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1.
Proc Natl Acad Sci U S A ; 121(20): e2319115121, 2024 May 14.
Artículo en Inglés | MEDLINE | ID: mdl-38709931

RESUMEN

The endosomal sorting complexes required for transport (ESCRTs) are responsible for membrane remodeling in many cellular processes, such as multivesicular body biogenesis, viral budding, and cytokinetic abscission. ESCRT-III, the most abundant ESCRT subunit, assembles into flat spirals as the primed state, essential to initiate membrane invagination. However, the three-dimensional architecture of ESCRT-III flat spirals remained vague for decades due to highly curved filaments with a small diameter and a single preferred orientation on the membrane. Here, we unveiled that yeast Snf7, a component of ESCRT-III, forms flat spirals on the lipid monolayers using cryogenic electron microscopy. We developed a geometry-constrained Euler angle-assigned reconstruction strategy and obtained moderate-resolution structures of Snf7 flat spirals with varying curvatures. Our analyses showed that Snf7 subunits recline on the membrane with N-terminal motifs α0 as anchors, adopt an open state with fused α2/3 helices, and bend α2/3 gradually from the outer to inner parts of flat spirals. In all, we provide the orientation and conformations of ESCRT-III flat spirals on the membrane and unveil the underlying assembly mechanism, which will serve as the initial step in understanding how ESCRTs drive membrane abscission.


Asunto(s)
Microscopía por Crioelectrón , Complejos de Clasificación Endosomal Requeridos para el Transporte , Proteínas de Saccharomyces cerevisiae , Saccharomyces cerevisiae , Complejos de Clasificación Endosomal Requeridos para el Transporte/metabolismo , Complejos de Clasificación Endosomal Requeridos para el Transporte/química , Proteínas de Saccharomyces cerevisiae/metabolismo , Proteínas de Saccharomyces cerevisiae/química , Proteínas de Saccharomyces cerevisiae/ultraestructura , Saccharomyces cerevisiae/metabolismo , Membrana Celular/metabolismo
2.
Nucleus ; 15(1): 2349085, 2024 Dec.
Artículo en Inglés | MEDLINE | ID: mdl-38700207

RESUMEN

The ESCRT machinery plays a pivotal role in membrane-remodeling events across multiple cellular processes including nuclear envelope repair and reformation, nuclear pore complex surveillance, endolysosomal trafficking, and neuronal pruning. Alterations in ESCRT-III functionality have been associated with neurodegenerative diseases including Frontotemporal Dementia (FTD), Amyotrophic Lateral Sclerosis (ALS), and Alzheimer's Disease (AD). In addition, mutations in specific ESCRT-III proteins have been identified in FTD/ALS. Thus, understanding how disruptions in the fundamental functions of this pathway and its individual protein components in the human central nervous system (CNS) may offer valuable insights into mechanisms underlying neurodegenerative disease pathogenesis and identification of potential therapeutic targets. In this review, we discuss ESCRT components, dynamics, and functions, with a focus on the ESCRT-III pathway. In addition, we explore the implications of altered ESCRT-III function for neurodegeneration with a primary emphasis on nuclear surveillance and endolysosomal trafficking within the CNS.


Asunto(s)
Complejos de Clasificación Endosomal Requeridos para el Transporte , Enfermedades Neurodegenerativas , Humanos , Complejos de Clasificación Endosomal Requeridos para el Transporte/metabolismo , Enfermedades Neurodegenerativas/metabolismo , Enfermedades Neurodegenerativas/patología , Enfermedades Neurodegenerativas/genética , Animales , Núcleo Celular/metabolismo , Demencia Frontotemporal/metabolismo , Demencia Frontotemporal/patología , Demencia Frontotemporal/genética , Endosomas/metabolismo
3.
J Extracell Vesicles ; 13(5): e12431, 2024 May.
Artículo en Inglés | MEDLINE | ID: mdl-38711329

RESUMEN

The budding yeast Saccharomyces cerevisiae is a proven model organism for elucidating conserved eukaryotic biology, but to date its extracellular vesicle (EV) biology is understudied. Here, we show yeast transmit information through the extracellular medium that increases survival when confronted with heat stress and demonstrate the EV-enriched samples mediate this thermotolerance transfer. These samples contain vesicle-like particles that are exosome-sized and disrupting exosome biogenesis by targeting endosomal sorting complexes required for transport (ESCRT) machinery inhibits thermotolerance transfer. We find that Bro1, the yeast ortholog of the human exosome biomarker ALIX, is present in EV samples, and use Bro1 tagged with green fluorescent protein (GFP) to track EV release and uptake by endocytosis. Proteomics analysis reveals that heat shock protein 70 (HSP70) family proteins are enriched in EV samples that provide thermotolerance. We confirm the presence of the HSP70 ortholog stress-seventy subunit A2 (Ssa2) in EV samples and find that mutant yeast cells lacking SSA2 produce EVs but they fail to transfer thermotolerance. We conclude that Ssa2 within exosomes shared between yeast cells contributes to thermotolerance. Through this work, we advance Saccharomyces cerevisiae as an emerging model organism for elucidating molecular details of eukaryotic EV biology and establish a role for exosomes in heat stress and proteostasis that seems to be evolutionarily conserved.


