Telomerase in kinetoplastid parasitic protozoa

摘要

We have identified telomerase activity in extracts of threce evolutionarily diverse kinetoplastid species: Trypanosoma brucei, Leishmania major, and Leishmania tarentotae. Telomerase activity was initially detected in extracts from insect form cells of all three kinetoplastid species by using a modification of the one-tube telomere repeat amplification protocol [Kim, N., et al. (1994) Science 266, 2011- 2015], although better results were subsequently achieved with the two- tube telomere repeat amplification protocol [Autexier, C., Pruzan, R., Funk, W. k Greider, C. (1996) EMBO J 15, 5928-5935] . The activity in T brucei extracts was sufficiently robust to enable its detection in a direct assay of telomerase; enzyme Processivity was found to be relatively low. The in viyro properties of telomerase suggest a possible templating domain sequence for the telomerase RNA of T brucei. Telomerase activity is likely to contribute to telomere maintenance in these parasitic organisms and provides a new target for chemotherapeutic intervention.