Biology subjects

Dynlacht, B. D.

Publications and source records attributed to Dynlacht, B. D..

2 recordsLinked to original sources

bioRxiv2023

A mechanism that integrates microtubule motors of opposite polarity at the kinetochore corona

Chromosome biorientation on the mitotic spindle is prerequisite to errorless genome inheritance. CENP-E (kinesin 7) and Dynein-Dynactin (DD), microtubule motors with opposite polarity, promote biorientation from the kinetochore corona, a polymeric structure whose assembly requires MPS1 kinase. The coronas building block consists of ROD, Zwilch, ZW10, and the DD adaptor Spindly (RZZS). How CENP-E and DD are scaffolded and mutually coordinated in the corona remains unclear. Here, we report near-complete depletion of RZZS and DD from kinetochores after depletion of CENP-E and the outer kinetochore protein KNL1. With inhibited MPS1, CENP-E, which we show binds directly to RZZS, is required to retain kinetochore RZZS. An RZZS phosphomimetic mutant bypasses this requirement. With active MPS1, CENP-E is dispensable for corona expansion, but strictly required for physiological kinetochore accumulation of DD. Thus, we identify the corona as an integrated scaffold where CENP-E kinesin controls DD kinetochore loading for coordinated bidirectional transport of chromosome cargo.

cell biology↗

bioRxiv2022

KIF24 controls the clustering of supernumerary centrosomes in pancreatic ductal adenocarcinoma cells

Clustering of supernumerary centrosomes, potentially leading to cell survival and chromosomal instability, is frequently observed in cancers. However, the molecular mechanisms by which centrosome clustering is controlled in cancer cells remain largely unknown. A centrosomal kinesin, KIF24, was previously shown to restrain the assembly of primary cilia in mammalian cells. Here, we revealed that KIF24 depletion suppresses multipolar spindle formation by clustering centrosomes in pancreatic ductal adenocarcinoma (PDAC) cells harboring supernumerary centrosomes. KIF24 depletion also induced hyperproliferation and improved the mitotic progression in PDAC cells. On the other hand, disruption of primary cilia failed to affect the proliferation and spindle formation in KIF24-depleted cells. These results represent a novel role of KIF24 in suppressing centrosome clustering independent of primary ciliation in centrosome-amplified PDAC cells.

cell biology↗