Image of the Day: Actin Assembly

Microtubules need actin to disassemble focal adhesions, allowing for cell movement.

Emily Makowski
Sep 17, 2019

Cell migration depends on structures called focal adhesions that connect a cell to the surrounding extracellular matrix. Microtubules—long, thin polymers found in and around cells—help disassemble focal adhesions, allowing the cell to move. A study published August 30 in the Journal of Cell Biology found that the protein actin is necessary for normal feedback between microtubules and focal adhesions. 

The researchers, led by M. Angeles Juanes of Brandeis University, studied motile breast cancer cells. The video above shows time-lapse fluorescence microscopy of migrating breast cancer cells. As the cells move, focal adhesions (the brighter pink areas) assemble and disassemble. Wildtype cells (left) had faster focal adhesion disassembly than cells that had a defect in forming actin filaments (right), suggesting that actin helps maintain the dynamics and organization of microtubules and other focal adhesion components. 

M. A. Juanes et al., “The role of APC-mediated actin assembly in microtubule capture and focal adhesion turnover,” doi/10.1083/jcb.201904165, J Cell Biol, 2019.

Emily Makowski is an intern at The Scientist. Email her at