Asunto(s)
Complejos de Clasificación Endosomal Requeridos para el Transporte , Exosomas , Vesículas Extracelulares , Proteínas de Saccharomyces cerevisiae , Saccharomyces cerevisiae , Termotolerancia , Saccharomyces cerevisiae/metabolismo , Vesículas Extracelulares/metabolismo , Proteínas de Saccharomyces cerevisiae/metabolismo , Proteínas de Saccharomyces cerevisiae/genética , Complejos de Clasificación Endosomal Requeridos para el Transporte/metabolismo , Exosomas/metabolismo , Proteínas HSP70 de Choque Térmico/metabolismo , Respuesta al Choque Térmico , Proteómica/métodos
4.
Nat Commun ; 15(1): 4023, 2024 May 13.
Artículo en Inglés | MEDLINE | ID: mdl-38740816

RESUMEN

Abscission is the final stage of cytokinesis, which cleaves the intercellular bridge (ICB) connecting two daughter cells. Abscission requires tight control of the recruitment and polymerization of the Endosomal Protein Complex Required for Transport-III (ESCRT-III) components. We explore the role of post-translational modifications in regulating ESCRT dynamics. We discover that SMYD2 methylates the lysine 6 residue of human CHMP2B, a key ESCRT-III component, at the ICB, impacting the dynamic relocation of CHMP2B to sites of abscission. SMYD2 loss-of-function (genetically or pharmacologically) causes CHMP2B hypomethylation, delayed CHMP2B polymerization and delayed abscission. This is phenocopied by CHMP2B lysine 6 mutants that cannot be methylated. Conversely, SMYD2 gain-of-function causes CHMP2B hypermethylation and accelerated abscission, specifically in cells undergoing cytokinetic challenges, thereby bypassing the abscission checkpoint. Additional experiments highlight the importance of CHMP2B methylation beyond cytokinesis, namely during ESCRT-III-mediated HIV-1 budding. We propose that lysine methylation signaling fine-tunes the ESCRT-III machinery to regulate the timing of cytokinetic abscission and other ESCRT-III dependent functions.


Asunto(s)
Citocinesis , Complejos de Clasificación Endosomal Requeridos para el Transporte , Complejos de Clasificación Endosomal Requeridos para el Transporte/metabolismo , Complejos de Clasificación Endosomal Requeridos para el Transporte/genética , Humanos , Metilación , Células HeLa , N-Metiltransferasa de Histona-Lisina/metabolismo , N-Metiltransferasa de Histona-Lisina/genética , VIH-1/metabolismo , VIH-1/genética , VIH-1/fisiología , Lisina/metabolismo , Procesamiento Proteico-Postraduccional
5.
Curr Microbiol ; 81(7): 173, 2024 May 15.
Artículo en Inglés | MEDLINE | ID: mdl-38750329

RESUMEN

The ability of fungi to effectively sense and internalize signals related to extracellular changing environments is essential for survival. This adaptability is particularly important for fungal pathogens of humans and plants that must sense and respond to drastic environmental changes when colonizing their hosts. One of the most important physicochemical factors affecting fungal growth and development is the pH. Ascomycota fungal species possess mechanisms such as the Pal/Rim pathway for external pH sensing and adaptation. However, the conservation of this mechanism in other fungi, such as Ustilaginomycetes is still little studied. To overcome this knowledge gap, we used a comparative genomic approach to explore the conservation of the Pal/Rim pathway in the 13 best sequenced and annotated Ustilaginomycetes. Our findings reveal that the Rim proteins and the Endosomal Sorting Complex Required for Transport (ESCRT) proteins are conserved in Ustilaginomycetes. They conserve the canonical domains present in Pal/Rim and ESCRT proteins of Ascomycota. This study sheds light on the molecular mechanisms used by these fungi for responding to extracellular stresses such as the pH, and open the door to further experimentations for understanding the molecular bases of the signaling in Ustilaginomycetes.


