The KIF13A-Rab11a axis: a key regulator of vesicle trafficking in cytokinesis

Cytokinesis requires tightly coordinated membrane trafficking and cytoskeletal remodelling to ensure accurate physical separation of daughter cells. Rab11a, a recycling endosome-associated small GTPase, and KIF13A, a kinesin-3 family microtubule motor protein, have each been implicated in late mitotic events. However, the mechanistic relationship between Rab11a-mediated endosomal trafficking and KIF13A-driven transport during abscission remains insufficiently defined. This study aimed to elucidate the spatial and functional interplay between Rab11a and KIF13A during cytokinesis and to determine the consequences of disrupting this axis on mitotic progression and genomic stability. Rab11a and KIF13A were depleted in HeLa cells using shRNA- and siRNA-mediated knockdown strategies. Subcellular localisation and colocalisation at the intercellular bridge were examined by immunofluorescence microscopy and quantified using Pearson's correlation coefficient. Functional outcomes were assessed through multinucleation, micronuclei formation, telophase accumulation, and LAP2-positive chromatin bridge assays. Mitotic timing from nuclear envelope breakdown to abscission was quantified by live-cell spinning-disk confocal microscopy. Rab11a and KIF13A exhibited pronounced colocalisation at the ICB during cytokinesis. Depletion of either protein reduced its spatial association with the other. It resulted in marked cytokinetic defects, including increased multinucleation, micronuclei formation, telophase delay, and elevated chromatin bridge frequency. Live-cell imaging demonstrated a significant prolongation of the cytokinesis-to-abscission interval, accompanied by an extended overall mitotic M-phase. Mechanistically, loss of Rab11a or KIF13A impaired CHMP4B recruitment to the ICB, reduced PI3P accumulation, and enhanced Aurora B signalling, consistent with activation of the abscission checkpoint. These findings establish the Rab11a-KIF13A axis as a critical regulator of late mitosis, integrating endosomal trafficking with ESCRT-III-dependent abscission. Disruption of this pathway compromises abscission accuracy and promotes genomic instability, highlighting its essential role in maintaining mitotic integrity and its potential relevance in tumorigenesis. Continued exploration of the KIF13A-Rab11 interaction will yield a deeper understanding of mitotic progression and cellular organisation.