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Cells self-organize molecules in space and time to generate complex behaviors, but we lack synthetic strategies for engineering spatiotemporal signaling. We present a programmable reaction-diffusion platform for designing protein oscillations, patterns, and circuits in mammalian cells using two bacterial proteins, MinD and MinE (MinDE). MinDE circuits act like "single-cell radios," emitting frequency-barcoded fluorescence signals that can be spectrally isolated and analyzed using digital signal processing tools. We define how to genetically program these signals and connect their spatiotemporal dynamics to cell biology using engineerable protein-protein interactions. This enabled us to construct sensitive reporter circuits that broadcast endogenous cell signaling dynamics on a frequency-barcoded imaging channel and to build control signal circuits that synthetically pattern activities in the cell, such as protein condensate assembly and actin filamentation. Our work establishes a paradigm for visualizing, probing, and engineering cellular activities at length and timescales critical for biological function.
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Proteínas de Bactérias , Células Eucarióticas , Transdução de Sinais , Animais , Mamíferos , Biologia Sintética/métodos , Células Eucarióticas/metabolismoRESUMO
Microtubule filaments are assembled into higher-order structures using microtubule-associated proteins. However, synthetic MAPs that direct the formation of new structures are challenging to design, as nanoscale biochemical activities must be organized across micron length-scales. Here, we develop modular MAP-IDR condensates (synMAPs) that enable inducible assembly of higher-order microtubule structures for synthetic exploration in vitro and in mammalian cells. synMAPs harness a small microtubule-binding domain from oligodendrocytes (TPPP) whose activity we show can be rewired by interaction with unrelated condensate-forming IDR sequences. This combination is sufficient to allow synMAPs to self-organize multivalent structures that bind and bridge microtubules into higher-order architectures. By regulating the connection between the microtubule-binding domain and condensate-forming components of a synMAP, the formation of these structures can be triggered by small molecules or cell-signaling inputs. We systematically test a panel of synMAP circuit designs to define how the assembly of these synthetic microtubule structures can be controlled at the nanoscale (via microtubule-binding affinity) and microscale (via condensate formation). synMAPs thus provide a modular starting point for the design of higher-order microtubule systems and an experimental testbed for exploring condensate-directed mechanisms of higher-order microtubule assembly from the bottom-up.
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An increased neutrophil-to-lymphocyte ratio (NLR) is a poor prognostic biomarker in various types of cancer, because it reflects the inhibition of lymphocytes in the circulation and tumors. In urologic cancers, upper tract urothelial carcinoma (UTUC) is known for its aggressive features and lack of T cell infiltration; however, the association between neutrophils and suppressed T lymphocytes in UTUC is largely unknown. In this study, we examined the relationship between UTUC-derived factors and tumor-associated neutrophils or T lymphocytes. The culture supernatant from UTUC tumor tissue modulated neutrophils to inhibit T cell proliferation. Among the dominant factors secreted by UTUC tumor tissue, apolipoprotein A1 (Apo-A1) exhibited a positive correlation with NLR. Moreover, tumor-infiltrating neutrophils were inversely correlated with tumor-infiltrating T cells. Elevated Apo-A1 levels in UTUC were also inversely associated with the population of tumor-infiltrating T cells. Our findings indicate that elevated Apo-A1 expression in UTUC correlates with tumor-associated neutrophils and T cells. This suggests a potential immunomodulatory effect on neutrophils and T cells within the tumor microenvironment, which may represent therapeutic targets for UTUC treatment.
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Myocardial hypertrophy plays a crucial role in cardiovascular disease (CVD) development. Myocardial hypertrophy is an adaptive response by myocardial cells to stress after cardiac injury to maintain cardiac output and function. Angiotensin II (Ang-II) regulates CVD through the renin-angiotensin-aldosterone system, and its signaling in cardiac myocytes leads to excessive reactive oxygen species (ROS) production, oxidative stress, and inflammation. Sesamin (SA), a natural compound in sesame seeds, has anti-inflammatory and anti-apoptotic effects. This study investigated whether SA could attenuate hypertrophic damage and oxidative injuries in H9c2 cells under Ang-II stimulation. We found that SA decreased the cell surface area. Furthermore, Ang-II treatment reduced Ang-II-increased ANP, BNP, and ß-MHC expression. Ang-II enhanced NADPH oxidase activity, ROS formation, and decreased Superoxide Dismutase (SOD) activity. SA treatment reduces Ang-II-caused oxidative injuries. We also found that SA mitigates Ang-II-induced apoptosis and pro-inflammatory responses. In conclusion, SA could attenuate Ang-II-induced cardiac hypertrophic injuries by inhibiting oxidative stress, apoptosis, and inflammation in H9c2 cells. Therefore, SA might be a potential supplement for CVD management.
