Dynein

Active transport along microtubules by molecular motors is a crucial cellular process that is disrupted in human diseases. Single-molecule studies from three independent groups reveal a new molecular mechanism for how cells control the activity of the complex microtubule motor cytoplasmic dynein via the neurodevelopmental protein LIS1.

Roop Mallik argues for the importance of considering the impact that membrane lipids have on motors, and the dynamics of the membrane–motor interface, in studies of cytoskeletal motors.

Researchers have sought to understand the function and regulation of the motor protein dynein since its discovery more than 50 years ago¹. Dynein-2 is one of the motors that move the intraflagellar transport (IFT) trains ― large protein complexes that are needed for the assembly and function of eukaryotic cilia and flagella. Toropova et al. report the single-particle cryo-EM structure of the human dynein-2 complex², which unexpectedly reveals two different conformations of the motor subunit tails. One tail forms a zigzag that matches the periodicity of the IFT trains, which reinforces the auto-inhibition of dynein motor activity and the binding of multiple dynein-2 complexes along the train during anterograde transport.

Dynactin is an essential cofactor for the microtubule-based motor cytoplasmic dynein. Two recent papers report structures obtained by cryo-EM of dynactin, the dynein–dynactin complex and dynein–dynactin bound to its track, the microtubule.

Control of the activity of the microtubule motor cytoplasmic dynein 1 is essential for its function in intracellular transport. A recent paper by McKenney et al. published in Science shows that activation of processive dynein motility requires the formation of cargo adaptor-dynein-dynactin complexes.

Two fungal Hook proteins are identified as recruiting motor proteins to early endosomes for microtubule-based transport.