Teamwork in microtubule motors

• Can cell mechanics be understood in terms of the molecules that generate force?
• How does single-molecule function of motors translate into their collective cellular function?.
• Surprising reversal of roles: ‘good’ motors fail, but ‘bad’ motors excel as a team.
• Dynein's gear-like response and catch bond may adapt it to work well in a team.

Diverse cellular processes are driven by the collective force from multiple motor proteins. Disease-causing mutations cause aberrant function of motors, but the impact is observed at a cellular level and beyond, therefore necessitating an understanding of cell mechanics at the level of motor molecules. One way to do this is by measuring the force generated by ensembles of motors in vivo at single-motor resolution. This has been possible for microtubule motor teams that transport intracellular organelles, revealing unexpected differences between collective and single-molecule function. Here we review how the biophysical properties of single motors, and differences therein, may translate into collective motor function during organelle transport and perhaps in other processes outside transport.