Dynein

Cytoplasmic dynein uses the energy from ATP hydrolysis to step along microtubule tracks in eukaryotic cells. It is one of the most versatile molecular motors known, with critical roles in powering transport of diverse cargos, constructing the cell division machinery, and polarizing molecules during development. Remarkably, there is just one cytoplasmic dynein responsible for all of its diverse cellular tasks. It therefore relies on interactions with regulating proteins to achieve specificity of function--how this regulation works is a major question in the field and one we have been focused on.

Data from our collaborator’s group (Reck-Peterson lab) and others show that dynein’s motile behavior is altered by Lis1, a ubiquitous dynein co-factor associated with a severe brain development disorder in humans (lissencephaly). We have been using a combination of cryo-EM, molecular modeling, biochemistry and single-molecule assays, to understand at the structural and mechanistic level how Lis1 regulates dynein motility and ultimately how a single dynein can achieve the versatility of function seen in vivo.

In our latest work (see Figure below), we showed that Lis1, a dimer of WD40 domains, can regulate dynein in opposing ways: when a single WD40 is bound to dynein, it induces high-affinity to the microtubule by the motor, while the binding of a second WD40 leads to low-affinity binding. We showed that the nucleotide state of one of dynein's AAA+ domains determines which mode Lis1 adopts and proposed how each mode could serve a different cellular function.

 

Publications

* Equal contribution
# Co-corresponding authors

DeSantis ME*, Cianfrocco MA*, Htet ZM*, Tran PT, Reck-Peterson SL# and Leschziner AE# (2017). Lis1 has two opposing modes of regulating cytoplasmic dynein. Cell 170:1197-1201

Cianfrocco MA*, DeSantis ME*, Leschziner AE and Reck-Peterson SL (2015). Mechanism and regulation of cytoplasmic dynein. Annu. Rev. Cell. Dev. Biol. 31:83-108

Toropova K*, Zou S*, Roberts AJ, Redwine WB, Goodman BS, Reck-Peterson SL#, Leschziner AE# (2014). Lis1 regulates dynein by sterically blocking its mechanochemical cycle. eLIFE: 03372 (link)

Cianfrocco MA, Leschziner AE (2014).Traffic control: adaptor proteins guide dynein-cargo takeoff. EMBO J 33:1845-6 [News & Views]

Derr ND*, Goodman BS*, Jungmann R, Leschziner AE, Shih WM, Reck-Peterson SL (2012). Tug-of-war in motor protein ensembles revealed with a programmable DNA origami scaffold. Science 338:662-5 {download PDF}

Redwine WB*, Hernandez-Lopez R*, Zou S, Huang J, Reck-Peterson SL, Leschziner AE (2012). Structural basis for microtubule binding and release by dynein. Science 337:1532-1536 {download PDF}{Supplemental movies}

Huang J*, Roberts A*, Leschziner AE, Reck-Peterson SL (2012). Lis1 acts as a "clutch" between the ATPase and microtubule-binding domains of the dynein motor. Cell 150:975-986 {download PDF}

 
  Lis1 regulates dynein in opposing ways.  Lis1 can regulate dynein in opposing ways by binding either one or two WD40s to the motor. This binding is regulated by the nucleotide state of dynein's AAA3 (top diagram). When AAA3 has no nucleotide, a single WD40 binds at AAA4 and induces high affinity for the microtubule. When AAA3 contains ATP, a second WD40 binds to dynein's stalk (as well as to the other WD40) and this state induces low affinity for the microtubule. The cryo-EM structures of the two states (with atomic models fitted in) are shown bottom left (one WD40 bound) and bottom right (two WD40s bound).

Lis1 regulates dynein in opposing ways. Lis1 can regulate dynein in opposing ways by binding either one or two WD40s to the motor. This binding is regulated by the nucleotide state of dynein's AAA3 (top diagram). When AAA3 has no nucleotide, a single WD40 binds at AAA4 and induces high affinity for the microtubule. When AAA3 contains ATP, a second WD40 binds to dynein's stalk (as well as to the other WD40) and this state induces low affinity for the microtubule. The cryo-EM structures of the two states (with atomic models fitted in) are shown bottom left (one WD40 bound) and bottom right (two WD40s bound).