AUTHOR=Zhang Qiang , Shao Qian , Guo Yaqiong , Li Na , Li Yu , Su Jiayuan , Xu Rui , Zhang Ziding , Xiao Lihua , Feng Yaoyu 

TITLE=Characterization of Three Calcium-Dependent Protein Kinases of Cryptosporidium parvum

JOURNAL=Frontiers in Microbiology

VOLUME=Volume 11 - 2020

YEAR=2021

URL=https://www.frontiersin.org/journals/microbiology/articles/10.3389/fmicb.2020.622203

DOI=10.3389/fmicb.2020.622203

ISSN=1664-302X

ABSTRACT=In Cryptosporidium spp., calcium-dependent protein kinases (CDPKs) are considered promising targets for the development of pharmaceutical interventions. Whole-genome sequencing has revealed the presence of 11 CDPKs in Cryptosporidium parvum (CpCDPKs). In this study, we expressed recombinant CpCDPK4, CpCDPK5 and CpCDPK6 in Escherichia coli. The biological characteristics and functions of these CpCDPKs were examined by using qRT-PCR, immunofluorescence microscopy, and an in vitro neutralization assay. The expression of the CpCDPK4 gene peaked at 12 h post-infection, the CpCDPK5 gene at 12 h and 48 h, and the CpCDPK6 gene at 2-6 h. CpCDPK4 protein was located in the anterior and mid-anterior regions of sporozoites, CpCDPK5 over the entire sporozoites, while CpCDPK6 was expressed in a spotty pattern. Immune sera of CpCDPK4 and CpCDPK6 exhibited significant inhibitory effects on host cell invasion, while the immune sera of CpCDPK5 had no effects. These differences in protein localization, gene expressions and neutralizing capacities indicated that the CpCDPK proteins may have different roles during the lifecycle of Cryptosporidium spp.