Phospho-KNL-1 recognition by a TPR domain targets the BUB-1-BUB-3 complex to C. elegans kinetochores.

During mitosis, the Bub1-Bub3 complex concentrates at kinetochores, the microtubule-coupling interfaces on chromosomes, where it contributes to spindle checkpoint activation, kinetochore-spindle microtubule interactions, and protection of centromeric cohesion. Bub1 has a conserved N-terminal tetratricopeptide repeat (TPR) domain followed by a binding motif for its conserved interactor Bub3. The current model for Bub1-Bub3 localization to kinetochores is that Bub3, along with its bound motif from Bub1, recognizes phosphorylated "MELT" motifs in the kinetochore scaffold protein Knl1. Motivated by the greater phenotypic severity of BUB-1 versus BUB-3 loss in C. elegans, we show that the BUB-1 TPR domain directly recognizes a distinct class of phosphorylated motifs in KNL-1 and that this interaction is essential for BUB-1-BUB-3 localization and function. BUB-3 recognition of phospho-MELT motifs additively contributes to drive super-stoichiometric accumulation of BUB-1-BUB-3 on its KNL-1 scaffold during mitotic entry. Bub1's TPR domain interacts with Knl1 in other species, suggesting that collaboration of TPR-dependent and Bub3-dependent interfaces in Bub1-Bub3 localization and functions may be conserved.

Developmental dyslexia susceptibility genes DNAAF4, DCDC2, and NRSN1 are associated with brain function in fluently reading adolescents and young adults.

Reading skills and developmental dyslexia, characterized by difficulties in developing reading skills, have been associated with brain anomalies within the language network. Genetic factors contribute to developmental dyslexia risk, but the mechanisms by which these genes influence reading skills remain unclear. In this preregistered study (https://osf.io/7sehx), we explored if developmental dyslexia susceptibility genes DNAAF4, DCDC2, NRSN1, and KIAA0319 are associated with brain function in fluently reading adolescents and young adults. Functional MRI and task performance data were collected during tasks involving written and spoken sentence processing, and DNA sequence variants of developmental dyslexia susceptibility genes previously associated with brain structure anomalies were genotyped. The results revealed that variation in DNAAF4, DCDC2, and NRSN1 is associated with brain activity in key language regions: the left inferior frontal gyrus, middle temporal gyrus, and intraparietal sulcus. Furthermore, NRSN1 was associated with task performance, but KIAA0319 did not yield any significant associations. Our findings suggest that individuals with a genetic predisposition to developmental dyslexia may partly employ compensatory neural and behavioral mechanisms to maintain typical task performance. Our study highlights the relevance of these developmental dyslexia susceptibility genes in language-related brain function, even in individuals without developmental dyslexia, providing valuable insights into the genetic factors influencing language processing.

Infectious bronchitis virus (IBV) triggers autophagy to enhance viral replication by activating the VPS34 complex.

Autophagy plays an important role in the lifecycle of viruses. However, there is currently a lack of systematic research on the relationship between Infectious Bronchitis Virus (IBV) and autophagy. This study aims to investigate the impact of IBV on autophagy and the role of autophagy in viral replication. We observed that IBV infection increased the expression of microtubule-associated protein 1 light chain 3, a marker of autophagy, decreased the expression of sequestosome 1, and led to elevated intracellular LC3 puncta levels. These findings suggest that IBV infection activates the autophagic process in cells. To investigate the impact of autophagy on the replication of IBV, we utilized rapamycin as an autophagy activator and 3-methyladenine as an autophagy inhibitor. Our results indicate that IBV promotes viral replication by inducing autophagy. Further investigation revealed that IBV induces autophagosome formation by inhibiting the mTOR-ULK1 pathway and activating the activity of vacuolar protein sorting 34 (VPS34), autophagy-related gene 14, and the Beclin-1 complex. VPS34 plays a crucial role in this process, as inhibiting VPS34 protein activity enhances cell proliferation after IBV infection. Additionally, inhibiting VPS34 significantly improves the survival rate of IBV-infected chicks, suppresses IBV replication in the kidney, and alleviates tracheal, lung, and kidney damage caused by IBV infection. In summary, IBV infection can induce autophagy by modulating the mTOR/ULK1 signaling pathway and activating the VPS34 complex, while autophagy serves to promote virus replication.

Nuclear MAST4 Suppresses FOXO3 through Interaction with AKT3 and Induces Chemoresistance in Pancreatic Ductal Carcinoma.

