MSc Exit Seminar – Jin Meng (Godt Lab)

Actin filaments (F-actin) are essential for many cellular functions. Their dynamic remodeling allows various processes, including cell division, cell adhesion, cell polarization, and formation of stress fibres and cellular protrusions. One factor contributing to actin remodeling is Actin-interacting protein 1 (AIP1), a cofactor for cofilin in F-actin depolymerization. I used the Drosophila follicular epithelium to investigate the function of AIP1 in regulating the actin cytoskeleton and associated structures. AIP1 depletion caused an increase in F-actin amounts in the apical cytocortex and ectopic globular F-actin aggregates. Additionally, it resulted in microvilli of altered length, extended basal stress fibres, and defects in the distribution of adherens junction components and the spectrin cytoskeleton. Moreover, AIP1 reduction led to nuclear enlargement and multi-nucleation in follicle cells, suggesting defects during cytokinesis. These findings suggest that AIP1-mediated actin turnover is critical for normal actin organization, which is important for cellular protrusions, cell adhesion, and cell division.