Cryo-electron tomography reveals that dynactin recruits a team of dyneins for processive motility

Grotjahn, Danielle A.; Chowdhury, Saikat; Xu, Yuntao; McKenney, Richard J.; Schroer, Trina A.; Lander, Gabriel C.

doi:10.1038/s41594-018-0027-7

Cited by 131 publications

(151 citation statements)

References 37 publications

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“…Members of the BicD family, BicD2 and BicDR1, are well-characterized coiled-coil adaptors that link dynein to Golgi-derived Rab6 vesicles, as well as nuclear pore complexes and viruses 31,33,34 . Structural studies showed that BicDR1 recruits two dyneins to dynactin, while the N-terminal coiled-coil domain of BicD2 (BiCD2N) mostly recruits a single dynein 35,36 . The increased probability of recruiting two dyneins per dynactin results in complexes assembled with…”

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confidence: 99%

Lis1 activates dynein motility by pairing it with dynactin

Elshenawy

Kusakci

Volz

et al. 2019

Preprint

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Lissencephaly-1 (Lis1) is a key cofactor for dynein-mediated intracellular transport towards the minusends of microtubules (MTs). It remains unclear whether Lis1 serves as an inhibitor or an activator of mammalian dynein motility. Here we use single-molecule imaging and optical trapping to show that Lis1 does not directly alter the stepping and force production of individual dynein motors assembled with dynactin and a cargo adaptor. Instead, Lis1 binding releases dynein from its auto-inhibited state and thereby promotes the formation of an active complex with dynactin. Lis1 also favors recruitment of two dyneins to dynactin, resulting in increased velocity, higher force production and more effective competition against kinesin in a tug-of-war. Lis1 dissociates from motile complexes, indicating that its primary role is to orchestrate the assembly of the transport machinery. These results provide a mechanistic explanation for why Lis1 is required for efficient transport of many dynein-associated cargoes in cells.Cytoplasmic dynein (dynein hereafter) is an AAA+ motor responsible for nearly all motility and force generation towards the microtubule minus-end 1-3 . Dynein is involved in a wide variety of cellular functions, such as positioning of intracellular organelles, breakdown of the nuclear envelope and assembly of the mitotic spindle during mitosis 4-6 . The partial loss of dynein function has been implicated in a range of neurogenerative and neurodevelopmental conditions, including spinal muscular atrophy, amyotrophic lateral sclerosis, Alzheimer's disease and schizophrenia 7-9 .The dynein complex (1.4 MDa) is a homodimer of two heavy chains, which recruit smaller associated polypeptides 10 . The C-terminal motor domain of the heavy chain is a catalytic ring of six AAA modules (AAA1-6). ATPase activity at AAA1 powers dynein motility 11, 12 , while AAA3 regulates MT attachment and force generation cycles [13][14][15] . In contrast to kinesin, whose MT interface is located on the surface of the ATPase core, dynein's MTBD is separated from the catalytic domain by a coiled-coil stalk 16 . Nucleotidedependent conformational changes of the linker drive the motility towards the MT minus-end 17, 18 . The tail domain dimerizes the heavy chains 19-21 , and binds a light intermediate chain (LIC) and an intermediate chain (IC) complexed with three light chains (LCs: LC7, LC8 and Tctex) 1, 22, 23 .When dynein is not bound to its cargo, it forms two distinct conformations, the phi-particle and open conformation, both of which move poorly along MTs 24, 25 . In the phi conformation, two motor domains self-dimerize through interactions between their linker, AAA+ ring and stalk regions and weakly interact with MTs. In the open conformation, the motor domains are more flexible and point towards each other, which is unfavorable for processive motility 24,26 . Dynein interacts with its activating cofactor dynactin and binds to its cellular cargos in the open conformation. Transitions between the phi and open conformation are propos...

