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Current Biology : CB Dec 2023Dyneins are a family of motor proteins that carry out motility and force generation functions towards the minus end of microtubule filaments. Cytoplasmic dynein...
Dyneins are a family of motor proteins that carry out motility and force generation functions towards the minus end of microtubule filaments. Cytoplasmic dynein (dynein-1) is responsible for transporting intracellular cargos in the retrograde direction in the cytoplasm, anchoring several organelles to the microtubule network, driving nuclear migration in developing neurons, and orienting the mitotic spindle in dividing cells. All other dyneins are localized to cilia. Similar to dynein-1, dynein-2 walks along microtubules and drives intraflagellar transport in the retrograde direction. Other ciliary dyneins are positioned between adjacent microtubule doublets of the axoneme and power ciliary beating by sliding microtubules relative to each other. In this primer, we first highlight the structure, mechanism, and regulation of dynein-1, which is the best-characterized member of the dynein motor family, and then describe the unique features and cellular roles of other dyneins. We also discuss accessory proteins that regulate the activation and motility of dynein motors in different cellular contexts.
Topics: Dyneins; Microtubules; Axoneme; Kinesins; Spindle Apparatus
PubMed: 38113834
DOI: 10.1016/j.cub.2023.10.064 -
The Journal of Cell Biology Apr 2024Centrosomes are the primary microtubule organizer in eukaryotic cells. In addition to shaping the intracellular microtubule network and the mitotic spindle, centrosomes... (Review)
Review
Centrosomes are the primary microtubule organizer in eukaryotic cells. In addition to shaping the intracellular microtubule network and the mitotic spindle, centrosomes are responsible for positioning cilia and flagella. To fulfill these diverse functions, centrosomes must be properly located within cells, which requires that they undergo intracellular transport. Importantly, centrosome mispositioning has been linked to ciliopathies, cancer, and infertility. The mechanisms by which centrosomes migrate are diverse and context dependent. In many cells, centrosomes move via indirect motor transport, whereby centrosomal microtubules engage anchored motor proteins that exert forces on those microtubules, resulting in centrosome movement. However, in some cases, centrosomes move via direct motor transport, whereby the centrosome or centriole functions as cargo that directly binds molecular motors which then walk on stationary microtubules. In this review, we summarize the mechanisms of centrosome motility and the consequences of centrosome mispositioning and identify key questions that remain to be addressed.
Topics: Biological Transport; Centrioles; Centrosome; Microtubules; Spindle Apparatus; Cilia; Humans; Animals; Dyneins
PubMed: 38512059
DOI: 10.1083/jcb.202311140 -
Journal of Biochemistry Apr 2024Mysterin is a large intracellular protein harboring a RING finger ubiquitin ligase domain and is also referred to as RING finger protein 213 (RNF213). The author... (Review)
Review
Mysterin is a large intracellular protein harboring a RING finger ubiquitin ligase domain and is also referred to as RING finger protein 213 (RNF213). The author performed the first molecular cloning of the mysterin gene as the final step in genetic exploration of cerebrovascular moyamoya disease (MMD) and initiated the next round of exploration to understand its molecular and cellular functions. Although much remains unknown, accumulating findings suggest that mysterin functions in cells by targeting massive intracellular structures, such as lipid droplets (LDs) and various invasive pathogens. In the latter case, mysterin appears to directly surround and ubiquitylate the surface of pathogens and stimulate cell-autonomous antimicrobial reactions, such as xenophagy and inflammatory response. To date, multiple mutations causing MMD have been identified within and near the RING finger domain of mysterin; however, their functional relevance remains largely unknown. Besides the RING finger, mysterin harbors a dynein-like ATPase core and an RZ finger, another ubiquitin ligase domain unique to mysterin, while functional exploration of these domains has also just commenced. In this review, the author attempts to summarize the core findings regarding the molecular structure and function of the mysterin protein, with an emphasis on the perspective of MMD research.
Topics: Humans; Ubiquitin-Protein Ligases; Animals; Moyamoya Disease; Adenosine Triphosphatases
PubMed: 38378744
DOI: 10.1093/jb/mvae020 -
The EMBO Journal Aug 2023Intracellular organelle organization is conserved in eukaryotic cells and is primarily achieved through active transport by motor proteins along the microtubule...
Intracellular organelle organization is conserved in eukaryotic cells and is primarily achieved through active transport by motor proteins along the microtubule cytoskeleton. Microtubule post-translational modifications (PTMs) can contribute to microtubule diversity and differentially regulate motor-mediated transport. Here, we show that centrosome amplification, commonly observed in cancer and shown to promote aneuploidy and invasion, induces a global change in organelle positioning towards the cell periphery and facilitates nuclear migration through confined spaces. This reorganization requires kinesin-1 and is analogous to the loss of dynein. Cells with amplified centrosomes display increased levels of acetylated tubulin, a PTM that could enhance kinesin-1-mediated transport. Depletion of α-tubulin acetyltransferase 1 (αTAT1) to block tubulin acetylation rescues the displacement of centrosomes, mitochondria, and vimentin but not Golgi or endosomes. Analyses of the distribution of total and acetylated microtubules indicate that the polarized distribution of modified microtubules, rather than levels alone, plays an important role in the positioning of specific organelles, such as the centrosome. We propose that increased tubulin acetylation differentially impacts kinesin-1-mediated organelle displacement to regulate intracellular organization.
