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1.
Biophys Chem ; 310: 107255, 2024 Jul.
Artículo en Inglés | MEDLINE | ID: mdl-38728808

RESUMEN

In solution NMR, chemical shift perturbation (CSP) experiments are widely employed to study intermolecular interactions. However, excluding the nonsignificant peak shift is difficult because little is known about errors in CSP. Here, to address this issue, we introduce a method for estimating errors in CSP based on the noise level. First, we developed a technique that involves line shape fitting to estimate errors in peak position via Monte Carlo simulations. Second, this technique was applied to estimate errors in CSP. In intermolecular interaction analysis of VAP-A with SNX2, error estimation of CSP enabled the evaluation of small but significant changes in peak position and yielded detailed insights that are unattainable with conventional CSP analysis. Third, this technique was successfully applied to estimate errors in residual dipolar couplings. In conclusion, our error estimation method improves CSP analysis by excluding the nonsignificant peak shift.


Asunto(s)
Método de Montecarlo , Nexinas de Clasificación/química , Resonancia Magnética Nuclear Biomolecular , Espectroscopía de Resonancia Magnética/métodos
2.
Cancer Lett ; 592: 216953, 2024 Jun 28.
Artículo en Inglés | MEDLINE | ID: mdl-38729557

RESUMEN

TGFBR2, a key regulator of the TGFß signaling pathway, plays a crucial role in gastric cancer (GC) metastasis through its endosomal recycling process. Despite its importance, the mechanisms governing this process remain unclear. Here, we identify integrin ß5 (ITGB5) as a critical mediator that promotes TGFBR2 endosomal recycling. Our study reveals elevated expression of ITGB5 in GC, particularly in metastatic cases, correlating with poor patient outcomes. Knockdown of ITGB5 impairs GC cell metastasis both in vitro and in vivo. Mechanistically, ITGB5 facilitates epithelial-mesenchymal transition mediated by TGFß signaling, thereby enhancing GC metastasis. Acting as a scaffold, ITGB5 interacts with TGFBR2 and SNX17, facilitating SNX17-mediated endosomal recycling of TGFBR2 and preventing lysosomal degradation, thereby maintaining its surface distribution on tumor cells. Notably, TGFß signaling directly upregulates ITGB5 expression, establishing a positive feedback loop that exacerbates GC metastasis. Our findings shed light on the role of ITGB5 in promoting GC metastasis through SNX17-mediated endosomal recycling of TGFBR2, providing insights for the development of targeted cancer therapies.


Asunto(s)
Endosomas , Transición Epitelial-Mesenquimal , Receptor Tipo II de Factor de Crecimiento Transformador beta , Transducción de Señal , Neoplasias Gástricas , Receptor Tipo II de Factor de Crecimiento Transformador beta/genética , Receptor Tipo II de Factor de Crecimiento Transformador beta/metabolismo , Neoplasias Gástricas/patología , Neoplasias Gástricas/genética , Neoplasias Gástricas/metabolismo , Humanos , Endosomas/metabolismo , Animales , Línea Celular Tumoral , Cadenas beta de Integrinas/metabolismo , Cadenas beta de Integrinas/genética , Nexinas de Clasificación/genética , Nexinas de Clasificación/metabolismo , Ratones , Metástasis de la Neoplasia , Regulación Neoplásica de la Expresión Génica , Factor de Crecimiento Transformador beta/metabolismo
3.
Int J Mol Sci ; 25(7)2024 Apr 07.
Artículo en Inglés | MEDLINE | ID: mdl-38612903