Pancreatic ductal adenocarcinoma (PDAC) is highly malignant, with a 5-year survival rate of less than 10%. Furthermore, the acquisition of anticancer drug resistance makes PDAC treatment difficult. We established MIA-GEM cells, a PDAC cell line resistant to gemcitabine (GEM), a first-line anticancer drug, using the human PDAC cell line-MIA-PaCa-2. Microtubule-associated serine/threonine kinase-4 (MAST4) expression was increased in MIA-GEM cells compared with the parent cell line. Through inhibitor screening, dysregulated AKT signaling was identified in MIA-GEM cells with overexpression of AKT3. MAST4 knockdown effectively suppressed AKT3 overexpression, and both MAST4 and AKT3 translocation into the nucleus, phosphorylating forkhead box O3a (FOXO3) in MIA-GEM cells. Modulating FOXO3 target gene expression in these cells inhibited apoptosis while promoting stemness and proliferation. Notably, nuclear MAST4 demonstrated higher expression in GEM-resistant PDAC cases compared with that in the GEM-sensitive cases. Elevated MAST4 expression correlated with a poorer prognosis in PDAC. Consequently, nuclear MAST4 emerges as a potential marker for GEM resistance and poor prognosis, representing a novel therapeutic target for PDAC.

ATG7(2) Interacts With Metabolic Proteins and Regulates Central Energy Metabolism.

Macroautophagy/autophagy is an essential catabolic process that targets a wide variety of cellular components including proteins, organelles, and pathogens. ATG7, a protein involved in the autophagy process, plays a crucial role in maintaining cellular homeostasis and can contribute to the development of diseases such as cancer. ATG7 initiates autophagy by facilitating the lipidation of the ATG8 proteins in the growing autophagosome membrane. The noncanonical isoform ATG7(2) is unable to perform ATG8 lipidation; however, its cellular regulation and function are unknown. Here, we uncovered a distinct regulation and function of ATG7(2) in contrast with ATG7(1), the canonical isoform. First, affinity-purification mass spectrometry analysis revealed that ATG7(2) establishes direct protein-protein interactions (PPIs) with metabolic proteins, whereas ATG7(1) primarily interacts with autophagy machinery proteins. Furthermore, we identified that ATG7(2) mediates a decrease in metabolic activity, highlighting a novel splice-dependent function of this important autophagy protein. Then, we found a divergent expression pattern of ATG7(1) and ATG7(2) across human tissues. Conclusively, our work uncovers the divergent patterns of expression, protein interactions, and function of ATG7(2) in contrast to ATG7(1). These findings suggest a molecular switch between main catabolic processes through isoform-dependent expression of a key autophagy gene.

Reconstitution of Neuronal Motor Traffic on Septin-Associated Microtubules.

Reconstitution of intracellular transport in cell-free in vitro assays enables the understanding and dissection of the molecular mechanisms that underlie membrane traffic. Using total internal reflection fluorescence (TIRF) microscopy and microtubules, which are immobilized to a functionalized glass surface, the kinetic properties of single kinesin molecules can be imaged and analyzed in the presence or absence of microtubule-associated proteins. Here, we describe methods for the in vitro reconstitution of the motility of the neuronal kinesin motor KIF1A on microtubules associated with heteromeric septin (SEPT2/6/7) complexes. This method can be adapted for various neuronal septin complexes and kinesin motors, leading to new insights into the spatial regulation of neuronal membrane traffic by microtubule-associated septins.

ATF3/EGR1 regulates myocardial ischemia/reperfusion injury induced autophagy and inflammation in cardiomyocytes.

Myocardial ischemia/reperfusion injury (MIRI) is an irreversible adverse event during the management of coronary heart disease that lacks effective controls. The underlying mechanism of MIRI still requires further investigation. Recent studies have suggested that overexpression of ATF3 protects against MIRI by regulating inflammatory responses, ferroptosis, and autophagy. The downstream target of ATF3, EGR1, also showed cardioprotective properties against MIRI by promoting autophagy. Therefore, further investigating the effect of ATF3/EGR1 pathway on MIRI-induced inflammation and autophagy is needed. Cardiomyocyte MIRI model was established by challenging H9C2 cells with hypoxia/reoxygenation (H/R). The ATF3 overexpression-H/R cell model by transfecting ATF3 plasmid into the H9C2 cell line. The transcription levels of ATF3 and EGR1 were determined using RT-qPCR, the levels of TNF-α and IL-6 were determined using ELISA kits, the protein expression of LC3 I, LC3 II, and P62 was determined via WB, and microstructure of H9C2 cell was observed by transmission electron microscopy (TEM). Overexpression of ATF3 significantly downregulated Egr1 levels, indicating that EGR1 might be the target of ATF3. By upregulating ATF3 levels, the extracellular levels of the inflammatory cytokines TNF-α and IL-6 significantly decreased, and the protein expression of the autophagy markers LC3 I, LC3 II, and P62 significantly increased. TEM results revealed that the cell line in the H/R-ATF3 group exhibited a higher abundance of autophagosome enclosures of mitochondria. The results indicated that ATF3/EGR1 may alleviate inflammation and improve autophagy in an H/R-induced MIRI model of cardiomyocytes.

