Open Access Research article

The Cryptosporidium parvum Kinome

Jennifer D Artz1*, Amy K Wernimont1, Abdellah Allali-Hassani1, Yong Zhao1, Mehrnaz Amani1, Yu-Hui Lin1, Guillermo Senisterra1, Gregory A Wasney1, Oleg Fedorov2, Oliver King2, Annette Roos2, Vlad V Lunin1, Wei Qiu1, Patrick Finerty1, Ashley Hutchinson1, Irene Chau1, Frank von Delft2, Farrell MacKenzie1, Jocelyne Lew1, Ivona Kozieradzki1, Masoud Vedadi1, Matthieu Schapira1, Chao Zhang3, Kevan Shokat3, Tom Heightman2 and Raymond Hui1

Author Affiliations

1 Structural Genomics Consortium, University of Toronto, MaRS South Tower, Floor 7, 101 College St, Toronto, Ontario M5G 1L7, Canada

2 Structural Genomics Consortium, University of Oxford, Old Road Research Building, Roosevelt Drive, Oxford OX3 7DQ, UK

3 Howard Hughes Medical Institute, Department of Cellular and Molecular Pharmacology, University of California at San Francisco, San Francisco, California 94158, USA

For all author emails, please log on.

BMC Genomics 2011, 12:478  doi:10.1186/1471-2164-12-478

Published: 30 September 2011

Abstract

Background

Hundreds of millions of people are infected with cryptosporidiosis annually, with immunocompromised individuals suffering debilitating symptoms and children in socioeconomically challenged regions at risk of repeated infections. There is currently no effective drug available. In order to facilitate the pursuit of anti-cryptosporidiosis targets and compounds, our study spans the classification of the Cryptosporidium parvum kinome and the structural and biochemical characterization of representatives from the CDPK family and a MAP kinase.

Results

The C. parvum kinome comprises over 70 members, some of which may be promising drug targets. These C. parvum protein kinases include members in the AGC, Atypical, CaMK, CK1, CMGC, and TKL groups; however, almost 35% could only be classified as OPK (other protein kinases). In addition, about 25% of the kinases identified did not have any known orthologues outside of Cryptosporidium spp. Comparison of specific kinases with their Plasmodium falciparum and Toxoplasma gondii orthologues revealed some distinct characteristics within the C. parvum kinome, including potential targets and opportunities for drug design. Structural and biochemical analysis of 4 representatives of the CaMK group and a MAP kinase confirms features that may be exploited in inhibitor design. Indeed, screening CpCDPK1 against a library of kinase inhibitors yielded a set of the pyrazolopyrimidine derivatives (PP1-derivatives) with IC50 values of < 10 nM. The binding of a PP1-derivative is further described by an inhibitor-bound crystal structure of CpCDPK1. In addition, structural analysis of CpCDPK4 identified an unprecedented Zn-finger within the CDPK kinase domain that may have implications for its regulation.

Conclusions

Identification and comparison of the C. parvum protein kinases against other parasitic kinases shows how orthologue- and family-based research can be used to facilitate characterization of promising drug targets and the search for new drugs.