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Journal of Molecular Biology Sep 2012Cilia are organelles found on most eukaryotic cells, where they serve important functions in motility, sensory reception, and signaling. Recent advances in electron... (Review)
Review
Cilia are organelles found on most eukaryotic cells, where they serve important functions in motility, sensory reception, and signaling. Recent advances in electron tomography have facilitated a number of ultrastructural studies of ciliary components that have significantly improved our knowledge of cilium architecture. These studies have produced nanometer-resolution structures of axonemal dynein complexes, microtubule doublets and triplets, basal bodies, radial spokes, and nexin complexes. In addition to these electron tomography studies, several recently published crystal structures provide insights into the architecture and mechanism of dynein as well as the centriolar protein SAS-6, important for establishing the 9-fold symmetry of centrioles. Ciliary assembly requires intraflagellar transport (IFT), a process that moves macromolecules between the tip of the cilium and the cell body. IFT relies on a large 20-subunit protein complex that is thought to mediate the contacts between ciliary motor and cargo proteins. Structural investigations of IFT complexes are starting to emerge, including the first three-dimensional models of IFT material in situ, revealing how IFT particles organize into larger train-like arrays, and the high-resolution structure of the IFT25/27 subcomplex. In this review, we cover recent advances in the structural and mechanistic understanding of ciliary components and IFT complexes.
Topics: Animals; Cell Cycle Proteins; Cell Movement; Centrioles; Cilia; Dyneins; Flagella; Humans
PubMed: 22683354
DOI: 10.1016/j.jmb.2012.05.040 -
Journal of Cell Science Mar 2023The dynein-2 complex must be transported anterogradely within cilia to then drive retrograde trafficking of the intraflagellar transport (IFT) machinery containing IFT-A...
The dynein-2 complex must be transported anterogradely within cilia to then drive retrograde trafficking of the intraflagellar transport (IFT) machinery containing IFT-A and IFT-B complexes. Here, we screened for potential interactions between the dynein-2 and IFT-B complexes and found multiple interactions among the dynein-2 and IFT-B subunits. In particular, WDR60 (also known as DYNC2I1) and the DYNC2H1-DYNC2LI1 dimer from dynein-2, and IFT54 (also known as TRAF3IP1) and IFT57 from IFT-B contribute to the dynein-2-IFT-B interactions. WDR60 interacts with IFT54 via a conserved region N-terminal to its light chain-binding regions. Expression of the WDR60 constructs in WDR60-knockout (KO) cells revealed that N-terminal truncation mutants lacking the IFT54-binding site fail to rescue abnormal phenotypes of WDR60-KO cells, such as aberrant accumulation of the IFT machinery around the ciliary tip and on the distal side of the transition zone. However, a WDR60 construct specifically lacking just the IFT54-binding site substantially restored the ciliary defects. In line with the current docking model of dynein-2 with the anterograde IFT trains, these results indicate that extensive interactions involving multiple subunits from the dynein-2 and IFT-B complexes participate in their connection.
Topics: Cilia; Dyneins; Biological Transport; Cytoskeleton; Protein Domains; Flagella
PubMed: 36632779
DOI: 10.1242/jcs.260462 -
Journal of Cell Science Mar 2022Mutations in SPAG1, a dynein axonemal assembly factor (DNAAF) that facilitates the assembly of dynein arms in the cytoplasm before their transport into the cilium,...
Mutations in SPAG1, a dynein axonemal assembly factor (DNAAF) that facilitates the assembly of dynein arms in the cytoplasm before their transport into the cilium, result in primary ciliary dyskinesia (PCD), a genetically heterogenous disorder characterized by chronic oto-sino-pulmonary disease, infertility and laterality defects. To further elucidate the role of SPAG1 in dynein assembly, we examined its expression, interactions and ciliary defects in control and PCD human airway epithelia. Immunoprecipitations showed that SPAG1 interacts with multiple DNAAFs, dynein chains and canonical components of the R2TP complex. Protein levels of dynein heavy chains (DHCs) and interactions between DHCs and dynein intermediate chains (DICs) were reduced in SPAG1 mutants. We also identified a previously uncharacterized 60 kDa SPAG1 isoform, through examination of PCD subjects with an atypical ultrastructural defect for SPAG1 variants, that can partially compensate for the absence of full-length SPAG1 to assemble a reduced number of outer dynein arms. In summary, our data show that SPAG1 is necessary for axonemal dynein arm assembly by scaffolding R2TP-like complexes composed of several DNAAFs that facilitate the folding and/or binding of the DHCs to the DIC complex.
Topics: Antigens, Surface; Axonemal Dyneins; Axoneme; Cilia; Dyneins; GTP-Binding Proteins; Humans; Mutation; Respiratory System
PubMed: 35178554
DOI: 10.1242/jcs.259512 -
Nature Communications Mar 2023Spindle formation in male meiosis relies on the canonical centrosome system, which is distinct from acentrosomal oocyte meiosis, but its specific regulatory mechanisms...
