Dynein and neuronal dendrites

Two interesting papers were published in Nature Cell Biology:

Zheng, Y. et al. Dynein is required for polarized dendritic transport and uniform microtubule orientation in axons. Nat Cell Biol 10, 1172-1180(2008).

Satoh, D. et al. Spatial control of branching within dendritic arbors by dynein-dependent transport of Rab5-endosomes. Nat Cell Biol 10, 1164-1171(2008).

Both papers identified that mutations in dynein subunits in Drosophila neurons (da neurons) reduce the extension of dendrites and their branching occurs more proximal to the cell body.

Curiously, Zheng et al observed that in dynein mutants, golgi apparatus markers (ManII-GFP) are localized in the axons, in contrast with wild-type neurons. Furthermore, using two interesting probes for plus-ends (EB1-GFP) and minus-ends (Nod-B-gal, which comprise of the Nod motor domain fused to kinesin-1 coiled-coiled domain, followed by B-galactosidase), these authors show that microtubule organization is changed. In WT axons, microtubules are organized with their plus-ends pointing away from the cell body. In dynein mutants, they observed some microtubules pointing in the opposite direction.

How dynein regulates these processes is still unknown so we will have to wait to find that out.