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confidence: 99%

Lis1 activates dynein motility by pairing it with dynactin

Elshenawy

Kusakci

Volz

et al. 2019

Preprint

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“…Activated human dynein is a large ~4MDa multi-subunit complex composed of one or two dynein dimers (each dynein dimer contains two motor subunits and two copies each of five additional subunits), the dynactin complex (composed of 23 polypeptides) and one of several classes of dimeric, coiled-coilcontaining activating adaptors (Fig. 1a) [2][3][4][5][6]9 . The dynein motor-containing subunit, or heavy chain, is an ATPase containing six AAA+ domains and a microtubule-binding domain that emerges from a long coiled-coil "stalk" (Fig.…”

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confidence: 99%

Lis1 promotes the formation of maximally activated cytoplasmic dynein-1 complexes

Htet

Gillies

Baker

et al. 2019

Preprint

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Cytoplasmic dynein-1 is a molecular motor that drives nearly all minus-end-directed microtubule-based transport in human cells, performing functions ranging from retrograde axonal transport to mitotic spindle assembly 1,2 . Activated dynein complexes consist of one or two dynein dimers, the dynactin complex, and an "activating adaptor", with maximal velocity seen with two dimers present ( Fig. 1a) 3-6 . Little is known about how this massive ~4MDa complex is assembled. Using purified recombinant human proteins, we uncovered a novel role for the dynein-binding protein, Lis1, in the formation of fully activated dynein complexes containing two dynein dimers. Lis1 is required for maximal velocity of complexes activated by proteins representing three different families of activating adaptors: BicD2, Hook3, and Ninl. Once activated dynein complexes have formed, they do not require the presence of Lis1 for sustained maximal velocity. Using cryo-electron microscopy we show that human Lis1 binds to dynein at two sites on dynein's motor domain, similar to yeast dynein 7 . We propose that the ability of Lis1 to bind at these sites may function in multiple stages of assembling the motile human dynein/ dynactin/ activating adaptor complex.

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“…For example, recent experimental observations show how dynactin recruits two dimeric dyneins for faster movement, supporting the notion that dynein stepping patterns on microtubules could be influenced by such cofactors [28,29]. The emerging evidence on the structure and function of dynein-dynactin are providing growing insight into how these two act together to carry cargos [2,28–33].…”

Section: Introductionmentioning

confidence: 89%

A mathematical understanding of how cytoplasmic dynein walks on microtubules

2018

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Cytoplasmic dynein 1 (hereafter referred to simply as dynein) is a dimeric motor protein that walks and transports intracellular cargos towards the minus end of microtubules. In this article, we formulate, based on physical principles, a mechanical model to describe the stepping behaviour of cytoplasmic dynein walking on microtubules from the cell membrane towards the nucleus. Unlike previous studies on physical models of this nature, we base our formulation on the whole structure of dynein to include the temporal dynamics of the individual subunits such as the cargo (for example, an endosome, vesicle or bead), two rings of six ATPase domains associated with diverse cellular activities (AAA+ rings) and the microtubule-binding domains which allow dynein to bind to microtubules. This mathematical framework allows us to examine experimental observations on dynein across a wide range of different species, as well as being able to make predictions on the temporal behaviour of the individual components of dynein not currently experimentally measured. Furthermore, we extend the model framework to include backward stepping, variable step size and dwelling. The power of our model is in its predictive nature; first it reflects recent experimental observations that dynein walks on microtubules using a weakly coordinated stepping pattern with predominantly not passing steps. Second, the model predicts that interhead coordination in the ATP cycle of cytoplasmic dynein is important in order to obtain the alternating stepping patterns and long run lengths seen in experiments.

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Cryo-electron tomography reveals that dynactin recruits a team of dyneins for processive motility

Cited by 131 publications

References 37 publications

Lis1 activates dynein motility by pairing it with dynactin

Lis1 activates dynein motility by pairing it with dynactin

Lis1 promotes the formation of maximally activated cytoplasmic dynein-1 complexes

A mathematical understanding of how cytoplasmic dynein walks on microtubules

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