Characterization of Calcium-Dependent Protein Kinases 3, a Protein Involved in Growth of Cryptosporidium parvum

Qiang Zhang; Yaqiong Guo; Na Li; Yu Li; Jiayuan Su; Rui Xu; Ziding Zhang; Yaoyu Feng; Lihua Xiao

doi:10.3389/fmicb.2020.00907

Characterization of Calcium-Dependent Protein Kinases 3, a Protein Involved in Growth of Cryptosporidium parvum

Front Microbiol. 2020 May 8:11:907. doi: 10.3389/fmicb.2020.00907. eCollection 2020.

Authors

Qiang Zhang¹, Yaqiong Guo², Na Li², Yu Li³, Jiayuan Su¹, Rui Xu¹, Ziding Zhang³, Yaoyu Feng^{1

2}, Lihua Xiao²

Affiliations

¹ State Key Laboratory of Bioreactor Engineering, School of Resource and Environmental, East China University of Science and Technology, Shanghai, China.
² Key Laboratory of Zoonosis of Ministry of Agriculture, College of Veterinary Medicine, South China Agricultural University, Guangzhou, China.
³ State Key Laboratory of Agrobiotechnology, College of Biological Sciences, China Agricultural University, Beijing, China.

Abstract

Calcium-dependent protein kinases (CDPKs) are considered promising targets for pharmaceutical intervention of cryptosporidiosis. Whole-genome sequencing has revealed the presence of several CDPKs (CpCDPKs) in Cryptosporidium parvum. In this study, we expressed recombinant CpCDPK3 encoded by the cgd5_820 gene in Escherichia coli. The biologic characteristics and functions of CpCDPK3 were examined using qRT-PCR, immunofluorescence microscopy, and in vitro neutralization assay. The expression of the cgd5_820 gene peaked in merozoites during in vitro culture while the CpCDPK3 protein was expressed in both sporozoites and merozoites. Polyclonal antibodies against CpCDPK3 showed no significant inhibitory effects on host invasion by the parasites. We assessed the inhibitory effects of 46 candidate compounds from molecular docking of CpCDPK3 on both C. parvum development and CpCDPK3 enzyme activities. One compound was identified to be effective. Results of these analyses suggest that CpCDPK3 might play an important role in the growth of C. parvum.

Keywords: Cryptosporidium parvum; calcium-dependent protein kinase 3; enzyme; growth; inhibitor.