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Angiotensina II , Doenças Cardiovasculares , Humanos , Angiotensina II/toxicidade , Angiotensina II/metabolismo , Espécies Reativas de Oxigênio/metabolismo , Estresse Oxidativo , Cardiomegalia/induzido quimicamente , Miócitos Cardíacos , Doenças Cardiovasculares/metabolismoRESUMO
A one-on-one dialogue-based mathematics intelligent tutoring system (ITS) for learning multiplication and division of fractions was developed and evaluated in this study. This system could identify students' error types and misconceptions in real-time by using a block-based matching method. The adaptive dialogue-based instruction was supported by a response-driven tutoring model, which was constructed based on the diagnostic teaching methodology. Instructional strategies including provoking cognitive conflict, problem simplification and representational teaching were used in the tutoring model of the system. Effectiveness of the math ITS in remedial instruction was evaluated through a quasi-experimental study. The participants of the study were 66 sixth graders chosen from central Taiwan. They were divided into an experimental group of 35 and a control group of 31. One week after the pretest, the experimental group received 2-h one-on-one instruction via the math ITS, while the control group took a 2-h conventional teacher instruction with the same teaching content in the classroom. All participants took a post-test within 2 days after the remedial instruction. The results showed that the experimental group using the math ITS significantly outperformed the control group. Further analysis indicated that the math ITS had a significant effect on the lesser-performing group (the lower 75% in the pretest score). In addition, a usability and user experience survey showed that students were willing and likely to learn mathematics using the dialogue-based math ITS.
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Nuclear accessibility of transcription factors controls gene expression, co-regulated by Ran-dependent nuclear localization and a competitive regulatory network. Here, we reveal that nuclear import factor-facilitated transcriptional repression attenuates ribosome biogenesis under chronic salt stress. Kap114p, one of the karyopherin-ßs (Kap-ßs) that mediates nuclear import of yeast TATA-binding protein (yTBP), exhibits a yTBP-binding affinity four orders of magnitude greater than its counterparts and suppresses binding of yTBP with DNA. Our crystal structure of Kap114p reveals an extensively negatively charged concave surface, accounting for high-affinity basic-protein binding. KAP114 knockout in yeast leads to a high-salt growth defect, with transcriptomic analyses revealing that Kap114p modulates expression of genes associated with ribosomal biogenesis by suppressing yTBP binding to target promoters, a trans-repression mechanism we attribute to reduced nuclear Ran levels under salinity stress. Our findings reveal that Ran integrates the nuclear transport pathway and transcription regulatory network, allowing yeast to respond to environmental stresses.
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Carioferinas , Proteínas de Saccharomyces cerevisiae , Núcleo Celular/genética , Núcleo Celular/metabolismo , Expressão Gênica , Proteínas Nucleares/metabolismo , Ribossomos/genética , Ribossomos/metabolismo , Proteínas de Saccharomyces cerevisiae/genética , Proteínas de Saccharomyces cerevisiae/metabolismo , beta Carioferinas/genéticaRESUMO
BACKGROUND: Intensity-modulated radiotherapy (IMRT) has yet to show its capability in the adjuvant treatment of locally advanced rectal cancer. The purpose of this study is to evaluate the clinical efficacy and safety profile of IMRT in the adjuvant treatment of rectal cancer. METHOD: Consecutive patients with resected locally advanced rectal cancer who had IMRT as part of adjuvant treatment between 2008 and 2014 were identified. The medical records and dosimetric parameters of 72 patients were retrospectively examined. RESULTS: The median follow-up time was 4.36 years (range 0.16-8.49 years). Overall survival rate and disease-free survival rate at 3 year was 79% (95% CI: 66.4-7.3%) and 70% (95% CI: 56.6-79.6%), respectively. Local control rate was 95%. The median bowel bag V45 was 282 ml (249-458 ml) and bone marrow V40 was 29%. Most acute toxicities were self-limited. Concurrent use of chemotherapy was associated with greater odds of ≥Grade 2 acute neutropenia (OR 25.44, P = 0.022). CONCLUSION: Integration of IMRT in the adjuvant treatment of rectal cancer is promising with competitive local control rate. Acute toxicities are mostly self-limited.