Topics: Tubulin; Kinesins; Acetylation; Microtubules; Centrosome; Dyneins; Protein Processing, Post-Translational
PubMed: 37403793
DOI: 10.15252/embj.2022112812 -
Nature Structural & Molecular Biology Sep 2023Cytoplasmic dynein-1 transports intracellular cargo towards microtubule minus ends. Dynein is autoinhibited and undergoes conformational changes to form an active...
Cytoplasmic dynein-1 transports intracellular cargo towards microtubule minus ends. Dynein is autoinhibited and undergoes conformational changes to form an active complex that consists of one or two dynein dimers, the dynactin complex, and activating adapter(s). The Lissencephaly 1 gene, LIS1, is genetically linked to the dynein pathway from fungi to mammals and is mutated in people with the neurodevelopmental disease lissencephaly. Lis1 is required for active dynein complexes to form, but how it enables this is unclear. Here, we present a structure of two yeast 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 Lis1's regulation of dynein in Saccharomyces cerevisiae in vivo and the formation of active human dynein-dynactin-activating adapter complexes in vitro. We propose that this structure represents an intermediate in dynein's activation pathway, revealing how Lis1 relieves dynein's autoinhibited state.
Topics: Animals; Humans; Cytoplasmic Dyneins; Dyneins; Classical Lissencephalies and Subcortical Band Heterotopias; Biological Transport; Cytoskeleton; Dynactin Complex; Oligonucleotides; Mammals
PubMed: 37620585
DOI: 10.1038/s41594-023-01069-6 -
Nature Communications Nov 2023Cytoplasmic dynein drives the motility and force generation functions towards the microtubule minus end. The assembly of dynein with dynactin and a cargo adaptor in an...
Cytoplasmic dynein drives the motility and force generation functions towards the microtubule minus end. The assembly of dynein with dynactin and a cargo adaptor in an active transport complex is facilitated by Lis1 and Nde1/Ndel1. Recent studies proposed that Lis1 relieves dynein from its autoinhibited conformation, but the physiological function of Nde1/Ndel1 remains elusive. Here, we investigate how human Nde1 and Lis1 regulate the assembly and subsequent motility of mammalian dynein using in vitro reconstitution and single molecule imaging. We find that Nde1 recruits Lis1 to autoinhibited dynein and promotes Lis1-mediated assembly of dynein-dynactin adaptor complexes. Nde1 can compete with the α2 subunit of platelet activator factor acetylhydrolase 1B (PAF-AH1B) for the binding of Lis1, which suggests that Nde1 may disrupt PAF-AH1B recruitment of Lis1 as a noncatalytic subunit, thus promoting Lis1 binding to dynein. Before the initiation of motility, the association of dynactin with dynein triggers the dissociation of Nde1 from dynein by competing against Nde1 binding to the dynein intermediate chain. Our results provide a mechanistic explanation for how Nde1 and Lis1 synergistically activate the dynein transport machinery.
Topics: Animals; Humans; Dyneins; Microtubule-Associated Proteins; Dynactin Complex; Microtubules; Cytoskeleton; 1-Alkyl-2-acetylglycerophosphocholine Esterase; Mammals
PubMed: 37940657
DOI: 10.1038/s41467-023-42907-x -
The EMBO Journal Dec 2023The microtubule motor dynein mediates polarised trafficking of a wide variety of organelles, vesicles and macromolecules. These functions are dependent on the dynactin...
The microtubule motor dynein mediates polarised trafficking of a wide variety of organelles, vesicles and macromolecules. These functions are dependent on the dynactin complex, which helps recruit cargoes to dynein's tail and activates motor movement. How the dynein-dynactin complex orchestrates trafficking of diverse cargoes is unclear. Here, we identify HEATR5B, an interactor of the adaptor protein-1 (AP1) clathrin adaptor complex, as a novel player in dynein-dynactin function. HEATR5B was recovered in a biochemical screen for proteins whose association with the dynein tail is augmented by dynactin. We show that HEATR5B binds directly to the dynein tail and dynactin and stimulates motility of AP1-associated endosomal membranes in human cells. We also demonstrate that the Drosophila HEATR5B homologue is an essential gene that selectively promotes dynein-based transport of AP1-bound membranes to the Golgi apparatus. As HEATR5B lacks the coiled-coil architecture typical of dynein adaptors, our data point to a non-canonical process orchestrating motor function on a specific cargo. We additionally show that HEATR5B promotes association of AP1 with endosomal membranes independently of dynein. Thus, HEATR5B co-ordinates multiple events in AP1-based trafficking.
