RESUMO
High telomerase activity is always associated with actively dividing cells, however the detection of this activity in dividing Leishmania and Trypanosoma cruzi cells has always been disappointingly low. Recently, we have found that Leishmania major telomerase activity can be activated by heat, which combined with dilutions of the nuclear extracts produced an increase in activity comparable to cancer cells. Here we examined whether T. cruzi telomerase shares the same physicochemical properties of primer specificity and overall features of the L. major. Our studies revealed that no telomerase inhibitory factors were present in the nuclear lysates of T. cruzi however the enzyme was activated by heat and was very resilient to heat denaturation. We also showed the extension primer specificity, susceptibility to RNase-A and RNase-H digestion, and the effect of telomerase inhibitors.
Assuntos
Telomerase/metabolismo , Trypanosoma cruzi/enzimologia , Inibidores Enzimáticos/metabolismo , Estabilidade Enzimática , Temperatura Alta , Desnaturação Proteica/efeitos da radiação , Estabilidade Proteica , Ribonuclease H/metabolismo , Ribonuclease Pancreático/metabolismo , Especificidade por Substrato , Telomerase/antagonistas & inibidores , Telomerase/químicaRESUMO
Here we studied the telomerase activity of the human parasite Leishmania major. In this organism we have detected a high activity of this enzyme once several parameters such as heat activation, sequence of extension primer, and protein concentration are adjusted. The activity was not only heat activated, but also very resistant to heat denaturation. We believe L. major telomerase is an important activity and it may provide an adequate drug therapy target.