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Radioterapia de Intensidade Modulada/efeitos adversos , Neoplasias Retais/radioterapia , Idoso , Intervalo Livre de Doença , Feminino , Humanos , Estimativa de Kaplan-Meier , Masculino , Pessoa de Meia-Idade , Recidiva Local de Neoplasia/patologia , Radioterapia Adjuvante , Estudos Retrospectivos , Taxa de Sobrevida , Resultado do TratamentoRESUMO
The assembly of Ga alloys with Ni or Ni alloy has been widely developed for various low-temperature applications in recent years. In the constituent Ni-Ga binary system, however, the phase equilibrium with the phase "NiGa5" and its stability has scarcely been investigated. The present study used the diffusion couple technique combined with SEM-EPMA and XRD analysis to examine the phase stability and the homogeneity range of the phase. The results show that "NiGa5" is a stable phase in the binary system with little homogeneity range and suggest that the peritectic reaction L+Ni3Ga7âNiGa5 lies between 112.0 and 115.5 °C. This work provides new information for the modification of the Ga-rich low-T region of the Ni-Ga phase diagram.
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BACKGROUND: Early palliative care (EPC) benefits some cancers, but its clinical outcomes differ depending on patients' racial and ethnic disparities, and customs. To determine whether EPC improves symptoms, emotional distress, and quality of life among Taiwanese patients with early or advanced-stage head and neck cancer (HNC). METHODS: Based on participants' pathological stages, they were categorized as having early and advanced-stage HNC. Those willing and unwilling to undergo EPC were assigned to the EPC and standard groups, respectively. Their daily cancer-related symptoms were assessed using the Distress Thermometer (DT) and MD Anderson Symptom Inventory (MDASI), whose scores' concurrent validity was evaluated using the European Organization for Research and Treatment of Core Quality of Life (EORTC-QLQ-C30) and Head and Neck 35 (EORTC-QLQ-H&N35) questionnaires. RESULTS: Patients (n = 93) diagnosed with HNC at Taiwan's Chia-Yi Christian Hospital from November 2020 to October 2022 were recruited. The patients voluntarily split into two groups: EPC groups and standard groups (23 and 11 in early-stage; 46 and 13 in advanced-stage, respectively). DT assessment showed significant emotional distress improvements for all patients with HNC who received EPC. The EORTC-QLQ-C30 questionnaire indicated that, compared to standard interventions, EPC groups significantly improved the quality of life and some symptoms for both early and advanced-stage HNC patients. However, the EORTC-QLQ-H&N35 questionnaire found no significant difference between the two groups. Furthermore, advanced-stage patients' anticancer treatment completion rates with EPC and standard interventions were 95.35% and 75%, respectively. CONCLUSION: EPC improves symptoms, emotional distress, quality of life, and treatment completion rates in Taiwanese patients with early or advanced-stage HNC. Nonetheless, further extensive clinical studies are required for validation.