RESUMEN

Proteins of the sorting nexin (SNX) family present a modular structural architecture with a phox homology (PX) phosphoinositide (PI)-binding domain and additional PX structural domains, conferring to them a wide variety of vital eukaryotic cell's functions, from signal transduction to membrane deformation and cargo binding. Although SNXs are well studied in human and yeasts, they are poorly investigated in protists. Herein, is presented the characterization of the first SNX identified in Leishmania protozoan parasites encoded by the LdBPK_352470 gene. In silico secondary and tertiary structure prediction revealed a PX domain on the N-terminal half and a Bin/amphiphysin/Rvs (BAR) domain on the C-terminal half of this protein, with these features classifying it in the SNX-BAR subfamily of SNXs. We named the LdBPK_352470.1 gene product LdSNXi, as it is the first SNX identified in Leishmania (L.) donovani. Its expression was confirmed in L. donovani promastigotes under different cell cycle phases, and it was shown to be secreted in the extracellular medium. Using an in vitro lipid binding assay, it was demonstrated that recombinant (r) LdSNXi (rGST-LdSNXi) tagged with glutathione-S-transferase (GST) binds to the PtdIns3P and PtdIns4P PIs. Using a specific a-LdSNXi antibody and immunofluorescence confocal microscopy, the intracellular localization of endogenous LdSNXi was analyzed in L. donovani promastigotes and axenic amastigotes. Additionally, rLdSNXi tagged with enhanced green fluorescent protein (rLdSNXi-EGFP) was heterologously expressed in transfected HeLa cells and its localization was examined. All observed localizations suggest functions compatible with the postulated SNX identity of LdSNXi. Sequence, structure, and evolutionary analysis revealed high homology between LdSNXi and the human SNX2, while the investigation of protein-protein interactions based on STRING (v.11.5) predicted putative molecular partners of LdSNXi in Leishmania.


Asunto(s)
Leishmania , Humanos , Leishmania/genética , Células HeLa , Nexinas de Clasificación/genética , Transducción de Señal , Anticuerpos , Glutatión Transferasa
4.
Mol Biol Cell ; 35(6): ar76, 2024 Jun 01.
Artículo en Inglés | MEDLINE | ID: mdl-38598303

RESUMEN

Endosomal coats incorporate membrane-binding subunits such as sorting nexin (SNX) proteins. The Saccharomyces cerevisiae SNX-BAR paralogs Vin1 and Vps5 are respective subunits of the endosomal VINE and retromer complexes whose dimerizing BAR domains are required for complex assembly and membrane association. However, a degree of promiscuity is predicted for yeast BAR-BAR pairings, and recent work has implicated the unstructured N-terminal domains of Vin1 and Vps5 in coat formation. Here, we map N-terminal signals in both SNX-BAR paralogs that contribute to the assembly and function of two distinct endosomal coats in vivo. Whereas Vin1 leverages a polybasic region and adjacent hydrophobic motif to bind Vrl1 and form VINE, the N-terminus of Vps5 interacts with the retromer subunit Vps29 at two sites, including a conserved hydrophobic pocket in Vps29 that engages other accessory proteins in humans. We also examined the sole isoform of Vps5 from the milk yeast Kluyveromyces lactis and found that ancestral yeasts may have used a nested N-terminal signal to form both VINE and retromer. Our results suggest that the specific assembly of Vps5-family SNX-BAR coats depends on inputs from unique N-terminal sequence features in addition to BAR domain coupling, expanding our understanding of endosomal coat biology.


Asunto(s)
Endosomas , Proteínas de Saccharomyces cerevisiae , Saccharomyces cerevisiae , Nexinas de Clasificación , Proteínas de Transporte Vesicular , Endosomas/metabolismo , Proteínas de Saccharomyces cerevisiae/metabolismo , Proteínas de Saccharomyces cerevisiae/genética , Nexinas de Clasificación/metabolismo , Nexinas de Clasificación/genética , Saccharomyces cerevisiae/metabolismo , Proteínas de Transporte Vesicular/metabolismo , Proteínas de Transporte Vesicular/genética , Unión Proteica , Dominios Proteicos , Humanos , Secuencia de Aminoácidos
5.
J Cell Sci ; 137(9)2024 May 01.
Artículo en Inglés | MEDLINE | ID: mdl-38606629

