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PLoS Biology Oct 2023The endoplasmic reticulum (ER) forms contacts with the lysosomal compartment, regulating lysosome positioning and motility. The movements of lysosomes are controlled by...
The endoplasmic reticulum (ER) forms contacts with the lysosomal compartment, regulating lysosome positioning and motility. The movements of lysosomes are controlled by the attachment of molecular motors to their surface. However, the molecular mechanisms by which ER controls lysosome dynamics are still elusive. Here, using mouse brain extracts and mouse embryonic fibroblasts, we demonstrate that spatacsin is an ER-resident protein regulating the formation of tubular lysosomes, which are highly dynamic. Screening for spatacsin partners required for tubular lysosome formation showed spatacsin to act by regulating protein degradation. We demonstrate that spatacsin promotes the degradation of its partner AP5Z1, which regulates the relative amount of spastizin and AP5Z1 at lysosomes. Spastizin and AP5Z1 contribute to regulate tubular lysosome formation, as well as their trafficking by interacting with anterograde and retrograde motor proteins, kinesin KIF13A and dynein/dynactin subunit p150Glued, respectively. Ultimately, investigations in polarized mouse cortical neurons in culture demonstrated that spatacsin-regulated degradation of AP5Z1 controls the directionality of lysosomes trafficking. Collectively, our results identify spatacsin as a protein regulating the directionality of lysosome trafficking.
Topics: Animals; Mice; Dyneins; Fibroblasts; Lysosomes; Neurons; Proteins; Adaptor Proteins, Vesicular Transport
PubMed: 37871017
DOI: 10.1371/journal.pbio.3002337 -
Communications Biology Oct 2023How recently originated gene copies become stable genomic components remains uncertain as high sequence similarity of young duplicates precludes their functional...
How recently originated gene copies become stable genomic components remains uncertain as high sequence similarity of young duplicates precludes their functional characterization. The tandem multigene family Sdic is specific to Drosophila melanogaster and has been annotated across multiple reference-quality genome assemblies. Here we show the existence of a positive correlation between Sdic copy number and total expression, plus vast intrastrain differences in mRNA abundance among paralogs, using RNA-sequencing from testis of four strains with variable paralog composition. Single cell and nucleus RNA-sequencing data expose paralog expression differentiation in meiotic cell types within testis from third instar larva and adults. Additional RNA-sequencing across synthetic strains only differing in their Y chromosomes reveal a tissue-dependent trans-regulatory effect on Sdic: upregulation in testis and downregulation in male accessory gland. By leveraging paralog-specific expression information from tissue- and cell-specific data, our results elucidate the intraspecific functional diversification of a recently expanded tandem gene family.
Topics: Animals; Male; Drosophila melanogaster; Drosophila Proteins; Spermatogenesis; Testis; RNA; Axonemal Dyneins
PubMed: 37864070
DOI: 10.1038/s42003-023-05427-4 -
World Journal of Surgical Oncology Oct 2023Genetic variants of outer dynein arm docking complex subunit 2 (ODAD2) have been reported to be closely associated with primary ciliary dyskinesia and colorectal cancer...
Outer dynein arm docking complex subunit 2 polymorphism rs7893462 modulates hepatocellular carcinoma susceptibility and can serve as an overall survival biomarker for hepatitis B virus-related hepatocellular carcinoma after hepatectomy: a cohort study with a long-term follow-up.
BACKGROUND
Genetic variants of outer dynein arm docking complex subunit 2 (ODAD2) have been reported to be closely associated with primary ciliary dyskinesia and colorectal cancer in previous studies, but the association of genetic variants of ODAD2 with hepatocellular carcinoma (HCC) has not been reported.
METHODS
We enrolled 80 healthy subjects and 468 Guangxi hepatitis B virus (HBV)-related HCC patients in this study. A case-control study method was used to explore the association of different ODAD2-rs7893462 genotypes with hepatocarcinogenesis. A comprehensive survival analysis was used to explore the association of rs7893462 with the prognosis of HBV-related HCC in Guangxi.
RESULTS
Through a case-control study, we observed that patients carrying the G allele of rs7893462 had a markedly increased susceptibility to hepatocarcinogenesis (odds ratio = 1.712, 95% confidence interval = 1.032-2.839, P = 0.037). We found that there were significant prognosis differences among three different genotypes of rs7893462. Nomogram analysis suggested that the contribution of rs7893462 polymorphisms to the prognosis of HBV-related HCC was second only to the BCLC stage. Stratified survival analysis suggested that the AG genotype of rs7893462 was an independent prognostic risk factor for HBV-related HCC. Joint effect survival analysis also observed that the AG genotype of rs7893462 combined with clinical parameters could significantly identify HBV-related HCC patients with different prognostic outcomes more accurately, and the AG genotype was also observed to be independent of clinical factors in HBV-related HCC survival.