Knockdown of KIF23 alleviates the progression of asthma by inhibiting pyroptosis.

BACKGROUND: Asthma is a chronic disease affecting the lower respiratory tract, which can lead to death in severe cases. The cause of asthma is not fully known, so exploring its potential mechanism is necessary for the targeted therapy of asthma. METHOD: Asthma mouse model was established with ovalbumin (OVA). H&E staining, immunohistochemistry and ELISA were used to detect the inflammatory response in asthma. Transcriptome sequencing was performed to screen differentially expressed genes (DEGs). The role of KIF23 silencing in cell viability, proliferation and apoptosis was explored by cell counting kit-8, EdU assay and flow cytometry. Effects of KIF23 knockdown on inflammation, oxidative stress and pyroptosis were detected by ELISA and western blot. After screening KIF23-related signalling pathways, the effect of KIF23 on p53 signalling pathway was explored by western blot. RESULTS: In the asthma model, the levels of caspase-3, IgG in serum and inflammatory factors (interleukin (IL)-1ß, KC and tumour necrosis factor (TNF)-α) in serum and bronchoalveolar lavage fluid were increased. Transcriptome sequencing showed that there were 352 DEGs in the asthma model, and 7 hub genes including KIF23 were identified. Knockdown of KIF23 increased cell proliferation and inhibited apoptosis, inflammation and pyroptosis of BEAS-2B cells induced by IL-13 in vitro. In vivo experiments verified that knockdown of KIF23 inhibited oxidative stress, inflammation and pyroptosis to alleviate OVA-induced asthma mice. In addition, p53 signalling pathway was suppressed by KIF23 knockdown. CONCLUSION: Knockdown of KIF23 alleviated the progression of asthma by suppressing pyroptosis and inhibited p53 signalling pathway.

m6Am methyltransferase PCIF1 negatively regulates ciliation by inhibiting BICD2 expression.

N6, 2'-O-dimethyladenosine (m6Am) is a widespread RNA modification catalyzed by the methyltransferase PCIF1 (phosphorylated CTD interacting factor 1). Despite its prevalence, the biological functions of m6Am in RNA remain largely elusive. Here, we report a critical role of PCIF1-dependent m6Am RNA modification in ciliogenesis in RPE-1 cells. Our findings demonstrate that PCIF1 acts as a negative regulator of ciliation through its m6Am methyltransferase activity. A quantitative proteomic analysis identifies BICD2 as a downstream target of PCIF1, with PCIF1 depletion resulting in a significant increase in BICD2 levels. BICD2 depletion leads to a significant reduction in ciliation. Crucially, the ciliary phenotype in PCIF1-depleted cells is reversed upon BICD2 knockdown. Further investigations reveal that PCIF1 regulates BICD2 protein levels through its m6Am catalytic activity, which reduces the stability and translation efficiency of BICD2 mRNA. Single-base resolution LC-MS analysis identifies the m6Am site on BICD2 mRNA modified by PCIF1. These findings establish the essential involvement of PCIF1-dependent m6Am modification in ciliogenesis.

Linc00673-V3 positively regulates autophagy by promoting Smad3-mediated LC3B transcription in NSCLC.

