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Extracellular phosphorylation in Leishmania major and Leishmania mexicana during heat shock transformation
T Hermoso1, J L Pérez, L Cornivelli
1Instituto de Medicina Tropical, Universidad Central de Venezuela, Caracas.
Abstract:
The extracellular phosphorylation of exogenous substrates have been studied in two Leishmania isolates, L. mexicana and L. major, that differ in their capacity to transform from promastigotes to amastigote-like cells when submitted to heat shock condition. When submitted to heat shock both parasites showed an increase in their extracellular phosphorylation activity. L. major promastigotes that do not transform to amastigote-like cells at 37 degrees C, do not phosphorylate exogenous substrate when the culture is grown at 25 degrees C. In contrast, L. mexicana promastigotes, that transform to amastigote-like cells at 37 degrees C, showed a strong phosphorylation at this temperature. As response to heat shock exposure, the extracellular phosphorylation for L. major increases steadily reaching a maximum at 360 min. On the other hand, L. mexicana also show an increase in phosphorylation during transformation, but in this case the maximum was detected after 10 min. The results are discussed in relationship to the capacity of the parasite to survive once inside the vertebrate host.
Insights
Leishmania parasites exhibit increased extracellular phosphorylation upon heat shock. Leishmania mexicana, which transforms to amastigote-like cells, shows stronger phosphorylation than Leishmania major.
Area of Science:
- Parasitology
- Molecular Biology
- Biochemistry
Background:
- Leishmania parasites are protozoan pathogens responsible for leishmaniasis.
- Parasite transformation between life stages is crucial for disease transmission and survival.
- Extracellular enzymatic activity may play a role in parasite-host interactions.
Purpose of the Study:
- To investigate extracellular phosphorylation differences between Leishmania mexicana and Leishmania major.
- To correlate phosphorylation activity with the parasites' capacity for heat-shock-induced transformation.
- To understand the implications for parasite survival within the vertebrate host.
Main Methods:
- Culturing Leishmania mexicana and Leishmania major promastigotes under varying temperature conditions (25°C and 37°C).
- Assessing extracellular phosphorylation of exogenous substrates in response to heat shock.
- Measuring phosphorylation activity over time following heat shock exposure.
Main Results:
- Both Leishmania species showed increased extracellular phosphorylation after heat shock.
- Leishmania mexicana, which transforms to amastigote-like cells at 37°C, exhibited strong phosphorylation at this temperature.
- Leishmania major, which does not transform at 37°C, showed minimal phosphorylation when grown at 25°C, with activity increasing over 360 minutes post-heat shock.
- Leishmania mexicana displayed a rapid increase in phosphorylation, peaking at 10 minutes post-heat shock.
Conclusions:
- Extracellular phosphorylation is modulated by heat shock in Leishmania.
- The capacity for transformation correlates with enhanced extracellular phosphorylation, particularly in Leishmania mexicana.
- These findings suggest a potential role for extracellular phosphorylation in Leishmania's adaptation and survival within the mammalian host.