Abstract—The single polo like kinase, TbPLK, regulates cytokinesis in Trypanosoma brucei. TbPLK is temporally and spatially regulated through the cell cycle of T. brucei. Temporally, TbPLK emerges in S-phase, maintains its expression in G2/M phase and vanishes in late mitosis through G1 phase. Spatially, TbPLK first appears at posterior end of FAZ, where it co-localizes with basal body, then progresses to the dorsal point of cell at FAZ till reaches the anterior tip of the cell. Even more the ectopic expression of TbPLK is detrimental to growth of procyclic T. brucei cells. Thus TbPLK seems to be a subject to tight control in trypanosome cells. Here, and by using growth curve and flow cytometry assays, cells with TbPLK ectopic expression were found with inhibited growth and cytokinesis with accumulation of cells with multiple nuclei and kinetoplasts. Cell growth and cell cycle progression, however, progress normally when kinase-dead mutant of TbPLK is overexpressed. Careful examination of endogenous TbPLK expression profiles after the two overexpression events, wild-type and kinase-dead mutant, reveals that endogenous protein is stabilized only with overexpression of wild-type protein. Therefore, the stabilized endogenous protein in the background of the overexpressed hyper-catalytic active TbPLK inhibits growth and cell division.
 
Index Terms—Trypanosoma brucei, polo like kinase, cell cycle, overexpression

Cite: Mohamed Bessat, "Overexpression of Trypanosoma brucei Polo Like Kinase TbPLK Inhibits Cytokinesis by Modulating Endogenous Protein Expression," Journal of Medical and Bioengineering, Vol. 3, No. 3, pp. 154-161, September 2014. Doi: 10.12720/jomb.3.3.154-161