Cell cycle regulation in Trypanosoma brucei

Abstract

Cell division is regulated by intricate and interconnected signal transduction pathways that precisely coordinate, in time and space, the complex series of events involved in replicating and segregating the component parts of the cell. In Trypanosoma brucei, considerable progress has been made over recent years in identifying molecular regulators of the cell cycle and elucidating their functions, although many regulators undoubtedly remain to be identified, and there is still a long way to go with respect to determining signal transduction pathways. However, it is clear that cell cycle regulation in T. brucei is unusual in many respects. Analyses of trypanosome orthologues of conserved eukaryotic cell cycle regulators have demonstrated divergence of their function in the parasite, and a number of other key regulators are missing from T. brucei. Cell cycle regulation differs in different parasite life cycle stages, and T. brucei appears to use different checkpoint control strategies compared to model eukaryotes. It is therefore probable that T. brucei has evolved novel pathways to control its cell cycle.

Fig. 1

Cell cycle regulation in Trypanosoma brucei. Duplication of the major organelles and structures during the cell cycle is illustrated in cartoon format for the PCF. Experimentally verified regulators of G₁ phase are shown in black, basal body duplication in pink, Golgi duplication in green, mitosis in red and cytokinesis in grey. Adapted from .