Spindle formation in male meiosis relies on the canonical centrosome system, which is distinct from acentrosomal oocyte meiosis, but its specific regulatory mechanisms remain unknown. Herein, we report that DYNLRB2 (Dynein light chain roadblock-type-2) is a male meiosis-upregulated dynein light chain that is indispensable for spindle formation in meiosis I. In Dynlrb2 KO mouse testes, meiosis progression is arrested in metaphase I due to the formation of multipolar spindles with fragmented pericentriolar material (PCM). DYNLRB2 inhibits PCM fragmentation through two distinct pathways; suppressing premature centriole disengagement and targeting NuMA (nuclear mitotic apparatus) to spindle poles. The ubiquitously expressed mitotic counterpart, DYNLRB1, has similar roles in mitotic cells and maintains spindle bipolarity by targeting NuMA and suppressing centriole overduplication. Our work demonstrates that two distinct dynein complexes containing DYNLRB1 or DYNLRB2 are separately used in mitotic and meiotic spindle formations, respectively, and that both have NuMA as a common target.
Topics: Mice; Animals; Male; Dyneins; Spindle Apparatus; Centrosome; Meiosis; Metaphase
PubMed: 36973253
DOI: 10.1038/s41467-023-37370-7 -
The FEBS Journal Sep 2011Dynein, which is a minus-end-directed microtubule motor, is crucial to a range of cellular processes. The mass of its motor domain is about 10 times that of kinesin, the... (Review)
Review
Dynein, which is a minus-end-directed microtubule motor, is crucial to a range of cellular processes. The mass of its motor domain is about 10 times that of kinesin, the other microtubule motor. Its large size and the difficulty of expressing and purifying mutants have hampered progress in dynein research. Recently, however, electron microscopy, X-ray crystallography and single-molecule nanometry have shed light on several key unsolved questions concerning how the dynein molecule is organized, what conformational changes in the molecule accompany ATP hydrolysis, and whether two or three motor domains are coordinated in the movements of dynein. This minireview describes our current knowledge of the molecular organization and the force-generating mechanism of dynein, with emphasis on findings from electron microscopy and single-molecule nanometry.
Topics: Adenosine Triphosphate; Animals; Axonemal Dyneins; Biological Transport; Cytoplasmic Dyneins; Dyneins; Humans; Microtubules; Protein Conformation; Protein Interaction Domains and Motifs; Protein Subunits
PubMed: 21777385
DOI: 10.1111/j.1742-4658.2011.08253.x -
Andrology Nov 2022The dynein-related genes may have a role in the etiology of male infertility, particularly in cases of impaired sperm motility. (Meta-Analysis)
Meta-Analysis Review
BACKGROUND
The dynein-related genes may have a role in the etiology of male infertility, particularly in cases of impaired sperm motility.
OBJECTIVES
The goal of this review is to compile a list of the most important dynein-related candidate genes that may contribute to male factor infertility.
MATERIALS AND METHODS
Databases were searched using the keywords "dynein," "male," "infertility," and by applying strict inclusion criteria. A meta-analysis was also performed by using the eligible case-control studies. The odd ratios (ORs), the Z-test score, and the level of significance were determined using a fixed model with a p value of 0.05. Funnel plots were used to check for publication bias.
RESULTS
There were 35 studies that met the inclusion criteria. There were a total of 15 genes responsible for the production of dynein structural proteins, the production of dynein assembling factors, and potentially associated with male infertility. A total of five case-control studies were eligible for inclusion in the meta-analysis. Variants in the dynein-related genes were linked to an increased the risk of male infertility (OR = 21.52, 95% confidence interval 8.34-55.50, Z test = 6.35, p < 0.05). The percentage of heterogeneity, I , was 47.00%. The lack of variants in the dynein genes was an advantage, and this was statistically significant.
DISCUSSION
The results from the present review illustrate that pathogenic variants in genes both for dynein synthesis and for dynein assembly factors could be associated with isolated cases of male infertility without any other symptoms.
CONCLUSIONS
The genes addressed in this study, which are involved in both the production and assembly of dynein, could be used as molecular targets for future research into the etiology of sperm motility problems.
Topics: Dyneins; Humans; Infertility, Male; Male; Mutation; Sperm Motility; Spermatozoa
PubMed: 36057791
DOI: 10.1111/andr.13287 -
Cell Communication and Signaling : CCS Jun 2023LRRC6 is an assembly factor for dynein arms in the cytoplasm of motile ciliated cells, and when mutated, dynein arm components remained in the cytoplasm. Here, we...
BACKGROUND
LRRC6 is an assembly factor for dynein arms in the cytoplasm of motile ciliated cells, and when mutated, dynein arm components remained in the cytoplasm. Here, we demonstrate the role of LRRC6 in the active nuclear translocation of FOXJ1, a master regulator for cilia-associated gene transcription.
METHODS
We generated Lrrc6 knockout (KO) mice, and we investigated the role of LRRC6 on ciliopathy development by using proteomic, transcriptomic, and immunofluorescence analysis. Experiments on mouse basal cell organoids confirmed the biological relevance of our findings.