RESUMEN

The ADP-ribosylation factors (ARFs) and ARF-like (ARL) GTPases serve as essential molecular switches governing a wide array of cellular processes. In this study, we used proximity-dependent biotin identification (BioID) to comprehensively map the interactome of 28 out of 29 ARF and ARL proteins in two cellular models. Through this approach, we identified ∼3000 high-confidence proximal interactors, enabling us to assign subcellular localizations to the family members. Notably, we uncovered previously undefined localizations for ARL4D and ARL10. Clustering analyses further exposed the distinctiveness of the interactors identified with these two GTPases. We also reveal that the expression of the understudied member ARL14 is confined to the stomach and intestines. We identified phospholipase D1 (PLD1) and the ESCPE-1 complex, more precisely, SNX1, as proximity interactors. Functional assays demonstrated that ARL14 can activate PLD1 in cellulo and is involved in cargo trafficking via the ESCPE-1 complex. Overall, the BioID data generated in this study provide a valuable resource for dissecting the complexities of ARF and ARL spatial organization and signaling.


Asunto(s)
Factores de Ribosilacion-ADP , Fosfolipasa D , Transducción de Señal , Factores de Ribosilacion-ADP/metabolismo , Factores de Ribosilacion-ADP/genética , Humanos , Fosfolipasa D/metabolismo , Fosfolipasa D/genética , Células HEK293 , Animales , Nexinas de Clasificación/metabolismo , Nexinas de Clasificación/genética , Mapeo de Interacción de Proteínas
6.
JCI Insight ; 9(10)2024 Apr 16.
Artículo en Inglés | MEDLINE | ID: mdl-38625743

RESUMEN

Dysregulated lipid homeostasis is emerging as a potential cause of neurodegenerative disorders. However, evidence of errors in lipid homeostasis as a pathogenic mechanism of neurodegeneration remains limited. Here, we show that cerebellar neurodegeneration caused by Sorting Nexin 14 (SNX14) deficiency is associated with lipid homeostasis defects. Recent studies indicate that SNX14 is an interorganelle lipid transfer protein that regulates lipid transport, lipid droplet (LD) biogenesis, and fatty acid desaturation, suggesting that human SNX14 deficiency belongs to an expanding class of cerebellar neurodegenerative disorders caused by altered cellular lipid homeostasis. To test this hypothesis, we generated a mouse model that recapitulates human SNX14 deficiency at a genetic and phenotypic level. We demonstrate that cerebellar Purkinje cells (PCs) are selectively vulnerable to SNX14 deficiency while forebrain regions preserve their neuronal content. Ultrastructure and lipidomic studies reveal widespread lipid storage and metabolism defects in SNX14-deficient mice. However, predegenerating SNX14-deficient cerebella show a unique accumulation of acylcarnitines and depletion of triglycerides. Furthermore, defects in LD content and telolysosome enlargement in predegenerating PCs suggest lipotoxicity as a pathogenic mechanism of SNX14 deficiency. Our work shows a selective cerebellar vulnerability to altered lipid homeostasis and provides a mouse model for future therapeutic studies.


Asunto(s)
Homeostasis , Metabolismo de los Lípidos , Células de Purkinje , Nexinas de Clasificación , Nexinas de Clasificación/metabolismo , Nexinas de Clasificación/genética , Animales , Ratones , Humanos , Células de Purkinje/metabolismo , Células de Purkinje/patología , Modelos Animales de Enfermedad , Enfermedades Neurodegenerativas/metabolismo , Enfermedades Neurodegenerativas/patología , Enfermedades Neurodegenerativas/genética , Ratones Noqueados , Cerebelo/metabolismo , Cerebelo/patología , Masculino , Gotas Lipídicas/metabolismo
7.
Nat Commun ; 15(1): 2553, 2024 Mar 22.
Artículo en Inglés | MEDLINE | ID: mdl-38519472

RESUMEN

Lysosomal Storage Disorders (LSDs), which share common phenotypes, including enlarged lysosomes and defective lysosomal storage, are caused by mutations in lysosome-related genes. Although gene therapies and enzyme replacement therapies have been explored, there are currently no effective routine therapies against LSDs. During lysosome reformation, which occurs when the functional lysosome pool is reduced, lysosomal lipids and proteins are recycled to restore lysosome functions. Here we report that the sorting nexin protein SNX8 promotes lysosome tubulation, a process that is required for lysosome reformation, and that loss of SNX8 leads to phenotypes characteristic of LSDs in human cells. SNX8 overexpression rescued features of LSDs in cells, and AAV-based delivery of SNX8 to the brain rescued LSD phenotypes in mice. Importantly, by screening a natural compound library, we identified three small molecules that enhanced SNX8-lysosome binding and reversed LSD phenotypes in human cells and in mice. Altogether, our results provide a potential solution for the treatment of LSDs.