Asunto(s)
Proteínas Fúngicas , Proteínas Fúngicas/genética , Proteínas Fúngicas/metabolismo , Concentración de Iones de Hidrógeno , Transducción de Señal , Ascomicetos/genética , Ascomicetos/metabolismo , Complejos de Clasificación Endosomal Requeridos para el Transporte/metabolismo , Complejos de Clasificación Endosomal Requeridos para el Transporte/genética , Filogenia
6.
PLoS Biol ; 22(4): e3002327, 2024 Apr.
Artículo en Inglés | MEDLINE | ID: mdl-38687820

RESUMEN

Mutations in the human AAA-ATPase VPS4 isoform, VPS4A, cause severe neurodevelopmental defects and congenital dyserythropoietic anemia (CDA). VPS4 is a crucial component of the endosomal sorting complex required for transport (ESCRT) system, which drives membrane remodeling in numerous cellular processes, including receptor degradation, cell division, and neural pruning. Notably, while most organisms encode for a single VPS4 gene, human cells have 2 VPS4 paralogs, namely VPS4A and VPS4B, but the functional differences between these paralogs is mostly unknown. Here, we set out to investigate the role of the human VPS4 paralogs in cytokinetic abscission using a series of knockout cell lines. We found that VPS4A and VPS4B hold both overlapping and distinct roles in abscission. VPS4A depletion resulted in a more severe abscission delay than VPS4B and was found to be involved in earlier stages of abscission. Moreover, VPS4A and a monomeric-locked VPS4A mutant bound the abscission checkpoint proteins CHMP4C and ANCHR, while VPS4B did not, indicating a regulatory role for the VPS4A isoform in abscission. Depletion of VTA1, a co-factor of VPS4, disrupted VPS4A-ANCHR interactions and accelerated abscission, suggesting that VTA1 is also involved in the abscission regulation. Our findings reveal a dual role for VPS4A in abscission, one that is canonical and can be compensated by VPS4B, and another that is regulatory and may be delivered by its monomeric form. These observations provide a potential mechanistic explanation for the neurodevelopmental defects and other related disorders reported in VPS4A-mutated patients with a fully functional VPS4B paralog.


Asunto(s)
ATPasas Asociadas con Actividades Celulares Diversas , Citocinesis , Complejos de Clasificación Endosomal Requeridos para el Transporte , ATPasas de Translocación de Protón Vacuolares , Humanos , Complejos de Clasificación Endosomal Requeridos para el Transporte/metabolismo , Complejos de Clasificación Endosomal Requeridos para el Transporte/genética , ATPasas Asociadas con Actividades Celulares Diversas/metabolismo , ATPasas Asociadas con Actividades Celulares Diversas/genética , ATPasas de Translocación de Protón Vacuolares/metabolismo , ATPasas de Translocación de Protón Vacuolares/genética , Células HeLa , Isoformas de Proteínas/metabolismo , Isoformas de Proteínas/genética
7.
Cells ; 13(8)2024 Apr 09.
Artículo en Inglés | MEDLINE | ID: mdl-38667270

RESUMEN

The Sit4 protein phosphatase plays a key role in orchestrating various cellular processes essential for maintaining cell viability during aging. We have previously shown that SIT4 deletion promotes vacuolar acidification, mitochondrial derepression, and oxidative stress resistance, increasing yeast chronological lifespan. In this study, we performed a proteomic analysis of isolated vacuoles and yeast genetic interaction analysis to unravel how Sit4 influences vacuolar and mitochondrial function. By employing high-resolution mass spectrometry, we show that sit4Δ vacuolar membranes were enriched in Vps27 and Hse1, two proteins that are part of the endosomal sorting complex required for transport-0. In addition, SIT4 exhibited a negative genetic interaction with VPS27, as sit4∆vps27∆ double mutants had a shortened lifespan compared to sit4∆ and vps27∆ single mutants. Our results also show that Vps27 did not increase sit4∆ lifespan by improving protein trafficking or vacuolar sorting pathways. However, Vps27 was critical for iron homeostasis and mitochondrial function in sit4∆ cells, as sit4∆vps27∆ double mutants exhibited high iron levels and impaired mitochondrial respiration. These findings show, for the first time, cross-talk between Sit4 and Vps27, providing new insights into the mechanisms governing chronological lifespan.


Asunto(s)
Mitocondrias , Proteína Fosfatasa 2 , Proteínas de Saccharomyces cerevisiae , Saccharomyces cerevisiae , Vacuolas , Saccharomyces cerevisiae/metabolismo , Saccharomyces cerevisiae/genética , Proteínas de Saccharomyces cerevisiae/metabolismo , Proteínas de Saccharomyces cerevisiae/genética , Mitocondrias/metabolismo , Vacuolas/metabolismo , Hierro/metabolismo , Transporte de Proteínas , Complejos de Clasificación Endosomal Requeridos para el Transporte/metabolismo , Complejos de Clasificación Endosomal Requeridos para el Transporte/genética , Mutación/genética
8.
Proc Natl Acad Sci U S A ; 121(17): e2317680121, 2024 Apr 23.
Artículo en Inglés | MEDLINE | ID: mdl-38635626

