enzymes for de novo pyrimidine biosynthesis in Trypanosoma cruzi

Contact Info

Product

Resources

About