Mutant/mutation
The mutant expresses a C-terminal 2xmyc-tagged version of CDPK4 (and is drug-selectable marker free).

Protein (function)
CDPK4 belongs to an expanded family of Ca²⁺ dependent protein kinases (CDPKs). CDPKs combine an amino-terminal serine/threonine kinase domain and a carboxy-terminal calmodulin-like domain, composed of four EF hands, in the same molecule. In plants, CDPKs translate Ca²⁺ signals generated by external stimuli into cellular responses, thereby regulating cell division and differentiation, the development of tolerance to stress stimuli and the specific defense responses to pathogens.

CDPK4 plays a role in male gamete formation after activation of male gametes. It plays a role in male gametocytes axoneme formation, formation of mitotic spindles and DNA synthesis. Evidence has been presented for an additional role in sporozoites: reduced invasion of hepatocytes (RMgm-1510).  See PF3D7_0717500 for other CDPK4 mutants

Phenotype
Evidence is presented that the myc tag did not affect the function of CDPK4 during exflagellation. This mutant has been used for co-immunoprecipitation and localisation experiments. CDPK4 showed a broad cellular distribution in microgametocytes at 0 and 15 seconds after activation.

Additional information
A total of 150 proteins were immunoprecipitated in both CDPK4-3xHA and CDPK4-2xmyc lysates after cross-linking but not in a WT control. MCM2-7/Cdt1 and ORC proteins that are part of the pre-replicative complex represented the most enriched molecular components. Proteins of the microtubule cytoskeleton and of the replisome were also enriched including polymerases α, δ, and ε, the proliferating nuclear antigen, replication factor C complexes and replication factor A.

Other mutants
See PF3D7_0717500 for other CDPK4 mutants