RESUMEN

The endosomal sorting complex required for transport (ESCRT) machinery constitutes multisubunit protein complexes that play an essential role in membrane remodeling and trafficking. ESCRTs regulate a wide array of cellular processes, including cytokinetic abscission, cargo sorting into multivesicular bodies (MVBs), membrane repair, and autophagy. Given the versatile functionality of ESCRTs, and the intricate organizational structure of the ESCRT machinery, the targeted modulation of distinct ESCRT complexes is considerably challenging. This study presents a pseudonatural product targeting IST1-CHMP1B within the ESCRT-III complexes. The compound specifically disrupts the interaction between IST1 and CHMP1B, thereby inhibiting the formation of IST1-CHMP1B copolymers essential for normal-topology membrane scission events. While the compound has no impact on cytokinesis, MVB sorting, or biogenesis of extracellular vesicles, it rapidly inhibits transferrin receptor recycling in cells, resulting in the accumulation of transferrin in stalled sorting endosomes. Stalled endosomes become decorated by lipidated LC3, suggesting a link between noncanonical LC3 lipidation and inhibition of the IST1-CHMP1B complex.


Asunto(s)
Complejos de Clasificación Endosomal Requeridos para el Transporte , Endosomas , Endosomas/metabolismo , Complejos de Clasificación Endosomal Requeridos para el Transporte/metabolismo , Transporte de Proteínas , Cuerpos Multivesiculares/metabolismo
9.
J Mol Cell Cardiol ; 190: 35-47, 2024 May.
Artículo en Inglés | MEDLINE | ID: mdl-38593639

RESUMEN

BACKGROUND: Exosomes released by cardiomyocytes are essential mediators of intercellular communications within the heart, and various exosomal proteins and miRNAs are associated with cardiovascular diseases. However, whether the endosomal sorting complex required for transport (ESCRT) and its key component Alix is required for exosome biogenesis within cardiomyocyte remains poorly understood. METHODS: Super-resolution imaging was performed to investigate the subcellular location of Alix and multivesicular body (MVB) in primary cardiomyocytes. Cardiomyocyte-specific Alix-knockout mice were generated using AAV9/CRISPR/Cas9-mediated in vivo gene editing. A stable Alix-knockdown H9c2 cardiomyocyte line was constructed through lentiviral-mediated delivery of short hairpin RNA. In order to determine the role of Alix in controlling exosome biogenesis, exosomes from cardiomyocyte-specific Alix-knockout mice plasma and Alix-knockdown H9c2 culture medium were isolated and examined by western blot, NTA analysis and transmission electron microscopy. Biochemical and immunofluorescence analysis were performed to determine the role of ESCRT machinery in regulating MVB formation. Lastly, transverse aortic constriction (TAC)-induced cardiac pressure overload model was established to further explore the role of Alix-mediated exosome biogenesis under stress conditions. RESULTS: A significant proportion of Alix localized to the MVB membrane within cardiomyocytes. Genetic deletion of Alix in murine heart resulted in a reduction of plasma exosome content without affecting cardiac structure or contractile function. Consistently, the downregulation of Alix in H9c2 cardiomyocyte line also suppressed the biogenesis of exosomes. We found the defective ESCRT machinery and suppressed MVB formation upon Alix depletion caused compromised exosome biogenesis. Remarkably, TAC-induced cardiac pressure overload led to increased Alix, MVB levels, and elevated plasma exosome content, which could be totally abolished by Alix deletion. CONCLUSION: These results establish Alix as an essential and stress-sensitive regulator of cardiac exosome biogenesis and the findings may yield valuable therapeutic implications.


Asunto(s)
Complejos de Clasificación Endosomal Requeridos para el Transporte , Exosomas , Ratones Noqueados , Miocitos Cardíacos , Estrés Fisiológico , Miocitos Cardíacos/metabolismo , Animales , Exosomas/metabolismo , Complejos de Clasificación Endosomal Requeridos para el Transporte/metabolismo , Complejos de Clasificación Endosomal Requeridos para el Transporte/genética , Ratones , Cuerpos Multivesiculares/metabolismo , Línea Celular , Proteínas de Unión al Calcio/metabolismo , Proteínas de Unión al Calcio/genética , Ratas
10.
Int J Biol Macromol ; 267(Pt 1): 131453, 2024 May.
Artículo en Inglés | MEDLINE | ID: mdl-38588842

