Authors: Chaudhuri, Gautam
Farrow, Anitra L.
Misra, Smita
Title: Stage-specific expressions of four different ribonuclease H genes in Leishmania
Language (ISO): en
Abstract: The human pathogen of the genus Leishmania cause worldwide morbidity and infection of visceral organs by some species may be lethal. Lack of rational chemotherapy against these pathogens dictates the study of differential biochemistry and molecular biology of the parasite as compared to its human host. The ubiquitous enzyme ribonuclease H (RNase H, EC 3.1.26.4) cleaves the RNA from a RNA:DNA duplex and is critical for the replication of DNA in the nucleus and the mitochondria. We have characterized four RNase H genes from Leishmania: one is of type I (LRNase HI) and three others are of type II (LRNase HIIA, -HIIB and -HIIC). In contrast human cells have only one type I and one type II RNase H. All the four RNase H genes in Leishmania are single copy and located in discrete chromosomes. When expressed inside RNase H-deficient E. coli, all of the four Leishmania RNase H were capable to complement the genetic defect of the E. coli, indicating their identity as RNase H. The enzymes are differentially expressed in the promastigotes and the amastigotes, the forms that thrives in entirely different physico-chemical conditions in nature. Nucleotide sequences of the 5'-UTRs of three of these mRNAs have upstream open reading frames. Understanding the regulation of these four distinct ribonuclease H genes in Leishmania will help us better understand leishmanial parasitism and may help us to design rational chemotherapy against the pathogen.
Subject Headings: Amastigote
Leishmania major
Promastigotes
Ribonuclease H
Trypanosoma brucei
Trypanosoma cruzi
Upstream open reading frame
URI: http://hdl.handle.net/2003/25649
http://dx.doi.org/10.17877/DE290R-341
Issue Date: 2005-07-13
Appears in Collections:Original Articles

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