CONCLUSION
The ODAD2-rs7893462 polymorphisms can be used as an independent prognostic indicator of HBV-related HCC overall survival and are significantly associated with susceptibility to hepatocarcinogenesis.
Topics: Humans; Carcinoma, Hepatocellular; Hepatitis B virus; Liver Neoplasms; Dyneins; Case-Control Studies; Cohort Studies; Hepatectomy; Follow-Up Studies; Genetic Predisposition to Disease; Polymorphism, Single Nucleotide; China; Genotype; Biomarkers; Hepatitis B
PubMed: 37833735
DOI: 10.1186/s12957-023-03205-4 -
Methods in Molecular Biology (Clifton,... 2024Cytoskeletal motor proteins are essential molecular machines that hydrolyze ATP to generate force and motion along cytoskeletal filaments. Members of the dynein and...
Cytoskeletal motor proteins are essential molecular machines that hydrolyze ATP to generate force and motion along cytoskeletal filaments. Members of the dynein and kinesin superfamilies play critical roles in transporting biological payloads (such as proteins, organelles, and vesicles) along microtubule pathways, cause the beating of flagella and cilia, and act within the mitotic and meiotic spindles to segregate replicated chromosomes to progeny cells. Understanding the underlying mechanisms and behaviors of motor proteins is critical to provide better strategies for the treatment of motor protein-related diseases. Here, we provide detailed protocols for the recombinant expression of the Kinesin-1 motor KIF5C using a baculovirus/insect cell system and provide updated protocols for performing single-molecule studies using total internal reflection fluorescence microscopy and optical tweezers to study the motility and force generation of the purified motor.
Topics: Kinesins; Cytoskeletal Proteins; Microtubules; Spindle Apparatus; Dyneins
PubMed: 37824000
DOI: 10.1007/978-1-0716-3377-9_4 -
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 -
Development (Cambridge, England) Nov 2023Actin-related proteins (Arps) are classified according to their similarity to actin and are involved in diverse cellular processes. ACTL7B is a testis-specific Arp, and...
Actin-related proteins (Arps) are classified according to their similarity to actin and are involved in diverse cellular processes. ACTL7B is a testis-specific Arp, and is highly conserved in rodents and primates. ACTL7B is specifically expressed in round and elongating spermatids during spermiogenesis. Here, we have generated an Actl7b-null allele in mice to unravel the role of ACTL7B in sperm formation. Male mice homozygous for the Actl7b-null allele (Actl7b-/-) were infertile, whereas heterozygous males (Actl7b+/-) were fertile. Severe spermatid defects, such as detached acrosomes, disrupted membranes and flagella malformations start to appear after spermiogenesis step 9 in Actl7b-/- mice, finally resulting in spermatogenic arrest. Abnormal spermatids were degraded and levels of autophagy markers were increased. Co-immunoprecipitation with mass spectrometry experiments identified an interaction between ACTL7B and the LC8 dynein light chains DYNLL1 and DYNLL2, which are first detected in step 9 spermatids and mislocalized when ACTL7B is absent. Our data unequivocally establish that mutations in ACTL7B are directly related to male infertility, pressing for additional research in humans.
Topics: Animals; Humans; Male; Mice; Actins; Cytoplasmic Dyneins; Dyneins; Semen; Spermatids; Spermatogenesis; Spermatozoa; Testis
PubMed: 37800308
DOI: 10.1242/dev.201593 -
Molecular & Cellular Proteomics : MCP Nov 2023The fragile X messenger ribonucleoprotein 1 (FMRP) is a multifunctional RNA-binding protein implicated in human neurodevelopmental and neurodegenerative disorders. FMRP...
The fragile X messenger ribonucleoprotein 1 (FMRP) is a multifunctional RNA-binding protein implicated in human neurodevelopmental and neurodegenerative disorders. FMRP mediates the localization and activity-dependent translation of its associated mRNAs through the formation of phase-separated condensates that are trafficked by microtubule-based motors in axons. Axonal transport and localized mRNA translation are critical processes for long-term neuronal survival and are closely linked to the pathogenesis of neurological diseases. FMRP dynein-mediated axonal trafficking is still largely unexplored but likely to constitute a key process underlying FMRP spatiotemporal translational regulation. Here, we show that dynein light chain roadblock 1 (Dynlrb1), a subunit of the dynein complex, is a critical regulator of FMRP function. In sensory axons, FMRP associates with endolysosomal organelles, likely through annexin A11, and is retrogradely trafficked by the dynein complex in a Dynlrb1-dependent manner. Moreover, Dynlrb1 silencing induced FMRP granule accumulation and repressed the translation of microtubule-associated protein 1b, one of its primary mRNA targets. Our findings suggest that Dynlrb1 regulates FMRP function through the control of its transport and targeted degradation.