Since its first discovery, long noncoding RNA Linc00673 has been linked to carcinogenesis and metastasis of various human cancers. Linc00673 had five transcriptional isoforms and their biological functions remained to be explored. Here we have reported that Linc00673-V3, one of the isoforms of Linc00673, promoted non-small cell lung cancer chemoresistance, and increased Linc00673-V3 expression level was associated with enhanced autophagy. Mechanistically, we discerned the existence of a stem-loop configuration engendered by the 1-100-nt and 2200-2275-nt fragments within Linc00673-V3. This structure inherently interacted with Smad3, thereby impeding its ubiquitination and subsequent degradation orchestrated by E3 ligase STUB1. The accumulation of Smad3 contributed to autophagy via up-regulation of LC3B transcription and ultimately conferred chemoresistance in NSCLC. Our results revealed a novel transcriptional regulation network between Linc00673-V3, Smad3, and LC3B, which provided an important insight into the interplay between autophagy regulation and non-canonical function of Smad3. Furthermore, the results from in vivo experiments suggested Linc00673-V3 targeted antisense oligonucleotide as a promising therapeutic strategy to overcome chemotherapy resistance in NSCLC.

Lack of CCDC146, a ubiquitous centriole and microtubule-associated protein, leads to non-syndromic male infertility in human and mouse.

From a cohort of 167 infertile patients suffering from multiple morphological abnormalities of the flagellum (MMAF), pathogenic bi-allelic mutations were identified in the CCDC146 gene. In somatic cells, CCDC146 is located at the centrosome and at multiple microtubule-related organelles during mitotic division, suggesting that it is a microtubule-associated protein (MAP). To decipher the molecular pathogenesis of infertility associated with CCDC146 mutations, a Ccdc146 knock-out (KO) mouse line was created. KO male mice were infertile, and sperm exhibited a phenotype identical to CCDC146 mutated patients. CCDC146 expression starts during late spermiogenesis. In the spermatozoon, the protein is conserved but is not localized to centrioles, unlike in somatic cells, rather it is present in the axoneme at the level of microtubule doublets. Expansion microscopy associated with the use of the detergent sarkosyl to solubilize microtubule doublets suggests that the protein may be a microtubule inner protein (MIP). At the subcellular level, the absence of CCDC146 impacted all microtubule-based organelles such as the manchette, the head-tail coupling apparatus (HTCA), and the axoneme. Through this study, a new genetic cause of infertility and a new factor in the formation and/or structure of the sperm axoneme were characterized.

G2 and S phase-expressed protein 1 is a biomarker for poor prognosis in lung adenocarcinoma.

Studying the regulatory mechanism and clinical application of G2 and S phase-expressed protein 1 (GTSE1) genes in lung adenocarcinoma (LUAD). LUAD data was obtained from The Cancer Genome Atlas (TCGA) database, and differentially expressed genes (DEGs) were derived by analyzing expression data using R software. Survival analysis was performed to identify genes associated with LUAD, and among them, a target gene for LUAD was identified. Further analysis of the gene expression profiling interactive analysis database revealed differences in gene expression between normal and tumor tissues of LUAD patients. Disease free survival (DFS) and overall survival (OS) of the GTSE1 genes in LUAD were compared. The study conducted a GSEA analysis of GTSE1 expression and further investigated the relationships between GTSE1 expression and the survival time of LUAD patients at different pathological stages. The correlations between OS and GTSE1 gene expression were explored based on different treatments. Additionally, the correlation between the GTSE1 gene and immune infiltration was analyzed. The results indicated that the expression of GTSE1 was significantly higher in tumor tissues of LUAD compared to normal tissues. Furthermore, patients with high GTSE1 expression had significantly lower survival rates for OS and DFS compared to patients with low expression of GTSE1. The GSEA analysis of GTSE1 revealed its involvement in LUAD through the Reactome unwinding of DNA and Biocarta ranms pathway. In patients with LUAD at the pathological T2 stage, low expression of GTSE1 was associated with longer survival time. Furthermore, LUAD patients with low GTSE1 expression who underwent surgery without chemotherapy exhibited a longer survival time. The GTST1 gene, identified as a target gene of LUAD, was validated through cell experiments and pathological sections. GTSE1 can be used as a marker and therapeutic target for LUAD. The survival of LUAD patients can be improved by reducing the expression of GTSE1.

Impaired autophagic flux in the human brain after traumatic brain injury.

