RNA interference of a trypanosome topoisomerase II causes progressive lossof mitochondrial DNA

Citation
Zf. Wang et Pt. Englund, RNA interference of a trypanosome topoisomerase II causes progressive lossof mitochondrial DNA, EMBO J, 20(17), 2001, pp. 4674-4683
Citations number
57
Categorie Soggetti
Molecular Biology & Genetics
Journal title
EMBO JOURNAL
ISSN journal
02614189 → ACNP
Volume
20
Issue
17
Year of publication
2001
Pages
4674 - 4683
Database
ISI
SICI code
0261-4189(20010903)20:17<4674:RIOATT>2.0.ZU;2-9
Abstract
We studied the function of a Trypanosoma brucei topoisomerase II using RNA interference (RNAi). Expression of a topoisomerase II double-stranded RNA a s a stem-loop caused specific degradation of mRNA followed by loss of prote in. After 6 days of RNAi, the parasites' growth rate declined and the cells subsequently died. The most striking phenotype upon induction of RNAi was the loss of kinetoplast DNA (kDNA), the cell's catenated mitochondrial DNA network. The loss of kDNA was preceded by gradual shrinkage of the network and accumulation of gapped free minicircle replication intermediates. These facts, together with the localization of the enzyme in two antipodal sites flanking the kDNA, show that a function of this topoisomerase II is to att ach free minicircles to the network periphery following their replication.