Wallis, S. S. | Search bioRxiv

bioRxiv2025

The RNA-binding protein RSRC2 promotes mitotic fidelity by interacting with the lncRNA C1QTNF1-AS1

Mitotic fidelity depends on proper chromosome alignment at the spindle equator, a process known as chromosome congression, driven by well-established protein networks. Whereas RNA-binding proteins and noncoding RNAs have been implicated in cell division, their interplay during this process remains unknown. Here, we discover that RSRC2, an arginine/serine-rich RNA-binding protein, plays an essential role in cell division by interacting with the long non-coding RNA C1QTNF1-AS1. The loss of either RSRC2 or C1QTNF1-AS1 results in defects in chromosome congression and mitotic progression. We show that RSRC2 interacts with distinct sets of proteins involved in splicing and centrosome biogenesis, contributing to the fidelity of cell division through two different mechanisms: one linked to the splicing of mitotic regulators and the other by localising to mitotic centrosomes for which the interaction with the C1QTNF1-AS1 RNA is required. Our study uncovers RSRC2 as a new regulator of cell division and illustrates how RNA-protein complexes promote error-free mitosis.

cell biology↗

bioRxiv2022

Centrosome amplification fine-tunes tubulin acetylation to differentially control intracellular organization

Intracellular organelle organisation is conserved in eukaryotic cells and is primarily achieved through active transport by motor proteins along the microtubule cytoskeleton. Microtubule posttranslational modifications (PTMs) contribute to microtubule diversity and differentially regulate motor-mediated transport. Here we show that centrosome amplification induces a global change in organelle positioning towards the cell periphery and facilitates nuclear migration through confined spaces. This reorganisation requires kinesin-1 and is analogous to loss of dynein. Cells with amplified centrosomes display increased levels of acetylated tubulin, a PTM known to enhance kinesin-1 mediated transport. Depletion of -tubulin acetyltransferase 1 (TAT1) to block tubulin acetylation, which has no impact on control cells, rescues the displacement of centrosomes, mitochondria and vimentin, but not Golgi or endosomes. Analyses of the distribution of acetylated microtubules indicates that the polarisation of modified microtubules, rather than levels alone, plays an important role in organelle positioning. We propose that tubulin acetylation differentially impacts kinesin-1-mediated organelle displacement, suggesting that each organelle must have its own sensing and response mechanisms to ensure fine-tuning of its distribution in cells.

cell biology↗