Conditional Degradation of Plasmodium Calcineurin Reveals Functions in Parasite Colonization of both Host and Vector

Summary

Functional analysis of essential genes in the malarial parasite, Plasmodium, is hindered by lack of efficient strategies for conditional protein regulation. We report the development of a rapid, specific, and inducible chemical-genetic tool in the rodent malaria parasite, P. berghei, in which endogenous proteins engineered to contain the auxin-inducible degron (AID) are selectively degraded upon adding auxin. Application of AID to the calcium-regulated protein phosphatase, calcineurin, revealed functions in host and vector stages of parasite development. Whereas depletion of calcineurin in late-stage schizonts demonstrated its critical role in erythrocyte attachment and invasion in vivo, stage-specific depletion uncovered roles in gamete development, fertilization, and ookinete-to-oocyst and sporozoite-to-liver stage transitions. Furthermore, AID technology facilitated concurrent generation and phenotyping of transgenic lines, allowing multiple lines to be assessed simultaneously with significant reductions in animal use. This study highlights the broad applicability of AID for functional analysis of proteins across the Plasmodium life cycle.

Graphical Abstract

Highlights

• •

  Calcineurin regulates colonization of host cells across the Plasmodium life cycle

• •

  Calcineurin regulates male gametogenesis

• •

  AID technology is broadly applicable to study protein function in Plasmodium

• •

  Multiplexing of AID technology results in substantially reduced animal use

Abstract

Limited conditional regulation technologies in the malarial parasite, Plasmodium, hinder functional examination of parasite proteins operating at multiple stages. Philip and Waters report the application of a rapid and specific conditional protein degradation tool to study parasite Calcineurin function in both host and vector stages of the parasite life cycle.