Biology subjects

Kendrick, A. A.

Publications and source records attributed to Kendrick, A. A..

4 recordsLinked to original sources

bioRxiv2025

Cryo-EM captures early intermediate steps in dynein activation by LIS1

Cytoplasmic dynein-1 (dynein) is an essential molecular motor in eukaryotic cells. Dynein primarily exists in an autoinhibited "Phi" state and requires conformational changes to assemble with its cofactors and form active transport complexes. LIS1, a key dynein regulator, enhances dynein activation and assembly. Using cryo-EM and a human dynein-LIS1 sample incubated with ATP, we mapped the conformational landscape of dynein activation by LIS1. We discovered a novel early intermediate state that we propose precedes our previously identified dynein-LIS1 "Chi" state. Mutations that disrupt this species, which we termed "Pre-Chi", led to motility defects in vitro, emphasizing its functional importance. Together, our findings provide new insights into how LIS1 relieves dynein autoinhibition during the activation pathway.

biophysics↗

bioRxiv2022

Lis1 relieves cytoplasmic dynein-1 auto-inhibition by acting as a molecular wedge

Cytoplasmic dynein-1 transports many intracellular cargos towards microtubule minus ends. Dynein is autoinhibited and undergoes conformational changes to form an active complex, consisting of one or two dynein dimers, the dynactin complex and activating adaptor(s)1,2. The Lissencephaly 1 gene, LIS1, is genetically linked to the dynein pathway from fungi to mammals and is mutated in patients with the neurodevelopmental disease lissencephaly3-5. Lis1 is required for active dynein complexes to form6-10, but how it does so is unclear. Here, we present a structure of two dynein motor domains with two Lis1 dimers wedged in-between. The contact sites between dynein and Lis1 in this structure, termed "Chi", are required for Lis1s regulation of dynein in Saccharomyces cerevisiae in vivo and the formation of active human dynein-dynactin- activating adaptor complexes in vitro. We propose that this structure represents an intermediate in dyneins activation pathway, revealing how Lis1 relieves dyneins autoinhibited state.

cell biology↗

bioRxiv2021

Cytoplasmic dynein-1 cargo diversity is mediated by the combinatorial assembly of FTS-Hook-FHIP complexes

In eukaryotic cells, intracellular components are organized by the microtubule motors cytoplasmic dynein-1 (dynein) and kinesins, which are linked to cargos via adaptor proteins. While [~]40 kinesins transport cargo toward the plus end of microtubules, a single dynein moves cargo in the opposite direction. How dynein transports a wide variety of cargos remains an open question. The FTS-Hook-FHIP ("FHF") cargo adaptor complex links dynein to cargo in mammals and fungi. As human cells have three Hooks and four FHIP proteins, we hypothesized that the combinatorial assembly of different Hook and FHIP proteins could underlie dynein cargo diversity. Using proteomic approaches, we determine the protein interactome of each FHIP protein. Live-cell imaging and biochemical approaches show that different FHF complexes associate with distinct motile cargos. These complexes also move with dynein and its cofactor dynactin in single-molecule in vitro reconstitution assays. Complexes composed of FTS, FHIP1B, and Hook1/Hook3 co-localize with Rab5-tagged early endosomes via a direct interaction between FHIP1B and GTP-bound Rab5. In contrast, complexes composed of FTS, FHIP2A and Hook2 colocalize with Rab1A-tagged ER-to-Golgi cargos and FHIP2A is involved in the motility of Rab1A tubules. Our findings suggest that combinatorial assembly of different FTS-Hook-FHIP complexes is one mechanism dynein uses to achieve cargo specificity.

cell biology↗

bioRxiv2018

HOOK3 is a scaffold for the opposite-polarity microtubule-based motors cytoplasmic dynein and KIF1C

The unidirectional and opposite-polarity microtubule-based motors, dynein and kinesin, drive long-distance intracellular cargo transport. Cellular observations support the existence of mechanisms to couple opposite polarity motors: in cells some cargos rapidly switch directions and kinesin motors can be used to localize dynein. We recently identified an interaction between the cytoplasmic dynein-1 activating adaptor HOOK3 and the kinesin-3 KIF1C. Here we show that KIF1C and dynein/dynactin can exist in a single complex scaffolded by HOOK3. Full-length HOOK3 binds to and activates dynein/dynactin motility. HOOK3 also binds to a short region in the \"tail\" of KIF1C, but unlike dynein/dynactin, this interaction does not affect the processive motility of KIF1C. HOOK3 scaffolding allows dynein to transport KIF1C towards the microtubule minus end, and KIF1C to transport dynein towards the microtubule plus end. We propose that linking dynein and kinesin motors by dynein activating adaptors may be a general mechanism to regulate bidirectional motility.

cell biology↗