Emerging evidence indicates that dysfunctional autophagic flux significantly contributes to the pathology of experimental traumatic brain injury (TBI). The current study aims to clarify its role post-TBI using brain tissues from TBI patients. Histological examinations, including hematoxylin and eosin, Nissl staining, and brain water content analysis, were employed to monitor brain damage progression. Electron microscopy was used to visualize autophagic vesicles. Western blotting and immunohistochemistry were performed to analyze the levels of important autophagic flux-related proteins such as Beclin1, autophagy-related protein 5, lipidated microtubule-associated protein light-chain 3 (LC3-II), autophagic substrate sequestosome 1 (SQSTM1/p62), and cathepsin D (CTSD), a lysosomal enzyme. Immunofluorescence assays evaluated LC3 colocalization with NeuN, P62, or CTSD, and correlation analysis linked autophagy-related protein levels with brain water content and Nissl bodies. Early-stage TBI results showed increased autophagic vesicles and LC3-positive neurons, suggesting autophagosome accumulation due to enhanced initiation and reduced clearance. As TBI progressed, LC3-II and P62 levels increased, while CTSD levels decreased. This indicates autophagosome overload from impaired degradation rather than increased initiation. The study reveals a potential association between worsening brain damage and impaired autophagic flux post-TBI, positioning improved autophagic flux as a viable therapeutic target for TBI.

Molecular mechanism of dynein-dynactin complex assembly by LIS1.

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.

AurkA/TPX2 co-overexpression in nontransformed cells promotes genome instability through induction of chromosome mis-segregation and attenuation of the p53 signalling pathway.

The Aurora-A kinase (AurkA) and its major regulator TPX2 (Targeting Protein for Xklp2) are key mitotic players frequently co-overexpressed in human cancers, and the link between deregulation of the AurkA/TPX2 complex and tumourigenesis is actively investigated. Chromosomal instability, one of the hallmarks of cancer related to the development of intra-tumour heterogeneity, metastasis and chemo-resistance, has been frequently associated with TPX2-overexpressing tumours. In this study we aimed to investigate the actual contribution to chromosomal instability of deregulating the AurkA/TPX2 complex, by overexpressing it in nontransformed hTERT RPE-1 cells. Our results show that overexpression of both AurkA and TPX2 results in increased AurkA activation and severe mitotic defects, compared to AurkA overexpression alone. We also show that AurkA/TPX2 co-overexpression yields increased aneuploidy in daughter cells and the generation of micronucleated cells. Interestingly, the p53/p21 axis response is impaired in AurkA/TPX2 overexpressing cells subjected to different stimuli; consistently, cells acquire increased ability to proliferate after independent induction of mitotic errors, i.e. following nocodazole treatment. Based on our observation that increased levels of the AurkA/TPX2 complex affect chromosome segregation fidelity and interfere with the activation of a pivotal surveillance mechanism in response to altered cell division, we propose that co-overexpression of AurkA and TPX2 per se represents a condition promoting the generation of a genetically unstable context in nontransformed human cells.

Sex-specific genetic architecture of blood pressure.

The genetic and genomic basis of sex differences in blood pressure (BP) traits remain unstudied at scale. Here, we conducted sex-stratified and combined-sex genome-wide association studies of BP traits using the UK Biobank resource, identifying 1,346 previously reported and 29 new BP trait-associated loci. Among associated loci, 412 were female-specific (Pfemale ≤ 5 × 10-8; Pmale > 5 × 10-8) and 142 were male-specific (Pmale ≤ 5 × 10-8; Pfemale > 5 × 10-8); these sex-specific loci were enriched for hormone-related transcription factors, in particular, estrogen receptor 1. Analyses of gene-by-sex interactions and sexually dimorphic effects identified four genomic regions, showing female-specific associations with diastolic BP or pulse pressure, including the chromosome 13q34-COL4A1/COL4A2 locus. Notably, female-specific pulse pressure-associated loci exhibited enriched acetylated histone H3 Lys27 modifications in arterial tissues and a female-specific association with fibromuscular dysplasia, a female-biased vascular disease; colocalization signals included Chr13q34: COL4A1/COL4A2, Chr9p21: CDKN2B-AS1 and Chr4q32.1: MAP9 regions. Sex-specific and sex-biased polygenic associations of BP traits were associated with multiple cardiovascular traits. These findings suggest potentially clinically significant and BP sex-specific pleiotropic effects on cardiovascular diseases.

Neuronal ageing is promoted by the decay of the microtubule cytoskeleton.

