The mitotic spindle seems to get all the fun of a microtubule-dynein party, but do not fret. A recent paper describes some cool interactions of microtubules with dynein at the cell’s cortex.
The molecular motor dynein walks along microtubules, and this movement can do great things by moving the microtubules themselves or moving material along the microtubule. Recent work found that dynein at the cell’s cortex may influence cell motility using an actin-independent mechanism that pushes microtubules along the cortex. In an even more recent paper in the journal Molecular Biology of the Cell, this same research group shows these cortical dynein-microtubule interactions directly. Using TIRF microscopy, Mazel and colleagues found speckles of cortical dynein complexes associated with microtubules. These microtubules can move, bend, and even rotate around these speckles. The images above show the difference between wide-field microscopy (left) and TIRFM (right) when imaging microtubules at the cortex. In the bottom panel, a short microtubule can be seen moving directionally.
Tomáš Mazel, Anja Biesemann, Magda Krejczy, Janos Nowald, Olga Müller, & Leif Dehmelt (2014). Direct observation of microtubule pushing by cortical dynein in living cells Molecular Biology of the Cell, 25 (1) DOI: 10.1091/mbc.E13-07-0376