Send to

Choose Destination
J Cell Biol. 2019 Dec 2;218(12):4195-4214. doi: 10.1083/jcb.201903152. Epub 2019 Oct 22.

Par-1 controls the composition and growth of cortical actin caps during Drosophila embryo cleavage.

Author information

Department of Cell and Systems Biology, University of Toronto, Toronto, Ontario, Canada.
Department of Cell and Systems Biology, University of Toronto, Toronto, Ontario, Canada


Cell structure depends on the cortex, a thin network of actin polymers and additional proteins underlying the plasma membrane. The cell polarity kinase Par-1 is required for cells to form following syncytial Drosophila embryo development. This requirement stems from Par-1 promoting cortical actin caps that grow into dome-like metaphase compartments for dividing syncytial nuclei. We find the actin caps to be a composite material of Diaphanous (Dia)-based actin bundles interspersed with independently formed, Arp2/3-based actin puncta. Par-1 and Dia colocalize along extended regions of the bundles, and both are required for the bundles and for each other's bundle-like localization, consistent with an actin-dependent self-reinforcement mechanism. Par-1 helps establish or maintain these bundles in a cortical domain with relatively low levels of the canonical formin activator Rho1-GTP. Arp2/3 is required for displacing the bundles away from each other and toward the cap circumference, suggesting interactions between these cytoskeletal components could contribute to the growth of the cap into a metaphase compartment.

[Available on 2020-06-02]

Supplemental Content

Full text links

Icon for Silverchair Information Systems
Loading ...
Support Center