bioRxiv Science⌕ Search

Biology subjects

Gupta-Rossi, N.

Publications and source records attributed to Gupta-Rossi, N..

2 recordsLinked to original sources

Cut-Detector: A Tool for Automated Temporal Analysis of Late Cytokinetic Events

Cytokinesis is the final step of cell division, resulting in the physical separation of the two daughter cells. Despite its fundamental importance in cell biology, biologists currently lack automatic tools for large-scale profiling of cytokinesis dynamics. In particular, the timing of the first microtubule cut in the intercellular bridge connecting the daughter cells is crucial, as it marks a critical step preceding abscission. Here, we introduce Cut-Detector, an open-source tool for the automatic analysis of late cytokinesis timing from time-lapse microscopy movies. Cut-Detector employs an AI approach to carry out the multiple tasks required to monitor cytokinesis: cell segmentation and tracking, detection of cell division events, localization of the intercellular bridge, and detection of the microtubule cuts. Cut-Detector will facilitate large-scale analyses to uncover new cytokinetic genes, a task that would be impractical without automation.

bioinformatics↗

The Flemmingsome reveals an ESCRT-to-membrane coupling required for completion of cytokinesis

Cytokinesis requires the constriction of ESCRT-III filaments on the side of the midbody, where abscission occurs. After ESCRT recruitment at the midbody, it is not known how the ESCRT-III machinery localizes to the abscission site. To reveal novel actors involved in abscission, we obtained the proteome of intact, post-abscission midbodies (Flemmingsome) and identified 489 proteins enriched in this organelle. Among those proteins, we further characterized a plasma membrane-to-ESCRT module composed of the transmembrane proteoglycan syndecan-4, ALIX and syntenin, a protein that bridges ESCRT-III/ALIX to syndecans. The three proteins were highly recruited first at the midbody then at the abscission site, and their depletion delayed abscission. Mechanistically, direct interactions between ALIX, syntenin and syndecan-4 were essential for proper enrichment of the ESCRT-III machinery at the abscission site, but not at the midbody. We propose that the ESCRT-III machinery must be physically coupled to a membrane protein at the cytokinetic abscission site for efficient scission, revealing novel common requirements in cytokinesis, exosome formation and HIV budding.

cell biology↗