title: Extracellular phosphorylation in Leishmania major and Leishmania mexicana during heat shock transformation.
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.
authors.affiliation: Instituto de Medicina Tropical, Universidad Central de Venezuela, Caracas.
authors.forename: T
authors.initials: T
authors.lastname: Hermoso
authors.forename: J L
authors.initials: JL
authors.lastname: Pérez
authors.forename: L
authors.initials: L
authors.lastname: Cornivelli
authors.forename: A G
authors.initials: AG
authors.lastname: Hernandez
mesh_terms: D000818:Animals; D003470:Culture Media / Q000737:chemistry; D006657:Histones / Q000378:metabolism; D006358:Hot Temperature; D018320:Leishmania major / Q000378:metabolism / Q000502:physiology*; D007894:Leishmania mexicana / Q000378:metabolism / Q000502:physiology*; D010766:Phosphorylation; D011479:Protamines / Q000378:metabolism; D013045:Species Specificity; D013997:Time Factors
chemical_list: D003470:Culture Media; D006657:Histones; D011479:Protamines