Ogueta S B, Macintosh G C, Téllez-Iñon M T
Instituto de Investigaciones en Ingeniería Genética y Biología Molecular (INGEBI), Universidad de Buenos Aires, Argentina.
J Eukaryot Microbiol. 1998 Jul-Aug;45(4):392-6. doi: 10.1111/j.1550-7408.1998.tb05089.x.
The presence of Ca2+/calmodulin (Ca2+/CaM)-dependent protein kinase (TcCaM K) and some stage-specific substrates that appeared during morphogenesis of the parasite Trypanosoma cruzi were identified. Western blot analysis using a polyclonal antibody against rat brain CaM K type 11 recognized the same subunit composition (52, 59/62 kDa) observed for the mammalian enzyme, as well as the previously characterized TcCaM K found in epimastigote forms. Differential protein phosphorylation profiles were observed after enzyme activation in the stages of T. cruzi. Co-immunoprecipitation of stage-specific substrates with the TcCaM K suggested that the enzyme might be involved in the phosphorylation of a different set of proteins through the life cycle. Three phosphoproteins, pp105 and pp87 from epimastigotes and pp23 from trypomastigotes were identified as potential substrates for TcCaM K. The characterization of these endogenous stage markers might be a useful tool to understand the developmental cycles of these pathogenic protozoa.
已鉴定出在克氏锥虫寄生虫形态发生过程中存在的Ca2+/钙调蛋白（Ca2+/CaM）依赖性蛋白激酶（TcCaM K）以及一些阶段特异性底物。使用针对大鼠脑CaM K II型的多克隆抗体进行的蛋白质免疫印迹分析，识别出了与哺乳动物酶相同的亚基组成（52、59/62 kDa），以及之前在无鞭毛体形式中鉴定出的TcCaM K。在克氏锥虫的不同阶段，酶激活后观察到了不同的蛋白质磷酸化谱。阶段特异性底物与TcCaM K的共免疫沉淀表明，该酶可能在整个生命周期中参与了不同蛋白质组的磷酸化。三种磷蛋白，即无鞭毛体的pp105和pp87以及锥鞭毛体的pp23，被鉴定为TcCaM K的潜在底物。这些内源性阶段标志物的表征可能是理解这些致病原生动物发育周期的有用工具。
