STAGE-SPECIFIC REGULATION OF PROTEIN-PHOSPHORYLATION IN LEISHMANIA-MAJOR
STAGE-SPECIFIC REGULATION OF PROTEIN-PHOSPHORYLATION IN LEISHMANIA-MAJOR
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DOI：
10.1016/0166-6851(94)00030-1
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发表时间：
1994-04-01
影响因子：
1.5
通讯作者：
ENGEL, JN
中科院分区：
文献类型：
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作者：
DELL, KR;ENGEL, JN
我们调查是否有蛋白磷酸化或蛋白激酶活性的变化，在生活周期的利什曼原虫。使用激酶复性试验，我们在生命周期的每个阶段检测到了几种利什曼原虫激酶。特别是，我们确定了一个50 kDa的激酶，是活跃的前循环和后循环的寄生虫，但无鞭毛体是无效的。体外磷酸化试验表明，丝氨酸和苏氨酸磷酸化蛋白质的模式在利什曼原虫的生命周期中进行调节，特别是在108-，62-，52-和49-kDa的蛋白质的磷酸化的变化被检测到。我们目前的证据表明，在108-，62-和52-kDa的蛋白质的磷酸化的变化是由于一个或多个无鞭毛体特异性磷酸酶的活性。在不同阶段的裂解物中，丝氨酸、苏氨酸和酪氨酸残基磷酸化的相对比率没有检测到差异。此外，对不同来源的L.主要发育阶段与用磷酸酪氨酸的商业抗体检测的相似。一个37 kDa的磷酸化蛋白与抗体反应强烈，并与37 kDa的蛋白在体外磷酸化试验中确定的comigrated。我们的研究结果支持这一假设，蛋白磷酸化起着重要作用的信号转导途径在利什曼原虫。
We investigated whether there are changes in protein phosphorylation or protein kinase activities during the life cycle of Leishmania major. Using a kinase renaturation assay, we detected several leishmanial kinases at each stage of the life cycle. In particular we identified a 50-kDa kinase that is active in procyclic and metacyclic parasites but is inactive in amastigotes. An in vitro phosphorylation assay demonstrated that the pattern of serine and threonine phosphorylated proteins was regulated during the leishmanial life cycle; specifically changes in the phosphorylation of a 108-, a 62-, a 52- and a 49-kDa protein were detected. We present evidence that suggests that changes in phosphorylation of the 108-, 62- and 52-kDa proteins are due to the activity of one or more amastigote specific phosphatases. No differences were detectable in the relative ratios of phosphorylation on serine, threonine, and tyrosine residues in lysates from the different stages. In addition, the pattern of tyrosine phosphorylated proteins in lysates from different L. major developmental stages was similar as detected with a commercial antibody to phosphotyrosine. A 37-kDa phosphorylated protein reacted strongly with the antibody and comigrated with a 37-kDa protein identified in the in vitro phosphorylation assay. Our results support the hypothesis that protein phosphorylation plays an important role in signal transduction pathways in Leishmania major.