Jillapalli Ravi, Narwal Sunil Kumar, Kolli Surendra Kumar, Mastan Babu S, Segireddy Rameswara Reddy, Dey Sandeep, Srivastava Pratik Narain, Mishra Satish, Kumar Kota Arun
Department of Animal Biology, School of Life Sciences, University of Hyderabad, Hyderabad 500046, India.
Division of Parasitology, CSIR-Central Drug Research Institute, Lucknow 226031, India.
Biol Open. 2019 Aug 23;8(8):bio042028. doi: 10.1242/bio.042028.
In , protein kinases govern key biological processes of the parasite life cycle involved in the establishment of infection, dissemination and sexual reproduction. The rodent malaria model encodes for 66 putative eukaryotic protein kinases (ePKs) as identified through modelling domain signatures and are highly conserved in We report here the functional characterisation of a putative serine-threonine kinase identified in this kinome analysis and designate it as To elucidate its role, we knocked out locus and performed a detailed phenotypic analysis at different life cycle stages. The knockout (KO) was not compromised in asexual blood stage propagation, transmission and development in the mosquito vector. The KO produced viable salivary gland sporozoites that successfully transformed into exo-erythrocytic forms (EEFs) and were morphologically indistinguishable from wild-type GFP (WT GFP) with regard to size and shape until 48 h. An intravenous dose of 1×10 KO sporozoites in C57BL/6 mice failed to establish blood stage infection and a higher dose of 5X10 showed a 2-3 day delay in prepatency as compared to WT GFP parasites. Consistent with such an observation, analysis of EEF development at 62 h revealed that the hepatic merozoite numbers were reduced to nearly 40% as compared to WT GFP and showed meagre expression of MSP1. Our studies provide evidence for the role of STK2 in late liver stage development and for the successful establishment of a timely blood stage infection.
在疟原虫中，蛋白激酶控制着寄生虫生命周期中涉及感染建立、传播和有性繁殖的关键生物学过程。通过建模结构域特征鉴定，啮齿动物疟疾模型编码66种假定的真核蛋白激酶（ePKs），并且在[具体物种]中高度保守。我们在此报告在该激酶组分析中鉴定出的一种假定的丝氨酸 - 苏氨酸激酶的功能特征，并将其命名为[具体名称]。为了阐明其作用，我们敲除了[具体基因座]，并在不同生命周期阶段进行了详细的表型分析。[具体基因]敲除（KO）在无性血液阶段的繁殖、在蚊媒中的传播和发育方面未受影响。[具体基因]敲除产生了有活力的唾液腺子孢子，这些子孢子成功转化为红细胞外期形式（EEFs），并且在48小时之前，在大小和形状方面与野生型绿色荧光蛋白（WT GFP）在形态上无法区分。在C57BL / 6小鼠中静脉注射1×10[具体数量]的[具体基因]敲除子孢子未能建立血液阶段感染，与WT GFP寄生虫相比，更高剂量的5×10[具体数量]显示出潜伏期延迟2 - 3天。与这种观察结果一致，在62小时对[具体基因]敲除的红细胞外期发育分析表明，与WT GFP相比，肝内裂殖子数量减少到近40％，并且MSP1表达微弱。我们的研究为STK2在肝脏晚期发育中的作用以及及时建立血液阶段感染提供了证据。