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Neoplasias de Cabeça e Pescoço , Cuidados Paliativos , Qualidade de Vida , Humanos , Neoplasias de Cabeça e Pescoço/terapia , Neoplasias de Cabeça e Pescoço/psicologia , Masculino , Feminino , Pessoa de Meia-Idade , Idoso , Taiwan , Adulto , Inquéritos e QuestionáriosRESUMO
Microtubules filaments are assembled into higher-order structures and machines critical for cellular processes using microtubule-associated proteins (MAPs). However, the design of synthetic MAPs that direct the formation of new structures in cells is challenging, as nanoscale biochemical activities must be organized across micron length-scales. Here we develop synthetic MAP-IDR condensates (synMAPs) that provide tunable and regulatable assembly of higher-order microtubule structures in vitro and in mammalian cells. synMAPs harness a small microtubule-binding domain from oligodendrocytes (TPPP) whose activity can be synthetically rewired by interaction with condensate-forming IDR sequences. This combination allows synMAPs to self-organize multivalent structures that bind and bridge microtubules into synthetic architectures. Regulating the connection between the microtubule-binding and condensate-forming components allows synMAPs to act as nodes in more complex cytoskeletal circuits in which the formation and dynamics of the microtubule structure can be controlled by small molecules or cell-signaling inputs. By systematically testing a panel of synMAP circuit designs, we define a two-level control scheme for dynamic assembly of microtubule architectures at the nanoscale (via microtubule-binding) and microscale (via condensate formation). synMAPs provide a compact and rationally engineerable starting point for the design of more complex microtubule architectures and cellular machines.
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Hypertrophic cardiomyopathy accompanies numerous cardiovascular diseases, and the intervention of cardiac hypertrophy is an important issue to prevent detrimental consequences. Mangiferin (MGN) is a glucosylxanthone found in Mangifera indica, which exhibits anti-oxidant and anti-inflammatory properties. Various studies have demonstrated the cardioprotective potential of MGN, but the mechanisms behind its beneficial effects have not been fully revealed. Here, angiotensin-II (Ang-II) was used to induce cardiac hypertrophy, and we examined cell size, expression of hypertrophy markers (e.g., ANP, BNP, and [Formula: see text]-MHC), and oxidative stress (e.g., the ratio of NADPH/NADP[Formula: see text], the expression of p22phox and p67phox, and ROS and SOD production) of cardiomyocytes. Moreover, we assessed the activation of mitogen-activated protein kinase (MAPK) signaling (e.g., p38 and ERK) and the NF-[Formula: see text]Bp65/iNOS axis. Additionally, an annexin V/PI assay was employed to evaluate whether MGN administration can attenuate Ang-II-elicited apoptosis. Lastly, the expression of Ang-II type 1 receptor (AT1) was measured to confirm its involvement in MGN-mediated protection. Our results showed that treatment with MGN attenuated the Ang-II-induced cell size, expression of hypertrophy markers, and oxidative stress in cardiomyocytes. MGN also abrogated the activation of MAPK signaling and the NF-[Formula: see text]Bp65/iNOS axis. Additionally, MGN prevented apoptosis and downregulated the elevation of AT1 in cardiomyocytes that had been exposed to Ang-II. Altogether, these results demonstrated the potential of using MGN to ameliorate the Ang-II-associated cardiac hypertrophy, which may be due to its anti-oxidant and anti-inflammatory effects through suppression of MAPK signaling and the NF-[Formula: see text]Bp65/iNOS axis.
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Whole-brain radiotherapy (WBRT) can alleviate symptoms in patients with brain metastases. However, WBRT may damage the hippocampus. Volumetric modulated arc therapy (VMAT) can achieve a suitable coverage of the target region and a more conforming dose distribution whereas decreasing the dose to organs-at-risk (OARs). Herein, we aimed to compare the differences between treatment plans utilizing coplanar VMAT and noncoplanar VMAT in hippocampal-sparing WBRT (HS-WBRT). Ten patients were included in this study. For each patient, the Eclipse A10 treatment planning system was used to generate 1 coplanar VMAT (C-VMAT) and 2 noncoplanar VMAT treatment plans with various beam angles (noncoplanar VMAT A [NC-A] and noncoplanar VMAT B [NC-B]) for HS-WBRT. The prescribed dose was 30 Gy in 12 fractions. Treatment plans were established based on the OAR dose constraints of the Radiation Therapy Oncology Group 0933 (RTOG 0933). Parameters such as the global maximum dose, dose conformity, dose homogeneity of plans, and OAR doses were evaluated. The maximum biologically equivalent doses in 2-Gy fractions (EQD2) of OARs in C-VMAT were 9.17 ± 0.61, 42.79 ± 2.00, and 42.84 ± 3.52 Gy in the hippocampus, brain stem, and optic chiasm, respectively, which were the lowest among the 3 treatment plans. There was no significant difference in dose conformity among the 3 treatment plans. However, NC-A had a slightly better conformity than C-VMAT and NC-B. NC-A had the best homogeneity, and NC-B had the worst homogeneity (pâ¯=â¯0.042). NC-A and NC-B had the lowest and highest global dose maximum, respectively. Therefore, NC-A, which had an intermediate performance in terms of OAR doses, had the best quality parameters. We used the quality score table based on the p-value to evaluate the significant difference between each treatment technique from the multiparameter results. In terms of treatment plan parameters, only NC-A received a score of 2; for OAR doses, C-VMAT, NC-A, and NC-B received a score of 6, 3, and 5, respectively. For the overall evaluation, C-VMAT, NC-A, and NC-B received a total score of 6, 5, and 5, respectively. Rather than noncoplanar VMAT, 3 full-arc C-VMATs should be utilized in HS-WBRT. C-VMAT can simultaneously maintain treatment plan quality and decrease patient alignment time and total treatment time.