Natural ageing is accompanied by a decline in motor, sensory, and cognitive functions, all impacting quality of life. Ageing is also the predominant risk factor for many neurodegenerative diseases, including Parkinson's disease and Alzheimer's disease. We need to therefore gain a better understanding of the cellular and physiological processes underlying age-related neuronal decay. However, gaining this understanding is a slow process due to the large amount of time required to age mammalian or vertebrate animal models. Here, we introduce a new cellular model within the Drosophila brain, in which we report classical ageing hallmarks previously observed in the primate brain. These hallmarks include axonal swellings, cytoskeletal decay, a reduction in axonal calibre, and morphological changes arising at synaptic terminals. In the fly brain, these changes begin to occur within a few weeks, ideal to study the underlying mechanisms of ageing. We discovered that the decay of the neuronal microtubule (MT) cytoskeleton precedes the onset of other ageing hallmarks. We showed that the MT-binding factors Tau, EB1, and Shot/MACF1, are necessary for MT maintenance in axons and synapses, and that their functional loss during ageing triggers MT bundle decay, followed by a decline in axons and synaptic terminals. Furthermore, genetic manipulations that improve MT networks slowed down the onset of neuronal ageing hallmarks and confer aged specimens the ability to outperform age-matched controls. Our work suggests that MT networks are a key lesion site in ageing neurons and therefore the MT cytoskeleton offers a promising target to improve neuronal decay in advanced age.

The FBXW7-binding sites on FAM83D are potential targets for cancer therapy.

Increasing evidence shows the oncogenic function of FAM83D in human cancer, but how FAM83D exerts its oncogenic function remains largely unclear. Here, we investigated the importance of FAM83D/FBXW7 interaction in breast cancer (BC). We systematically mapped the FBXW7-binding sites on FAM83D through a comprehensive mutational analysis together with co-immunoprecipitation assay. Mutations at the FBXW7-binding sites on FAM83D led to that FAM83D lost its capability to promote the ubiquitination and proteasomal degradation of FBXW7; cell proliferation, migration, and invasion in vitro; and tumor growth and metastasis in vivo, indicating that the FBXW7-binding sites on FAM83D are essential for its oncogenic functions. A meta-evaluation of FAM83D revealed that the prognostic impact of FAM83D was independent on molecular subtypes. The higher expression of FAM83D has poorer prognosis. Moreover, high expression of FAM83D confers resistance to chemotherapy in BCs, which is experimentally validated in vitro. We conclude that identification of FBXW7-binding sites on FAM83D not only reveals the importance for FAM83D oncogenic function, but also provides valuable insights for drug target.

A stable microtubule bundle formed through an orchestrated multistep process controls quiescence exit.

Cells fine-tune microtubule assembly in both space and time to give rise to distinct edifices with specific cellular functions. In proliferating cells, microtubules are highly dynamics, and proliferation cessation often leads to their stabilization. One of the most stable microtubule structures identified to date is the nuclear bundle assembled in quiescent yeast. In this article, we characterize the original multistep process driving the assembly of this structure. This Aurora B-dependent mechanism follows a precise temporality that relies on the sequential actions of kinesin-14, kinesin-5, and involves both microtubule-kinetochore and kinetochore-kinetochore interactions. Upon quiescence exit, the microtubule bundle is disassembled via a cooperative process involving kinesin-8 and its full disassembly is required prior to cells re-entry into proliferation. Overall, our study provides the first description, at the molecular scale, of the entire life cycle of a stable microtubule structure in vivo and sheds light on its physiological function.

Cellular senescence gene TACC3 associated with colorectal cancer risk via genetic and DNA methylated alteration.

Cell senescence genes play a vital role in the pathogenesis of colorectal cancer, a process that may involve the triggering of genetic variations and reversible phenotypes caused by epigenetic modifications. However, the specific regulatory mechanisms remain unclear. Using CellAge and The Cancer Genome Atlas databases and in-house RNA-seq data, DNA methylation-modified cellular senescence genes (DMCSGs) were validated by Support Vector Machine and correlation analyses. In 1150 cases and 1342 controls, we identified colorectal cancer risk variants in DMCSGs. The regulatory effects of gene, variant, and DNA methylation were explored through dual-luciferase and 5-azacytidine treatment experiments, complemented by multiple database analyses. Biological functions of key gene were evaluated via cell proliferation assays, SA-ß-gal staining, senescence marker detection, and immune infiltration analyses. The genetic variant rs4558926 in the downstream of TACC3 was significantly associated with colorectal cancer risk (OR = 1.35, P = 3.22 × 10-4). TACC3 mRNA expression increased due to rs4558926 C > G and decreased DNA methylation levels. The CpG sites in the TACC3 promoter region were regulated by rs4558926. TACC3 knockdown decreased proliferation and senescence in colorectal cancer cells. In addition, subjects with high-TACC3 expression presented an immunosuppressive microenvironment. These findings provide insights into the involvement of genetic variants of cellular senescence genes in the development and progression of colorectal cancer.