Structural Basis for Cytoplasmic Dynein-1 Regulation by Lis1

Abstract

The lissencephaly 1 gene, LIS1, is mutated in patients with the neurodevelopmental disease lissencephaly. The Lis1 protein is conserved from fungi to mammals and is a key regulator of cytoplasmic dynein-1, the major minus-end-directed microtubule motor in many eukaryotes. Lis1 is the only dynein regulator that binds directly to dynein's motor domain, and by doing so alters dynein's mechanochemistry. Lis1 is required for the formation of fully active dynein complexes, which also contain essential cofactors: dynactin and an activating adaptor. Here, we report the first high-resolution structure of the yeast dynein-Lis1 complex. Our 3.1Å structure reveals, in molecular detail, the major contacts between dynein and Lis1 and between Lis1's β-propellers. Structure-guided mutations in Lis1 and dynein show that these contacts are required for Lis1's ability to form fully active human dynein complexes and to regulate yeast dynein's mechanochemistry and in vivo function. We present a model for the conserved role of Lis1 in regulating dynein from yeast to humans.

Lis1 binding regulates force-induced detachment of cytoplasmic dynein from microtubules

“…Consistent with previous reports 13, 15, 16 , these results indicate that Lis1 binding increases the microtubule binding affinity of dynein. Mutagenesis of the Lis1 interaction site on dynein’s stalk in dynein EQN did not recover dynein velocity, demonstrating that Lis1’s interaction with the AAA+ ring is primarily responsible for slower movement 15, 16 . These results are consistent with a model in which Lis1 binding to the AAA+ ring prevents nucleotide-induced rigid body motions of the AAA+ subunits and traps the AAA+ ring in the high microtubule affinity conformation 15 , resulting in a slower velocity.…”

“…Because Lis1 increases the microtubule affinity of dynein (Fig. 1) 13,15,16 , we also tested whether Lis1 binding slows dynein motility by altering the detachment kinetics of dynein from the microtubule. Nucleotide hydrolysis in dynein's AAA+ ring controls its microtubule affinity by altering the registry of the stalk coiled coils [39][40][41] .…”

“…Lis1 was also shown to interact with the coiled-coil stalk of dynein when the AAA3 site is trapped in the ATP-bound state, and this interaction induces a lower microtubule affinity state 15 . Structure-guided mutations showed that the Lis1-stalk interaction is important for the localization of dynein to the cortex of yeast cells 15, 16 . However, it remains to be determined how the Lis1-stalk interaction affects the mechanism of dynein motility.…”

Lis1-dynein drives corona compaction and error-correction at kinetochores

“…Thus, it is possible that a myriad of complex Lis1-dynein interactions tailor the motor’s functionality. In support of this, the Lis1 stalk is dispensable for microtubule plus-end localisation but necessary for cortical and spindle pole body association in yeast (Gillies et al, 2022). Our data establishes Lis1-5A as another separation-of-function mutant (and the first in humans) that may be a useful tool to further our understanding of Lis1-mediated dynein regulation.…”

“…Precisely how mutation of these five residues alter Lis1-dynein binding and/or mechanochemistry is unclear. During preparation of this manuscript the high-resolution structure of the yeast Lis1(Pac1)-dynein complex was reported, which revealed additional dynein contacts in the Lis1 propeller and detailed how the Lis1 stalk interacts with dynein (Gillies et al, 2022). Moreover, this study found that human Lis1 likely contains additional contacts required for dynein regulation.…”