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BACKGROUND: This study aimed to ascertain if the incorporation of intensity-modulated radiotherapy (IMRT) with chemotherapy (CTx) offered any advantages for patients diagnosed with stage pT3N0 rectal cancer located in the proximal (upper) region following a complete total mesorectum excision (TME). METHODS: We retrospectively examined medical records of stage II/III rectal cancer patients who had undergone CTx or concurrent chemoradiation (CCRT) with IMRT after a successful TME. We juxtaposed a variety of survival outcomes across two patient cohorts. Each outcome was further classified according to Gunderson's risk stratification between proximal and distal (middle and low) rectal cancer patients, and we evaluated the factors associated with each outcome. RESULTS: The median follow-up duration was 4.9 years. Our research comprised 236 rectal adenocarcinoma patients treated at our institution between 2007 and 2019. They received either the CTx (n = 135) or the CCRT (n = 101) with 10-year locoregional recurrence-free survival (LRRFS) of 90.1% and 96.1%, respectively (p = 0.163). However, after performing multivariate adjustments, a pattern emerged hinting at a better LRRFS for the CCRT group (p = 0.052). Perforation had a strong correlation with locoregional recurrence. No significant differences were observed in other survival between the two treatment arms and their respective subgroups. The CCRT group witnessed significantly higher immediate and chronic complications with p = 0.007 and 0.009, respectively. The CCRT group had two secondary cancer-related fatalities (2%, one attributed to IMRT), and another reported by the CTx group (1%). The sole classified locoregional recurrence within the cohort of 37 individuals treated with CTx for proximal pT3N0 rectal cancer was, in fact, the development of sigmoid colon cancer. CONCLUSION: The results suggest that for patients with proximal pT3N0 rectal cancer post-TME, IMRT is better when not combined with CTx, except in highly perilous scenarios or those involving perforation.
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Radioterapia de Intensidade Modulada , Neoplasias Retais , Humanos , Radioterapia de Intensidade Modulada/efeitos adversos , Radioterapia de Intensidade Modulada/métodos , Estudos Retrospectivos , Recidiva Local de Neoplasia/patologia , Neoplasias Retais/patologia , Quimiorradioterapia/efeitos adversos , Quimiorradioterapia/métodos , Protocolos de Quimioterapia Combinada Antineoplásica/uso terapêutico , Resultado do Tratamento , Estadiamento de NeoplasiasRESUMO
The use of scaled-down micro-bumps in miniaturized consumer electronic products has led to the easy realization of full intermetallic solder bumps owing to the completion of the wetting layer. However, the direct contact of the intermetallic compounds (IMCs) with the adhesion layer may pose serious reliability concerns. In this study, the terminal reaction of the Ti adhesion layer with Cu-Sn IMCs was investigated by aging the micro-bumps at 200 °C. Although all of the micro-bumps transformed into intermetallic structures after aging, they exhibited a strong attachment to the Ti adhesion layer, which differs significantly from the Cr system where spalling of IMCs occurred during the solid-state reaction. Moreover, the difference in the diffusion rates between Cu and Sn might have induced void formation during aging. These voids progressed to the center of the bump through the depleting Cu layer. However, they neither affected the attachment between the IMCs and the adhesion layer nor reduced the strength of the bumps. In conclusion, the IMCs demonstrated better adhesive behavior with the Ti adhesion layer when compared to Cr, which has been used in previous studies.