RESULTS
The absence of LRRC6 in multi-ciliated cells hinders the assembly of ODA and IDA components of cilia; in this study, we showed that the overall expression of proteins related to cilia decreased as well. Expression of cilia-related transcripts, specifically ODA and IDA components, dynein axonemal assembly factors, radial spokes, and central apparatus was lower in Lrrc6 KO mice than in wild-type mice. We demonstrated that FOXJ1 was present in the cytoplasm and translocated into the nucleus when LRRC6 was expressed and that this process was blocked by INI-43, an importin α inhibitor.
CONCLUSIONS
Taken together, these results hinted at the LRRC6 transcriptional regulation of cilia-related genes via the nuclear translocation of FOXJ1. Video Abstract.
Topics: Animals; Mice; Cilia; Dyneins; Forkhead Transcription Factors; Gene Expression Regulation; Mice, Knockout; Proteins; Proteomics; Cytoskeletal Proteins
PubMed: 37328841
DOI: 10.1186/s12964-023-01135-y -
Nature Reviews. Molecular Cell Biology Dec 2009Eukaryotic cells use cytoskeletal motor proteins to transport many different intracellular cargos. Numerous kinesins and myosins have evolved to cope with the various... (Review)
Review
Eukaryotic cells use cytoskeletal motor proteins to transport many different intracellular cargos. Numerous kinesins and myosins have evolved to cope with the various transport needs that have arisen during eukaryotic evolution. Surprisingly, a single cytoplasmic dynein (a minus end-directed microtubule motor) carries out similarly diverse transport activities as the many different types of kinesin. How is dynein coupled to its wide range of cargos and how is it spatially and temporally regulated? The answer could lie in the several multifunctional adaptors, including dynactin, lissencephaly 1, nuclear distribution protein E (NUDE) and NUDE-like, Bicaudal D, Rod-ZW10-Zwilch and Spindly, that regulate dynein function and localization.
Topics: Adaptor Proteins, Signal Transducing; Animals; Cytoplasm; Dynactin Complex; Dyneins; Humans; Microtubule-Associated Proteins
PubMed: 19935668
DOI: 10.1038/nrm2804 -
Journal of Structural Biology Aug 2012Axonemal dyneins are AAA(+) enzymes that convert ATP hydrolysis to mechanical work. This leads to the sliding of doublet microtubules with respect to each other and... (Review)
Review
Axonemal dyneins are AAA(+) enzymes that convert ATP hydrolysis to mechanical work. This leads to the sliding of doublet microtubules with respect to each other and ultimately the generation of ciliary/flagellar beating. However, in order for useful work to be generated, the action of individual dynein motors must be precisely controlled. In addition, cells modulate the motility of these organelles through a variety of second messenger systems and these signals too must be integrated by the dynein motors to yield an appropriate output. This review describes the current status of efforts to understand dynein control mechanisms and their connectivity focusing mainly on studies of the outer dynein arm from axonemes of the unicellular biflagellate green alga Chlamydomonas.
Topics: Axonemal Dyneins; Chlamydomonas; Dyneins
PubMed: 22406539
DOI: 10.1016/j.jsb.2012.02.013 -
Journal of Biomedical Science Jun 2022In Neisseria meningitidis the HrpA/HrpB two-partner secretion system (TPS) was implicated in diverse functions including meningococcal competition, biofilm formation,...
BACKGROUND
In Neisseria meningitidis the HrpA/HrpB two-partner secretion system (TPS) was implicated in diverse functions including meningococcal competition, biofilm formation, adherence to epithelial cells, intracellular survival and vacuolar escape. These diverse functions could be attributed to distinct domains of secreted HrpA.
METHODS
A yeast two-hybrid screening, in vitro pull-down assay and immunofluorescence microscopy experiments were used to investigate the interaction between HrpA and the dynein light-chain, Tctex-type 1 (DYNLT1). In silico modeling was used to analyze HrpA structure. Western blot analysis was used to investigate apoptotic and pyroptotic markers.
RESULTS
The HrpA carboxy-terminal region acts as a manganese-dependent cell lysin, while the results of a yeast two-hybrid screening demonstrated that the HrpA middle region has the ability to bind the dynein light-chain, Tctex-type 1 (DYNLT1). This interaction was confirmed by in vitro pull-down assay and immunofluorescence microscopy experiments showing co-localization of N. meningitidis with DYNLT1 in infected epithelial cells. In silico modeling revealed that the HrpA-M interface interacting with the DYNLT1 has similarity with capsid proteins of neurotropic viruses that interact with the DYNLT1. Indeed, we found that HrpA plays a key role in infection of and meningococcal trafficking within neuronal cells, and is implicated in the modulation of the balance between apoptosis and pyroptosis.
CONCLUSIONS
Our findings revealed that N. meningitidis is able to effectively infect and survive in neuronal cells, and that this ability is dependent on HrpA, which establishes a direct protein-protein interaction with DYNLTI in these cells, suggesting that the HrpA interaction with dynein could be fundamental for N. meningitidis spreading inside the neurons. Moreover, we found that the balance between apoptotic and pyroptotic pathways is heavily affected by HrpA.
Topics: Dyneins; Epithelial Cells; Neisseria meningitidis; Pyroptosis; Saccharomyces cerevisiae
PubMed: 35765029
DOI: 10.1186/s12929-022-00829-8