Critical importance of the de novo pyrimidine biosynthesis pathway for Trypanosoma cruzi growth in the mammalian host cell cytoplasm.
The intracellular parasitic protist Trypanosoma cruzi is the causative agent of Chagas disease in Latin America. In general, pyrimidine nucleotides are supplied by both de novo biosynthesis and salvage pathways. While epimastigotes-an insect form-possess both activities, amastigotes-an intracellular replicating form of T. cruzi-are unable to mediate the uptake of pyrimidine. However, the requirement of de novo pyrimidine biosynthesis for parasite growth and survival has not yet been elucidated. Carbamoyl-phosphate synthetase II (CPSII) is the first and rate-limiting enzyme of the de novo biosynthetic pathway, and increased CPSII activity is associated with the rapid proliferation of tumor cells. In the present study, we showed that disruption of the T. cruzi cpsII gene significantly reduced parasite growth. In particular, the growth of amastigotes lacking the cpsII gene was severely suppressed. Thus, the de novo pyrimidine pathway is important for proliferation of T. cruzi in the host cell cytoplasm and represents a promising target for chemotherapy against Chagas disease.
Department of Molecular and Cellular Parasitology, Juntendo University School of Medicine, Bunkyo-ku, Tokyo, Japan. muneaki@juntendo.ac.jp
Muneaki
M
Hashimoto
Jorge
J
Morales
Yoshihisa
Y
Fukai
Shigeo
S
Suzuki
Shinzaburo
S
Takamiya
Akiko
A
Tsubouchi
Syou
S
Inoue
Masayuki
M
Inoue
Kiyoshi
K
Kita
Shigeharu
S
Harada
Akiko
A
Tanaka
Takashi
T
Aoki
Takeshi
T
Nara
D002223:Carbamoyl-Phosphate Synthase (Glutamine-Hydrolyzing) / Q000235:genetics; D014355:Chagas Disease / Q000378:metabolism* / Q000469:parasitology*; D003593:Cytoplasm / Q000378:metabolism / Q000469:parasitology*; D055786:Gene Knockout Techniques; D006367:HeLa Cells; D006801:Humans; D011743:Pyrimidines / Q000096:biosynthesis*; D014349:Trypanosoma cruzi / Q000235:genetics / Q000254:growth & development*
D011743:Pyrimidines; D002223:Carbamoyl-Phosphate Synthase (Glutamine-Hydrolyzing); C030986:pyrimidine