RESUMEN

Enterovirus 71 (EV71) causes hand-foot-and-mouth disease (HFMD), neurological complications, and even fatalities in infants. Clinically, the increase of extracellular vesicles (EVs) in EV71 patients' serum was highly associated with the severity of HFMD. EV71 boosts EVs biogenesis in an endosomal sorting complex required for transport (ESCRT)-dependent manner to facilitate viral replication. Yet, the impact of EVs-derived from ESCRT-independent pathway on EV71 replication and pathogenesis is highly concerned. Here, we assessed the effects of EV71-induced EVs from ESCRT-independent pathway on viral replication and pathogenesis by GW4869, a neutral sphingomyelinase inhibitor. Detailly, in EV71-infected mice, blockade of the biogenesis of tissue-derived EVs in the presence of GW4869 restored body weight loss, attenuated clinical scores, and improved survival rates. Furthermore, GW4869 dampens EVs biogenesis to reduce viral load and pathogenesis in multiple tissues of EV71-infected mice. Consistently, GW4869 treatment in a human intestinal epithelial HT29 cells decreased the biogenesis of EVs, in which the progeny EV71 particle was cloaked, leading to the reduction of viral infection and replication. Collectively, GW4869 inhibits EV71-induced EVs in an ESCRT-independent pathway and ultimately suppresses EV71 replication and pathogenesis. Our study provides a novel strategy for the development of therapeutic agents in the treatment for EV71-associated HFMD.


Asunto(s)
Compuestos de Anilina , Complejos de Clasificación Endosomal Requeridos para el Transporte , Enterovirus Humano A , Vesículas Extracelulares , Replicación Viral , Animales , Replicación Viral/efectos de los fármacos , Enterovirus Humano A/efectos de los fármacos , Enterovirus Humano A/fisiología , Ratones , Vesículas Extracelulares/metabolismo , Complejos de Clasificación Endosomal Requeridos para el Transporte/metabolismo , Humanos , Compuestos de Bencilideno/farmacología , Infecciones por Enterovirus/virología , Infecciones por Enterovirus/tratamiento farmacológico , Infecciones por Enterovirus/metabolismo , Carga Viral/efectos de los fármacos , Femenino
11.
Adv Sci (Weinh) ; 11(18): e2308312, 2024 May.
Artículo en Inglés | MEDLINE | ID: mdl-38447164

RESUMEN

Here, an in vitro characterization of a family of prazole derivatives that covalently bind to the C73 site on Tsg101 and assay their ability to inhibit viral particle production is presented. Structurally, increased steric bulk on the 4-pyridyl of the prazole expands the prazole site on the UEV domain toward the ß-hairpin in the Ub-binding site and is coupled to increased inhibition of virus-like particle production in HIV-1. Increased bulk also increased toxicity, which is alleviated by increasing flexibility. Further, the formation of a novel secondary Tsg101 adduct for several of the tested compounds and the commercial drug lansoprazole. The secondary adduct involved the loss of the 4-pyridyl substituent to form an irreversible species, with implications for increasing the half-life of the active species or its specificity toward Tsg101 UEV. It is also determined that sulfide derivatives display effective viral inhibition, presumably through cellular sulfoxidation, allowing for delayed conversion within the cellular environment, and identify SARS-COV-2 as a target of prazole inhibition. These results open multiple avenues for the design of prazole derivatives for antiviral applications.


Asunto(s)
Antivirales , VIH-1 , Antivirales/farmacología , Antivirales/química , Humanos , VIH-1/efectos de los fármacos , Complejos de Clasificación Endosomal Requeridos para el Transporte/metabolismo , Complejos de Clasificación Endosomal Requeridos para el Transporte/química , Relación Estructura-Actividad , Tratamiento Farmacológico de COVID-19 , Replicación Viral/efectos de los fármacos
12.
Development ; 151(8)2024 Apr 15.
Artículo en Inglés | MEDLINE | ID: mdl-38546617

RESUMEN

Abscission is the final step of cytokinesis that allows the physical separation of sister cells through the scission of the cellular membrane. This deformation is driven by ESCRT-III proteins, which can bind membranes and form dynamic helices. A crucial step in abscission is the recruitment of ESCRT-III proteins at the right time and place. Alix is one of the best characterized proteins that recruits ESCRT-III proteins from yeast to mammals. However, recent studies in vivo have revealed that pathways acting independently or redundantly with Alix are also required at abscission sites in different cellular contexts. Here, we show that Lgd acts redundantly with Alix to properly localize ESCRT-III to the abscission site in germline stem cells (GSCs) during Drosophila oogenesis. We further demonstrate that Lgd is phosphorylated at multiple sites by the CycB/Cdk1 kinase. We found that these phosphorylation events potentiate the activity of Shrub, a Drosophila ESCRT-III, during abscission of GSCs. Our study reveals that redundancy between Lgd and Alix, and coordination with the cell cycle kinase Cdk1, confers robust and timely abscission of Drosophila germline stem cells.


