New preprint on cargo rotation and motor binding to the microtubule

Say you have two proteins. How long will it take for them to bind to each other?

The answer depends on:

1. Where the proteins start
2. How they move through space
3. How much more favorable the bound configuration is than the unbound configuration

Compared to the unbinding process, which depends only on the third point, binding is way harder to figure out. In the case of the kinesin-1 motor, we know how unbinding works with unparalleled detail, with unbinding investigated under force to the left, right, up, forward, and back. In contrast, binding remains somewhat of a mystery. It has been measured in several scenarios, but it is not clear how to translate between because of points 1 and 2 above.

In this paper, we integrate modeling and measurements of all three to understand the seemingly simple case of a single motor bound to a cargo. Things turn out not so simple indeed, as the binding rate we infer is two orders of magnitude faster than previous estimates.

We also find that changing how the cargo moves by messing with it’s size or the viscosity of the environment around it has a significant impact on binding time, which is an important tie in to my other work.

Find the preprint here: https://www.biorxiv.org/content/10.1101/2020.07.13.201434v1