Asunto(s)
Enfermedades por Almacenamiento Lisosomal , Ratones , Animales , Humanos , Enfermedades por Almacenamiento Lisosomal/genética , Enfermedades por Almacenamiento Lisosomal/terapia , Enfermedades por Almacenamiento Lisosomal/metabolismo , Proteínas/metabolismo , Encéfalo/metabolismo , Mutación , Lisosomas/metabolismo , Nexinas de Clasificación/genética , Nexinas de Clasificación/metabolismo
8.
Anim Biotechnol ; 35(1): 2309956, 2024 Nov.
Artículo en Inglés | MEDLINE | ID: mdl-38315463

RESUMEN

SNX29 is a potential functional gene associated with meat production traits. Previous studies have shown that SNX29 copy number variation (CNV) could be implicated with phenotype in goats. However, in Diannan small-ear (DSE) pigs, the genetic impact of SNX29 CNV on growth traits remains unclear. Therefore, this study investigated the associations between SNX29 CNVs (CNV10810 and CNV10811) and growth traits in 415 DSE pigs. The results revealed that the CNV10810 mutation was significantly associated with backfat thickness in DSE pigs at 12 and 15 months old (P < 0.05), while the CNV10811 mutation had significant effects on various growth traits at 6 and 12 months old, particularly for body weight, body height, back height and backfat thickness (P < 0.05 or P < 0.001). In conclusion, our results confirm that SNX29 CNV plays a role in regulating growth and development in pigs, thus suggesting its potential application for pig breeding programmes.


Asunto(s)
Variaciones en el Número de Copia de ADN , Nexinas de Clasificación , Porcinos/genética , Animales , Variaciones en el Número de Copia de ADN/genética , Nexinas de Clasificación/genética , Fenotipo , Peso Corporal/genética , Dosificación de Gen
9.
Biochim Biophys Acta Biomembr ; 1866(4): 184305, 2024 Apr.
Artículo en Inglés | MEDLINE | ID: mdl-38408696

RESUMEN

The proteolipid code determines how cytosolic proteins find and remodel membrane surfaces. Here, we investigate how this process works with sorting nexins Snx1 and Snx3. Both proteins form sorting machines by recognizing membrane zones enriched in phosphatidylinositol 3-phosphate (PI3P), phosphatidylserine (PS) and cholesterol. This co-localized combination forms a unique "lipid codon" or lipidon that we propose is responsible for endosomal targeting, as revealed by structures and interactions of their PX domain-based readers. We outline a membrane recognition and remodeling mechanism for Snx1 and Snx3 involving this code element alongside transmembrane pH gradients, dipole moment-guided docking and specific protein-protein interactions. This generates an initial membrane-protein assembly (memtein) that then recruits retromer and additional PX proteins to recruit cell surface receptors for sorting to the trans-Golgi network (TGN), lysosome and plasma membranes. Post-translational modification (PTM) networks appear to regulate how the sorting machines form and operate at each level. The commonalities and differences between these sorting nexins show how the proteolipid code orchestrates parallel flows of molecular information from ribosome emergence to organelle genesis, and illuminates a universally applicable model of the membrane.


Asunto(s)
Proteínas Portadoras , Proteínas de Transporte Vesicular , Proteínas Portadoras/química , Proteínas de Transporte Vesicular/metabolismo , Nexinas de Clasificación/metabolismo , Transporte de Proteínas , Proteolípidos/metabolismo
10.
J Cell Biol ; 223(3)2024 03 04.
Artículo en Inglés | MEDLINE | ID: mdl-38323995