Topics: Humans; Dyneins; Dynactin Complex; Microtubule-Associated Proteins; Biological Transport; Microtubules; Endosomes
PubMed: 37872872
DOI: 10.15252/embj.2023114473 -
Nature Communications Oct 2023YTHDF2 has been extensively studied and typified as an RNA-binding protein that specifically recognizes and destabilizes RNAs harboring N-methyladenosine (mA), the most...
YTHDF2 has been extensively studied and typified as an RNA-binding protein that specifically recognizes and destabilizes RNAs harboring N-methyladenosine (mA), the most prevalent internal modification found in eukaryotic RNAs. In this study, we unravel the mA-independent role of YTHDF2 in the formation of an aggresome, where cytoplasmic protein aggregates are selectively sequestered upon failure of protein homeostasis mediated by the ubiquitin-proteasome system. Downregulation of YTHDF2 in HeLa cells reduces the circularity of aggresomes and the rate of movement of misfolded polypeptides, inhibits aggresome formation, and thereby promotes cellular apoptosis. Mechanistically, YTHDF2 is recruited to a misfolded polypeptide-associated complex composed of UPF1, CTIF, eEF1A1, and DCTN1 through its interaction with UPF1. Subsequently, YTHDF2 increases the interaction between the dynein motor protein and the misfolded polypeptide-associated complex, facilitating the diffusion dynamics of the movement of misfolded polypeptides toward aggresomes. Therefore, our data reveal that YTHDF2 is a cellular factor involved in protein quality control.
Topics: Humans; Cytoplasm; Dyneins; HeLa Cells; Peptides; Protein Folding; RNA Helicases; RNA-Binding Proteins; Trans-Activators; Transcription Factors; Proteolysis; Organelles
PubMed: 37803021
DOI: 10.1038/s41467-023-42015-w -
Science (New York, N.Y.) Mar 2024Cytoplasmic dynein is a microtubule motor vital for cellular organization and division. It functions as a ~4-megadalton complex containing its cofactor dynactin and a...
Cytoplasmic dynein is a microtubule motor vital for cellular organization and division. It functions as a ~4-megadalton complex containing its cofactor dynactin and a cargo-specific coiled-coil adaptor. However, how dynein and dynactin recognize diverse adaptors, how they interact with each other during complex formation, and the role of critical regulators such as lissencephaly-1 (LIS1) protein (LIS1) remain unclear. In this study, we determined the cryo-electron microscopy structure of dynein-dynactin on microtubules with LIS1 and the lysosomal adaptor JIP3. This structure reveals the molecular basis of interactions occurring during dynein activation. We show how JIP3 activates dynein despite its atypical architecture. Unexpectedly, LIS1 binds dynactin's p150 subunit, tethering it along the length of dynein. Our data suggest that LIS1 and p150 constrain dynein-dynactin to ensure efficient complex formation.
Topics: Cryoelectron Microscopy; Dynactin Complex; Dyneins; Microtubule-Associated Proteins; Microtubules; Protein Binding; Humans; HeLa Cells; 1-Alkyl-2-acetylglycerophosphocholine Esterase; Nerve Tissue Proteins; Adaptor Proteins, Signal Transducing; WD40 Repeats; Protein Interaction Mapping
PubMed: 38547289
DOI: 10.1126/science.adk8544 -
Frontiers of Medicine Oct 2023Primary ciliary dyskinesia (PCD) is a congenital, motile ciliopathy with pleiotropic symptoms. Although nearly 50 causative genes have been identified, they only account...
Primary ciliary dyskinesia (PCD) is a congenital, motile ciliopathy with pleiotropic symptoms. Although nearly 50 causative genes have been identified, they only account for approximately 70% of definitive PCD cases. Dynein axonemal heavy chain 10 (DNAH10) encodes a subunit of the inner arm dynein heavy chain in motile cilia and sperm flagella. Based on the common axoneme structure of motile cilia and sperm flagella, DNAH10 variants are likely to cause PCD. Using exome sequencing, we identified a novel DNAH10 homozygous variant (c.589C > T, p.R197W) in a patient with PCD from a consanguineous family. The patient manifested sinusitis, bronchiectasis, situs inversus, and asthenoteratozoospermia. Immunostaining analysis showed the absence of DNAH10 and DNALI1 in the respiratory cilia, and transmission electron microscopy revealed strikingly disordered axoneme 9+2 architecture and inner dynein arm defects in the respiratory cilia and sperm flagella. Subsequently, animal models of Dnah10-knockin mice harboring missense variants and Dnah10-knockout mice recapitulated the phenotypes of PCD, including chronic respiratory infection, male infertility, and hydrocephalus. To the best of our knowledge, this study is the first to report DNAH10 deficiency related to PCD in human and mouse models, which suggests that DNAH10 recessive mutation is causative of PCD.
Topics: Humans; Male; Animals; Mice; Semen; Dyneins; Cilia; Mutation; Ciliary Motility Disorders
PubMed: 37314648
DOI: 10.1007/s11684-023-0988-8