PT  - JOURNAL ARTICLE
AU  - Hu, Huiqing
AU  - Majneri, Paul
AU  - Li, Dielan
AU  - Kurasawa, Yasuhiro
AU  - An, Tai
AU  - Dong, Gang
AU  - Li, Ziyin
TI  - Functional analyses of the CIF1-CIF2 complex in <em>Trypanosoma brucei</em> identify the structural motifs required for complex formation and cytokinesis
AID  - 10.1101/196238
DP  - 2017 Jan 01
TA  - bioRxiv
PG  - 196238
4099  - http://biorxiv.org/content/early/2017/09/29/196238.short
4100  - http://biorxiv.org/content/early/2017/09/29/196238.full
AB  - Cytokinesis in trypanosome occurs uni-directionally along the longitudinal axis from the cell anterior towards the cell posterior and requires a trypanosome-specific CIF1-CIF2 protein complex. However, little is known about the contribution of the structural motifs in CIF1 and CIF2 to complex assembly and cytokinesis. Here, we demonstrated that the two zinc-finger motifs but not the coiled-coil motif in CIF1 are required for interaction with the EF-hand motifs in CIF2. We further showed that localization of CIF1 depends on the coiled-coil motif and the first zinc-finger motif and that localization of CIF2 depends on the EF-hand motifs. Deletion of the coiled-coil motif and mutation of either zinc-finger motifs in CIF1 disrupted cytokinesis. Further, mutation of either zinc-finger motif in CIF1 mis-localized CIF2 to the cytosol and destabilized CIF2, whereas deletion of the coiled-coil motif in CIF1 spread CIF2 over to the new flagellum attachment zone and stabilized CIF2. Together, these results uncovered the requirement of the coiled-coil motif and zinc-finger motifs for CIF1 function in cytokinesis and for CIF2 localization and stability, providing structural insights into the functional interplay between the two cytokinesis regulators.