The goal of the lab is to understand how cells divide and we use human cancer cells and the C. elegans embryo as model systems. Watch the video to learn more about our research:
Positioning the contractile ring
During cytokines signals from the mitotic spindle position the contractile ring at the right place. A stimulatory signal from the spindle midzone promotes contractile ring assembly in the center and an inhibitory signal from the microtubule asters prevents ring assembly at the cell poles. We dissected the molecular mechanism of the stimulatory signal and showed that the activity of GEF Ect2 is controlled by a multilayers mechanism (Schneid et al., Cell Reports 2021). With a second research line we identified for the first time the molecular players of the inhibitory signal in animal cells and demonstrated that Aurora A kinase activates the RhoA GAP MP-GAP at the cell poles (Mangal et al. Journal of Cell Biology 2018, Wolff et al., BioRxive 2023).
Contractile ring assembly
and constriction
The contractile ring consists of actin filaments and the motor myosin II which form a contractile network and mediate constriction. We discovered a compensatory mechanism that mediates ring constrictions when actin levels are low. We found that the multidomain protein anillin forms filamentous structures and mediates ring ingression together with myosin II when actin polymerization is defective (Lebedev et al., Cell Reports 2023).
In many animal cells the ring constricts asymmetrically with one side ingressing faster than the opposite side. We discovered that anillin mediates asymmetric ring ingression by controlling the activity of the small GTPase RhoA (Lebedev et al., Journal Cell Biology 2025 ).
Light-controllable molecules to control cellular functions
Biological processes are highly dynamic and to study and manipulate them one requires tools with high spatial and temporal precision. In collaboration with the group of Henry Dube we developed a light-controllable proteasome and kinase inhibitors inhibitors, which allows us to manipulate cellular function with light (Uhl et al., Angewandte Chemie 2021, Köttner et al., JACS 2024). Those light-controllable molecules are not only outstanding tools for biological research question but hold also great promise in the future to treat disease such as cancer with light.