RESUMEN

In autophagy, autophagosomes deliver the lumenal contents to lysosomes for degradation via autophagosome-lysosome fusion. In contrast, autophagosome outer membrane components were recycled via autophagosomal components recycling (ACR), which is mediated by the recycler complex. The recycler complex, composed of SNX4, SNX5, and SNX17, cooperate with the dynein-dynactin complex to mediate ACR. However, how ACR is regulated remains unknown. Here, we found that Rab32 family proteins localize to autolysosomes and are required for ACR, rather than other autophagosomal or lysosomal Rab proteins. The GTPase activity of Rab32 family proteins, governed by their guanine nucleotide exchange factor and GTPase-activating protein, plays a key role in regulating ACR. This regulation occurs through the control of recycler complex formation, as well as the connection between the recycler-cargo and dynactin complex. Together, our study reveals an unidentified Rab32 family-dependent regulatory mechanism for ACR.


Asunto(s)
Autofagosomas , Dineínas , Proteínas Activadoras de GTPasa , Nexinas de Clasificación , Proteínas de Unión al GTP rab , Humanos , Citoesqueleto de Actina/metabolismo , Autofagosomas/metabolismo , Complejo Dinactina/metabolismo , Dineínas/metabolismo , Proteínas Activadoras de GTPasa/metabolismo , Lisosomas , Proteínas de Unión al GTP rab/metabolismo
11.
J Virol ; 98(1): e0159923, 2024 Jan 23.
Artículo en Inglés | MEDLINE | ID: mdl-38169281

RESUMEN

African swine fever virus (ASFV) causes a highly contagious and deadly disease in domestic pigs and European wild boars, posing a severe threat to the global pig industry. ASFV CP204L, a highly immunogenic protein, is produced during the early stages of ASFV infection. However, the impact of CP204L protein-interacting partners on the outcome of ASFV infection is poorly understood. To accomplish this, coimmunoprecipitation and mass spectrometry analysis were conducted in ASFV-infected porcine alveolar macrophages (PAMs). We have demonstrated that sorting nexin 32 (SNX32) is a CP204L-binding protein and that CP204L interacted and colocalized with SNX32 in ASFV-infected PAMs. ASFV growth and replication were promoted by silencing SNX32 and suppressed by overexpressing SNX32. SNX32 degraded CP204L by recruiting the autophagy-related protein Ras-related protein Rab-1b (RAB1B). RAB1B overexpression inhibited ASFV replication, while knockdown of RAB1B had the opposite effect. Additionally, RAB1B, SNX32, and CP204L formed a complex upon ASFV infection. Taken together, this study demonstrates that SNX32 antagonizes ASFV growth and replication by recruiting the autophagy-related protein RAB1B. This finding extends our understanding of the interaction between ASFV CP204L and its host and provides new insights into exploring the relationship between ASFV infection and autophagy.IMPORTANCEAfrican swine fever (ASF) is a highly contagious and acute hemorrhagic viral disease with a high mortality near 100% in domestic pigs. ASF virus (ASFV), which is the only member of the family Asfarviridae, is a dsDNA virus of great complexity and size, encoding more than 150 proteins. Currently, there are no available vaccines against ASFV. ASFV CP204L represents the most abundantly expressed viral protein early in infection and plays an important role in regulating ASFV replication. However, the mechanism by which the interaction between ASFV CP204L and host proteins affects ASFV replication remains unclear. In this study, we demonstrated that the cellular protein SNX32 interacted with CP204L and degraded CP204L by upregulating the autophagy-related protein RAB1B. In summary, this study will help us understand the interaction mechanism between CP204L and its host upon infection and provide new insights for the development of vaccines and antiviral drugs.


Asunto(s)
Virus de la Fiebre Porcina Africana , Fiebre Porcina Africana , Factores de Restricción Antivirales , Autofagia , Nexinas de Clasificación , Proteínas de Unión al GTP rab1 , Animales , Proteínas Relacionadas con la Autofagia/metabolismo , Sus scrofa/virología , Porcinos/virología , Nexinas de Clasificación/metabolismo , Factores de Restricción Antivirales/metabolismo , Proteínas de Unión al GTP rab1/metabolismo , Macrófagos/virología , Replicación Viral
12.
Eur J Cell Biol ; 103(1): 151381, 2024 Mar.
Artículo en Inglés | MEDLINE | ID: mdl-38183814

