Radul, E. | bioRxiv Science

bioRxiv2026

Regulation of microtubule abundance and minus end dynamics by Katanin, CAMSAPs, WDR47 and kinesin-13

Microtubule networks are major determinants of cell architecture and logistics. Microtubule organization and density are regulated by severing enzymes, which cut microtubule lattices or affect their growth and shortening. These activities can lead to microtubule amplification or disassembly, depending on the presence of microtubule stabilizers or destabilizers, but the interplay between these factors is poorly understood. Here, we reconstituted in vitro the activity of microtubule severase katanin together with microtubule minus-end stabilizers CAMSAPs, their binding partner WDR47 and microtubule depolymerase kinesin-13/MCAK. We confirmed that katanin can amplify or destroy microtubules in a concentration-dependent manner. CAMSAPs recruit katanin to microtubules and reduce katanin concentration needed for both amplification and destruction, whereas kinesin-13 completely abolishes microtubule amplification. WDR47 binds to microtubules decorated by CAMSAPs and suppresses katanin binding and severing. In addition, both katanin and WDR47 inhibit polymerization of CAMSAP-decorated microtubule minus ends. These data explain how these proteins act together to fine-tune microtubule minus-end stability without strongly increasing microtubule abundance. O_FIG O_LINKSMALLFIG WIDTH=200 HEIGHT=169 SRC="FIGDIR/small/714132v1_ufig1.gif" ALT="Figure 1"> View larger version (20K): org.highwire.dtl.DTLVardef@746fe3org.highwire.dtl.DTLVardef@5dd5a8org.highwire.dtl.DTLVardef@762373org.highwire.dtl.DTLVardef@1192db_HPS_FORMAT_FIGEXP M_FIG Graphical abstract C_FIG

cell biology↗

bioRxiv2024

Functional genetics reveals modulators of anti-microtubule drug sensitivity

Microtubules play essential roles in diverse cellular processes and are important pharmacological targets for treating human disease. Here, we sought to identify cellular factors that modulate the sensitivity of cells to anti-microtubule drugs. We conducted a genome-wide CRISPR/Cas9-based functional genetics screen in human cells treated with the microtubule-destabilizing drug nocodazole or the microtubule-stabilizing drug taxol. We further conducted a focused secondary screen to test drug sensitivity for [~]1400 gene targets across two distinct human cell lines and to additionally test sensitivity to the Kif11-inhibitor, STLC. These screens defined gene targets whose loss enhances or suppresses sensitivity to anti-microtubule drugs. In addition to gene targets whose loss sensitized cells to multiple compounds, we observed cases of differential sensitivity to specific compounds and differing requirements between cell lines. Our downstream molecular analysis further revealed additional roles for established microtubule-associated proteins and identified new players in microtubule function.

cell biology↗