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BACKGROUND: Surface-Enhanced Laser Desorption/Ionization Time-of-Flight Mass Spectrometry (SELDI-TOF-MS) is a frequently used technique for cancer biomarker research. The specificity of biomarkers detected by SELDI can be influenced by concomitant inflammation. This study aimed to increase detection accuracy using a two-stage analysis process. METHODS: Sera from 118 lung cancer patients, 72 healthy individuals, and 31 patients with inflammatory disease were randomly divided into training and testing groups by 3:2 ratio. In the training group, the traditional method of using SELDI profile analysis to directly distinguish lung cancer patients from sera was used. The two-stage analysis of distinguishing the healthy people and non-healthy patients (1st-stage) and then differentiating cancer patients from inflammatory disease patients (2nd-stage) to minimize the influence of inflammation was validated in the test group. RESULTS: In the test group, the one-stage method had 87.2% sensitivity, 37.5% specificity, and 64.4% accuracy. The two-stage method had lower sensitivity (> 70.1%) but statistically higher specificity (80%) and accuracy (74.7%). The predominantly expressed protein peak at 11480 Da was the primary splitter regardless of one- or two-stage analysis. This peak was suspected to be SAA (Serum Amyloid A) due to the similar m/z countered around this area. This hypothesis was further tested using an SAA ELISA assay. CONCLUSIONS: Inflammatory disease can severely interfere with the detection accuracy of SELDI profiles for lung cancer. Using a two-stage training process will improve the specificity and accuracy of detecting lung cancer.
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BACKGROUND: Pentraxin 3 (PTX3) plays an important role in innate immune responses and in inflammation disease. The aim of this study was to investigate the diagnostic and prognostic potential of PTX3 in pelvic inflammatory disease (PID) and correlate it with the severity and outcome of PID. METHODS: Blood specimens were collected from 64 patients with PID before and after treatment and 70 healthy controls and the plasma levels of PTX3 were measured using enzyme-linked immunosorbent assay (ELISA) kits. RESULTS: It was found that the plasma level of PTX3 expression was elevated in PID patients compared with healthy controls and decreased significantly after they received treatment. When the cut-off level of plasma PTX3 was set at 2.87 ng/mL, PTX3 had higher sensitivity (84.38%) and lower false-negative rate (15.63%) than CRP (79.69% and 20.31%, respectively) in predicting PID. The level of PTX3 also exhibited a significant correlation with length of hospital stay (r=0.581, p<0.001). CONCLUSIONS: Plasma PTX3 concentration not only predicts the presence of PID with lower false-negative rate than CRP, but plasma PTX3 concentration is also affiliated with the presence of tubo-ovarian abscess (TOA) and the length of hospital stay.
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Proteína C-Reativa/metabolismo , Doença Inflamatória Pélvica/diagnóstico , Componente Amiloide P Sérico/metabolismo , Proteína C-Reativa/análise , Ensaio de Imunoadsorção Enzimática , Feminino , Humanos , Doença Inflamatória Pélvica/metabolismo , Prognóstico , Padrões de Referência , Sensibilidade e Especificidade , Componente Amiloide P Sérico/análise , Índice de Gravidade de Doença , Resultado do TratamentoRESUMO
Extensive structural and functional studies have been carried out in the field of nucleocytoplasmic transport. Nuclear transport factors, such as Importin-α/-ß, recognize nuclear localization signals (NLSs) on cargo, and together with the small GTPase Ran, facilitate their nuclear localization. However, it is now emerging that binding of nuclear transport factors to NLSs not only mediates nuclear transport but also contributes to a variety of cellular functions in eukaryotes. Here, we describe recent advances that reveal how NLSs facilitate diverse cellular functions beyond nuclear transport activity. We review separately NLS-mediated regulatory mechanisms at different levels of biological organization, including (a) assembly of higher-order structures; (b) cellular organelle dynamics; and (c) modulation of cellular stress responses and viral infections. Finally, we provide mechanistic insights into how NLSs can regulate such a broad range of functions via their structural and biochemical properties.