RESUMEN

The facultative intracellular pathogen Shigella flexneri invades non-phagocytic epithelial gut cells. Through a syringe-like apparatus called type 3 secretion system, it injects effector proteins into the host cell triggering actin rearrangements leading to its uptake within a tight vacuole, termed the bacterial-containing vacuole (BCV). Simultaneously, Shigella induces the formation of large vesicles around the entry site, which we refer to as infection-associated macropinosomes (IAMs). After entry, Shigella ruptures the BCV and escapes into the host cytosol by disassembling the BCV remnants. Previously, IAM formation has been shown to be required for efficient BCV escape, but the molecular events associated with BCV disassembly have remained unclear. To identify host components required for BCV disassembly, we performed a microscopy-based screen to monitor the recruitment of BAR domain-containing proteins, which are a family of host proteins involved in membrane shaping and sensing (e.g. endocytosis and recycling) during Shigella epithelial cell invasion. We identified endosomal recycling BAR protein Sorting Nexin-8 (SNX8) localized to IAMs in a PI(3)P-dependent manner before BCV disassembly. At least two distinct IAM subpopulations around the BCV were found, either being recycled back to cellular compartments such as the plasma membrane or transitioning to become RAB11A positive "contact-IAMs" involved in promoting BCV rupture. The IAM subpopulation duality was marked by the exclusive recruitment of either SNX8 or RAB11A. Hindering PI(3)P production at the IAMs led to an inhibition of SNX8 recruitment at these compartments and delayed both, the step of BCV rupture time and successful BCV disassembly. Finally, siRNA depletion of SNX8 accelerated BCV rupture and unpeeling of BCV remnants, indicating that SNX8 is involved in controlling the timing of the cytosolic release. Overall, our work sheds light on how Shigella establishes its intracellular niche through the subversion of a specific set of IAMs.


Asunto(s)
Fosfatos de Fosfatidilinositol , Shigella , Humanos , Shigella/fisiología , Vacuolas/metabolismo , Células Epiteliales/fisiología , Shigella flexneri/genética , Células HeLa , Nexinas de Clasificación/metabolismo
13.
Mol Immunol ; 166: 79-86, 2024 Feb.
Artículo en Inglés | MEDLINE | ID: mdl-38271879

RESUMEN

BACKGROUND: Liver ischemia reperfusion (IR) injury is a common cause of liver dysfunction in patients post liver partial resection and liver transplantation. However, the cellular defense mechanisms underlying IR are not well understood. Macrophage mediated sterile inflammation plays critical roles in liver IR injury. Sorting nexin (SNX) 10, a member of the SNX family which functions in regulation of endosomal sorting. This study aimed to explore the role of sorting nexin 10 (SNX10) during liver IR injury with a focus on regulating macrophage function. METHODS: Both the gene and protein expression levels of SNX10 were analyzed in human specimens from 10 patients undergoing liver partial resection with ischemic insult and in a mouse model of liver IR. The in vivo effects of SNX10 in liver IR injury and sterile inflammation in mice were investigated. Bone marrow derived macrophages (BMDMs) were used to determine the role of SNX10 in modulating macrophage function in vitro. RESULTS: Increased expression of SNX10 was observed both in human specimens and mice livers post IR. SNX10 knockdown alleviated IR induced sterile inflammation and liver damage in mice. SNX10 promoted M1 polarization of macrophage treated with LPS and facilitated inflammatory response by activating NLRP3 inflammasome. CONCLUSIONS: We report for the first time that SNX10 is upregulated in IR-stressed livers. SNX10 activation aggravates liver IR injury and sterile inflammation by facilitating macrophage M1 polarization and inflammatory response suggesting SNX10 as a potential therapeutic target for liver IR injury.