Topics: Humans; Dyneins; Fragile X Mental Retardation Protein; Axons; Sensory Receptor Cells; Microtubules; RNA, Messenger
PubMed: 37739344
DOI: 10.1016/j.mcpro.2023.100653 -
Neuroscience Research Dec 2023Kinesin motor proteins play crucial roles in anterograde transport of cargo vesicles in neurons, moving them along axons from the cell body towards the synaptic region.... (Review)
Review
Kinesin motor proteins play crucial roles in anterograde transport of cargo vesicles in neurons, moving them along axons from the cell body towards the synaptic region. Not only the transport force and velocity of single motor protein, but also the number of kinesin molecules involved in transporting a specific cargo, is pivotal for synapse formation. This collective transport by multiple kinesins ensures stable and efficient cargo transport in neurons. Abnormal increases or decreases in the number of engaged kinesin molecules per cargo could potentially act as biomarkers for neurodegenerative diseases such as Alzheimer's, Parkinson's, amyotrophic lateral sclerosis (ALS), spastic paraplegia, polydactyly syndrome, and virus transport disorders. We review here a model constructed using physical measurements to quantify the number of kinesin molecules associated with their cargo, which could shed light on the molecular mechanisms of neurodegenerative diseases related to axonal transport.
Topics: Humans; Kinesins; Axonal Transport; Axons; Dyneins; Amyotrophic Lateral Sclerosis
PubMed: 37734449
DOI: 10.1016/j.neures.2023.09.004 -
Nature Communications Sep 2023Processive transport by the microtubule motor cytoplasmic dynein requires the regulated assembly of a dynein-dynactin-adapter complex. Interactions between dynein and...
Processive transport by the microtubule motor cytoplasmic dynein requires the regulated assembly of a dynein-dynactin-adapter complex. Interactions between dynein and dynactin were initially ascribed to the dynein intermediate chain N-terminus and the dynactin subunit p150. However, recent cryo-EM structures have not resolved this interaction, questioning its importance. The intermediate chain also interacts with Nde1/Ndel1, which compete with p150 for binding. We reveal that the intermediate chain N-terminus is a critical evolutionarily conserved hub that interacts with dynactin and Ndel1, the latter of which recruits LIS1 to drive complex assembly. In additon to revealing that the intermediate chain N-terminus is likely bound to p150 in active transport complexes, our data support a model whereby Ndel1-LIS1 must dissociate prior to LIS1 being handed off to dynein in temporally discrete steps. Our work reveals previously unknown steps in the dynein activation pathway, and provide insight into the integrated activities of LIS1/Ndel1 and dynactin/cargo-adapters.
Topics: Dyneins; Dynactin Complex; Cytoplasmic Dyneins; Actin Cytoskeleton; Cytoskeleton
PubMed: 37730751
DOI: 10.1038/s41467-023-41466-5 -
Advanced Science (Weinheim,... Nov 2023The principal cause of death in cancer patients is metastasis, which remains an unresolved problem. Conventionally, metastatic dissemination is linked to...
The principal cause of death in cancer patients is metastasis, which remains an unresolved problem. Conventionally, metastatic dissemination is linked to actomyosin-driven cell locomotion. However, the locomotion of cancer cells often does not strictly line up with the measured actomyosin forces. Here, a complementary mechanism of metastatic locomotion powered by dynein-generated forces is identified. These forces arise within a non-stretchable microtubule network and drive persistent contact guidance of migrating cancer cells along the biomimetic collagen fibers. It is also shown that the dynein-powered locomotion becomes indispensable during invasive 3D migration within a tissue-like luminal network formed by spatially confining granular hydrogel scaffolds (GHS) made up of microscale hydrogel particles (microgels). These results indicate that the complementary motricity mediated by dynein is always necessary and, in certain instances, sufficient for disseminating metastatic breast cancer cells. These findings advance the fundamental understanding of cell locomotion mechanisms and expand the spectrum of clinical targets against metastasis.
Topics: Humans; Female; Dyneins; Breast Neoplasms; Actomyosin; Cell Movement; Hydrogels
PubMed: 37726225
DOI: 10.1002/advs.202302229