title: Protein kinase activities in Leishmania aethiopica: control by growth, transformation and inhibitors.
abstract: Promastigotes of L. aethiopica express an ectokinase activity preferring histone V-S as substrate. A soluble kinase activity utilizing protamine and histone V-S, as well as a particulate fraction associated kinase activity preferring protamine are also expressed. The soluble histone kinase activity, but not the ectokinase, was expressed at a higher level in cells from late phases of growth, as compared to early log phase cultures. Transformation of L. aethiopica to an amastigote-like stage, resulted in almost complete loss of the kinase activities, with retained viability of the cells. Formycin-ATP only weakly inhibited the kinases while effectively inhibiting cell growth and thymidine incorporation. Staurosporin efficiently blocked the kinase activities and cell growth without affecting thymidine incorporation.
authors.affiliation: Department of Biochemistry, Addis Ababa University, Faculty of Medicine, Ethiopia.
authors.forename: D
authors.initials: D
authors.lastname: Assefa
authors.forename: Y
authors.initials: Y
authors.lastname: Worku
authors.forename: G
authors.initials: G
authors.lastname: Skoglund
mesh_terms: D000470:Alkaloids / Q000494:pharmacology; D000818:Animals; D005573:Formycins / Q000494:pharmacology; D006657:Histones; D006801:Humans; D007891:Leishmania / Q000187:drug effects / Q000201:enzymology* / Q000254:growth & development; D016773:Leishmaniasis, Cutaneous / Q000469:parasitology; D011479:Protamines; D047428:Protein Kinase Inhibitors; D011494:Protein Kinases / Q000378:metabolism*; D012265:Ribonucleotides / Q000494:pharmacology; D012995:Solubility; D019311:Staurosporine; D013347:Subcellular Fractions / Q000201:enzymology; D013379:Substrate Specificity
chemical_list: D000470:Alkaloids; D005573:Formycins; D006657:Histones; D011479:Protamines; D047428:Protein Kinase Inhibitors; D012265:Ribonucleotides; C032552:formycin triphosphate; D011494:Protein Kinases; D019311:Staurosporine