Asunto(s)
Proteínas de Drosophila , Complejos de Clasificación Endosomal Requeridos para el Transporte , Células Germinativas , Células Madre , Animales , Proteína Quinasa CDC2/genética , Proteína Quinasa CDC2/metabolismo , Ciclina B , Citocinesis/genética , Drosophila/metabolismo , Proteínas de Drosophila/genética , Proteínas de Drosophila/metabolismo , Complejos de Clasificación Endosomal Requeridos para el Transporte/genética , Complejos de Clasificación Endosomal Requeridos para el Transporte/metabolismo , Células Germinativas/metabolismo , Mamíferos/metabolismo , Células Madre/metabolismo
13.
PLoS Pathog ; 20(3): e1012103, 2024 Mar.
Artículo en Inglés | MEDLINE | ID: mdl-38489378

RESUMEN

Alphacoronaviruses are the primary coronaviruses responsible for causing severe economic losses in the pig industry with the potential to cause human outbreaks. Currently, extensive studies have reported the essential role of endosomal sorting and transport complexes (ESCRT) in the life cycle of enveloped viruses. However, very little information is available about which ESCRT components are crucial for alphacoronaviruses infection. By using RNA interference in combination with Co-immunoprecipitation, as well as fluorescence and electron microscopy approaches, we have dissected the role of ALIX and TSG101 for two porcine alphacoronavirus cellular entry and replication. Results show that infection by two porcine alphacoronaviruses, including porcine epidemic diarrhea virus (PEDV) and porcine enteric alphacoronavirus (PEAV), is dramatically decreased in ALIX- or TSG101-depleted cells. Furthermore, PEDV entry significantly increases the interaction of ALIX with caveolin-1 (CAV1) and RAB7, which are crucial for viral endocytosis and lysosomal transport, however, does not require TSG101. Interestingly, PEAV not only relies on ALIX to regulate viral endocytosis and lysosomal transport, but also requires TSG101 to regulate macropinocytosis. Besides, ALIX and TSG101 are recruited to the replication sites of PEDV and PEAV where they become localized within the endoplasmic reticulum and virus-induced double-membrane vesicles. PEDV and PEAV replication were significantly inhibited by depletion of ALIX and TSG101 in Vero cells or primary jejunal epithelial cells, indicating that ALIX and TSG101 are crucial for PEDV and PEAV replication. Collectively, these data highlight the dual role of ALIX and TSG101 in the entry and replication of two porcine alphacoronaviruses. Thus, ESCRT proteins could serve as therapeutic targets against two porcine alphacoronaviruses infection.


Asunto(s)
Alphacoronavirus , Proteínas de Unión al Calcio , Virus de la Diarrea Epidémica Porcina , Animales , Alphacoronavirus/metabolismo , Línea Celular , Chlorocebus aethiops , Complejos de Clasificación Endosomal Requeridos para el Transporte/metabolismo , Células Epiteliales/metabolismo , Virus de la Diarrea Epidémica Porcina/metabolismo , Porcinos , Células Vero , Replicación Viral , Proteínas de Unión al Calcio/metabolismo
14.
Commun Biol ; 7(1): 334, 2024 Mar 15.
Artículo en Inglés | MEDLINE | ID: mdl-38491121

RESUMEN

VPS37A, an ESCRT-I complex component, is required for recruiting a subset of ESCRT proteins to the phagophore for autophagosome closure. However, the mechanism by which VPS37A is targeted to the phagophore remains obscure. Here, we demonstrate that the VPS37A N-terminal domain exhibits selective interactions with highly curved membranes, mediated by two membrane-interacting motifs within the disordered regions surrounding its Ubiquitin E2 variant-like (UEVL) domain. Site-directed mutations of residues in these motifs disrupt ESCRT-I localization to the phagophore and result in defective phagophore closure and compromised autophagic flux in vivo, highlighting their essential role during autophagy. In conjunction with the UEVL domain, we postulate that these motifs guide a functional assembly of the ESCRT machinery at the highly curved tip of the phagophore for autophagosome closure. These results advance the notion that the distinctive membrane architecture of the cup-shaped phagophore spatially regulates autophagosome biogenesis.