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Transporte Ativo do Núcleo Celular/genética , Sinais de Localização Nuclear/genética , Viroses/genética , Proteína ran de Ligação ao GTP/genética , Humanos , Organelas/genética , Organelas/metabolismo , Estresse Fisiológico/genética , Viroses/virologiaRESUMO
To facilitate proper mitotic cell partitioning, the Golgi disassembles by suppressing vesicle fusion. However, the underlying mechanism has not been characterized previously. Here, we report a Ran pathway-independent attenuation mechanism that allows Importin-α (a nuclear transport factor) to suppress the vesicle fusion mediated by p115 (a vesicular tethering factor) and is required for mitotic Golgi disassembly. We demonstrate that Importin-α directly competes with p115 for interaction with the Golgi protein GM130. This interaction, promoted by a phosphate moiety on GM130, is independent of Importin-ß and Ran. A GM130 K34A mutant, in which the Importin-α-GM130 interaction is specifically disrupted, exhibited abundant Golgi puncta during metaphase. Importantly, a mutant showing enhanced p115-GM130 interaction presented proliferative defects and G2/M arrest, demonstrating that Importin-α-GM130 binding modulates the Golgi disassembly that governs mitotic progression. Our findings illuminate that the Ran and kinase-phosphatase pathways regulate multiple aspects of mitosis coordinated by Importin-α (e.g. spindle assembly, Golgi disassembly).
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Autoantígenos/metabolismo , Complexo de Golgi/metabolismo , Proteínas da Matriz do Complexo de Golgi/metabolismo , Proteínas de Membrana/metabolismo , Metáfase/fisiologia , Proteínas de Transporte Vesicular/metabolismo , alfa Carioferinas/metabolismo , Autoantígenos/genética , Cristalografia por Raios X , Pontos de Checagem da Fase G2 do Ciclo Celular , Células HEK293 , Humanos , Fusão de Membrana , Proteínas de Membrana/genética , Mitose/fisiologia , Fosforilação , Ligação Proteica , beta Carioferinas/metabolismo , Proteína ran de Ligação ao GTP/metabolismoRESUMO
Cardiovascular disease is the leading cause of morbidity and mortality in the world. Mutations in the FHL2 (Four and a half LIM domains protein 2) gene are associated with cardiomyopathy in patients. Here, we generated two homozygous knockout lines using CRISPR/Cas9-mediated ablation in a human embryonic stem cell (hESC) WA09 line. These knockout lines exhibit a normal karyotype without expressing FHL2 protein, while maintaining pluripotency and differentiation properties. These isogenic mutation lines will be provided as a disease model for cardiomyopathy studies and drug screening.
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Sistemas CRISPR-Cas/fisiologia , Células-Tronco Embrionárias Humanas/metabolismo , Proteínas com Homeodomínio LIM/genética , Proteínas Musculares/genética , Fatores de Transcrição/genética , Sistemas CRISPR-Cas/genética , Diferenciação Celular/genética , Diferenciação Celular/fisiologia , Linhagem Celular , Células Cultivadas , Éxons/genética , Técnicas de Inativação de Genes , Hepatócitos/metabolismo , Humanos , CariótipoRESUMO
Ran-guanosine triphosphatase orchestrates mitotic spindle assembly by modulation of the interaction between Importin-α/-ß and spindle assembly factors (SAFs). The inhibition of SAFs performed by importins needs to be done without much sequestration from abundant nuclear localization signal (NLS) -containing proteins. However, the molecular mechanisms that determine NLS-binding selectivity and that inhibit activity of Importin-ß-regulated SAFs (e.g., nuclear mitotic apparatus protein [NuMA]) remain undefined. Here, we present a crystal structure of the Importin-α-NuMA C terminus complex showing a novel binding pattern that accounts for selective NLS recognition. We demonstrate that, in the presence of Importin-α, Importin-ß inhibits the microtubule-binding function of NuMA. Further, we have identified a high-affinity microtubule-binding region that lies carboxyl-terminal to the NLS, which is sterically masked by Importin-ß on being bound by Importin-α. Our study provides mechanistic evidence of how Importin-α/-ß regulates the NuMA functioning required for assembly of higher-order microtubule structures, further illuminating how Ran-governed transport factors regulate diverse SAFs and accommodate various cell demands.