Asunto(s)
Autofagosomas , Autofagia , Autofagosomas/metabolismo , Autofagia/fisiología , Membranas Intracelulares/metabolismo , Endosomas/metabolismo , Complejos de Clasificación Endosomal Requeridos para el Transporte/genética , Complejos de Clasificación Endosomal Requeridos para el Transporte/metabolismo
15.
Nat Commun ; 15(1): 1949, 2024 Mar 02.
Artículo en Inglés | MEDLINE | ID: mdl-38431632

RESUMEN

Cell division is completed by the abscission of the intercellular bridge connecting the daughter cells. Abscission requires the polymerization of an ESCRT-III cone close to the midbody to both recruit the microtubule severing enzyme spastin and scission the plasma membrane. Here, we found that the microtubule and the membrane cuts are two separate events that are regulated differently. Using HeLa cells, we uncovered that the F-actin disassembling protein Cofilin-1 controls the disappearance of a transient pool of branched F-actin which is precisely assembled at the tip of the ESCRT-III cone shortly before the microtubule cut. Functionally, Cofilin-1 and Arp2/3-mediated branched F-actin favor abscission by promoting local severing of the microtubules but do not participate later in the membrane scission event. Mechanistically, we propose that branched F-actin functions as a physical barrier that limits ESCRT-III cone elongation and thereby favors stable spastin recruitment. Our work thus reveals that F-actin controls the timely and local disassembly of microtubules required for cytokinetic abscission.


Asunto(s)
Actinas , Microtúbulos , Humanos , Actinas/metabolismo , Células HeLa , Espastina/metabolismo , Microtúbulos/metabolismo , Citocinesis , Complejos de Clasificación Endosomal Requeridos para el Transporte/metabolismo , Factores Despolimerizantes de la Actina/metabolismo
16.
J Biol Chem ; 300(3): 105715, 2024 Mar.
Artículo en Inglés | MEDLINE | ID: mdl-38309503

RESUMEN

NEDD4L is a HECT-type E3 ligase that catalyzes the addition of ubiquitin to intracellular substrates such as the cardiac voltage-gated sodium channel, NaV1.5. The intramolecular interactions of NEDD4L regulate its enzymatic activity which is essential for proteostasis. For NaV1.5, this process is critical as alterations in Na+ current is involved in cardiac diseases including arrhythmias and heart failure. In this study, we perform extensive biochemical and functional analyses that implicate the C2 domain and the first WW-linker (1,2-linker) in the autoregulatory mechanism of NEDD4L. Through in vitro and electrophysiological experiments, the NEDD4L 1,2-linker was determined to be important in substrate ubiquitination of NaV1.5. We establish the preferred sites of ubiquitination of NEDD4L to be in the second WW-linker (2,3-linker). Interestingly, NEDD4L ubiquitinates the cytoplasmic linker between the first and second transmembrane domains of the channel (DI-DII) of NaV1.5. Moreover, we design a genetically encoded modulator of Nav1.5 that achieves Na+ current reduction using the NEDD4L HECT domain as cargo of a NaV1.5-binding nanobody. These investigations elucidate the mechanisms regulating the NEDD4 family and furnish a new molecular framework for understanding NaV1.5 ubiquitination.


Asunto(s)
Complejos de Clasificación Endosomal Requeridos para el Transporte , Canal de Sodio Activado por Voltaje NAV1.5 , Ubiquitina-Proteína Ligasas Nedd4 , Ubiquitinación , Complejos de Clasificación Endosomal Requeridos para el Transporte/metabolismo , Ubiquitina-Proteína Ligasas Nedd4/genética , Ubiquitina-Proteína Ligasas Nedd4/metabolismo , Ubiquitina/metabolismo , Humanos , Canal de Sodio Activado por Voltaje NAV1.5/metabolismo , Células HEK293
17.
Cell Rep ; 43(3): 113818, 2024 Mar 26.
Artículo en Inglés | MEDLINE | ID: mdl-38402586

RESUMEN

Intricate cerebral cortex formation is orchestrated by the precise behavior and division dynamics of radial glial cells (RGCs). Endocytosis functions in the recycling and remodeling of adherens junctions (AJs) in response to changes in RGC activity and function. Here, we show that conditional disruption of ubiquitin-associated protein 1 (UBAP1), a component of endosomal sorting complex required for transport (ESCRT), causes severe brain dysplasia and prenatal ventriculomegaly. UBAP1 depletion disrupts the AJs and polarity of RGCs, leading to failure of apically directed interkinetic nuclear migration. Accordingly, UBAP1 knockout or knockdown results in reduced proliferation and precocious differentiation of neural progenitor cells. Mechanistically, UBAP1 regulates the expression and surface localization of cell adhesion molecules, and ß-catenin over-expression significantly rescues the phenotypes of Ubap1 knockdown in vivo. Our study reveals a critical physiological role of the ESCRT machinery in cortical neurogenesis by regulating AJs of RGCs.


Asunto(s)
Complejos de Clasificación Endosomal Requeridos para el Transporte , Células Ependimogliales , Femenino , Embarazo , Humanos , Células Ependimogliales/metabolismo , Complejos de Clasificación Endosomal Requeridos para el Transporte/metabolismo , Ubiquitina/metabolismo , Uniones Adherentes/metabolismo , Corteza Cerebral/metabolismo , Neurogénesis , Proteínas Portadoras/metabolismo
18.
Mol Biol Cell ; 35(4): ar48, 2024 Apr 01.
Artículo en Inglés | MEDLINE | ID: mdl-38335450

RESUMEN

Nuclear envelope reassembly during the final stages of each mitosis depends on disassembling spindle microtubules without disrupting chromosome separation. This process involves the transient recruitment of the ESCRT-III complex and spastin, a microtubule-severing AAA (ATPases associated with diverse cellular activities) mechanoenzyme, to late-anaphase chromosomes. However, dissecting mechanisms underlying these rapid processes, which can be completed within minutes, has been difficult. Here, we combine fast-acting chemical inhibitors with live-cell imaging and find that spindle microtubules, along with spastin activity, regulate the number and lifetimes of spastin foci at anaphase chromosomes. Unexpectedly, spastin inhibition impedes chromosome separation, but does not alter the anaphase localization dynamics of CHMP4B, an ESCRT-III protein, or increase γ-H2AX foci, a DNA damage marker. We show spastin inhibition increases the frequency of lamin-lined nuclear microtunnels that can include microtubules penetrating the nucleus. Our findings suggest failure to sever spindle microtubules impedes chromosome separation, yet reforming nuclear envelopes can topologically accommodate persistent microtubules ensuring nuclear DNA is not damaged or exposed to cytoplasm.


Asunto(s)
Anafase , Microtúbulos , Espastina/metabolismo , Microtúbulos/metabolismo , Cromosomas/metabolismo , Complejos de Clasificación Endosomal Requeridos para el Transporte/metabolismo
19.
Bioessays ; 46(4): e2300230, 2024 Apr.
Artículo en Inglés | MEDLINE | ID: mdl-38412391

RESUMEN

In circulation, T cells are spherical with selectin enriched dynamic microvilli protruding from the surface. Following extravasation, these microvilli serve another role, continuously surveying their environment for antigen in the form of peptide-MHC (pMHC) expressed on the surface of antigen presenting cells (APCs). Upon recognition of their cognate pMHC, the microvilli are initially stabilized and then flatten into F-actin dependent microclusters as the T cell spreads over the APC. Within 1-5 min, clathrin is recruited by the ESCRT-0 component Hrs to mediate release of T cell receptor (TCR) loaded vesicles directly from the plasma membrane by clathrin and ESCRT-mediated ectocytosis (CEME). After 5-10 min, Hrs is displaced by the endocytic clathrin adaptor epsin-1 to induce clathrin-mediated trans-endocytosis (CMTE) of TCR-pMHC conjugates. Here we discuss some of the functional properties of the clathrin machinery which enables it to control these topologically opposite modes of membrane transfer at the immunological synapse, and how this might be regulated during T cell activation.


Asunto(s)
Clatrina , Linfocitos T , Clatrina/metabolismo , Células Presentadoras de Antígenos/metabolismo , Receptores de Antígenos de Linfocitos T , Endocitosis/fisiología , Complejos de Clasificación Endosomal Requeridos para el Transporte/metabolismo , Comunicación
20.
Nat Commun ; 15(1): 1021, 2024 Feb 03.
Artículo en Inglés | MEDLINE | ID: mdl-38310114

RESUMEN

The epidermal growth factor receptor (EGFR) plays important roles in multiple cellular events, including growth, differentiation, and motility. A major mechanism of downregulating EGFR function involves its endocytic transport to the lysosome. Sorting of proteins into intracellular pathways involves cargo adaptors recognizing sorting signals on cargo proteins. A dileucine-based sorting signal has been identified previously for the sorting of endosomal EGFR to the lysosome, but a cargo adaptor that recognizes this signal remains unknown. Here, we find that phosphoglycerate kinase 1 (PGK1) is recruited to endosomal membrane upon its phosphorylation, where it binds to the dileucine sorting signal in EGFR to promote the lysosomal transport of this receptor. We also elucidate two mechanisms that act in concert to promote PGK1 recruitment to endosomal membrane, a lipid-based mechanism that involves phosphatidylinositol 4,5-bisphosphate [PI(4,5)P2] and a protein-based mechanism that involves hepatocyte growth factor receptor substrate (Hrs). These findings reveal an unexpected function for a metabolic enzyme and advance the mechanistic understanding of how EGFR is transported to the lysosome.


Asunto(s)
Receptores ErbB , Fosfoglicerato Quinasa , Fosfoglicerato Quinasa/metabolismo , Receptores ErbB/metabolismo , Endosomas/metabolismo , Proteínas/metabolismo , Lisosomas/metabolismo , Transporte de Proteínas/fisiología , Complejos de Clasificación Endosomal Requeridos para el Transporte/metabolismo
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