Asunto(s)
Inflamasomas , Daño por Reperfusión , Humanos , Animales , Ratones , Inflamasomas/metabolismo , Proteína con Dominio Pirina 3 de la Familia NLR/metabolismo , Nexinas de Clasificación/genética , Nexinas de Clasificación/metabolismo , Hígado/metabolismo , Macrófagos/metabolismo , Inflamación/metabolismo , Daño por Reperfusión/metabolismo
14.
Mol Neurobiol ; 61(3): 1346-1362, 2024 Mar.
Artículo en Inglés | MEDLINE | ID: mdl-37704928

RESUMEN

Sorting nexin17 (SNX17) is a member of the sorting nexin family, which plays a crucial role in endosomal trafficking. Previous research has shown that SNX17 is involved in the recycling or degradation of various proteins associated with neurodevelopmental and neurological diseases in cell models. However, the significance of SNX17 in neurological function in the mouse brain has not been thoroughly investigated. In this study, we generated Snx17 knockout mice and observed that the homozygous deletion of Snx17 (Snx17-/-) resulted in lethality. On the other hand, heterozygous mutant mice (Snx17+/-) exhibited anxiety-like behavior with a reduced preference for social novelty. Furthermore, Snx17 haploinsufficiency led to impaired synaptic transmission and reduced maturation of dendritic spines. Through GST pulldown and interactome analysis, we identified the SRC kinase inhibitor, p140Cap, as a potential downstream target of SNX17. We also demonstrated that the interaction between p140Cap and SNX17 is crucial for dendritic spine maturation. Together, this study provides the first in vivo evidence highlighting the important role of SNX17 in maintaining neuronal function, as well as regulating social novelty and anxiety-like behaviors.


Asunto(s)
Espinas Dendríticas , Nexinas de Clasificación , Animales , Ratones , Espinas Dendríticas/metabolismo , Homocigoto , Transporte de Proteínas , Eliminación de Secuencia , Nexinas de Clasificación/genética , Nexinas de Clasificación/metabolismo
15.
Chem Biol Drug Des ; 103(1): e14405, 2024 01.
Artículo en Inglés | MEDLINE | ID: mdl-37989501

RESUMEN

Gastric cancer currently has no effective treatment due to its high metastasis and heterogeneity. It has been reported that ropivacaine (Rop) can inhibit the growth, migration, and invasion of gastric cancer. However, the therapeutic mechanism of Rop still needs to be further explored to provide insights for its clinical application. This study aimed to explore the effects of Rop on the growth, migration, and invasion of gastric cancer cells and the underlying mechanisms. The expression levels of SNX10 were assessed in gastric cancer tissues and cell line AGS by qRT-PCR. Cell Counting Kit-8 (CCK8) assay, wound-healing assay, and transwell assay were then used to examine the effects of Rop on the AGS cell viability, migration, invasion, and proliferation, respectively. Additionally, colony formation assay was used to measure cell proliferation ability, and flow cytometry was used to detect apoptosis level. Protein levels of SNX10, SRC, and STAT3 were detected by western blot. According to the experimental results, the decreased SNX10 mRNA expression was observed in gastric cancer tissue and cell line AGS. Rop inhibited the proliferation, migration, and invasion of AGS cells, but promoted apoptosis and upregulated SNX10 expression. Moreover, Rop inhibited the expression of MMP-2 and MMP-9, phosphorylation of SRC and STAT3. SNX10 knockdown could reverse Rop-induced anticancer effects. Collectively, Rop showed a potential role in preventing proliferation and metastasis of gastric cancer. The action mechanism of Rop may be related to the upregulation of SNX10 expression and further inhibition of SRC/STAT3 signaling pathway. Our findings provide new insights into the anticancer properties of Rop.


Asunto(s)
Neoplasias Gástricas , Humanos , Neoplasias Gástricas/tratamiento farmacológico , Ropivacaína/farmacología , Ropivacaína/uso terapéutico , Movimiento Celular , Transducción de Señal , Proliferación Celular , Línea Celular Tumoral , Apoptosis , Regulación Neoplásica de la Expresión Génica , Factor de Transcripción STAT3/genética , Factor de Transcripción STAT3/metabolismo , Nexinas de Clasificación/genética , Nexinas de Clasificación/metabolismo
16.
Sci Adv ; 9(35): eadh5016, 2023 09.
Artículo en Inglés | MEDLINE | ID: mdl-37647408

RESUMEN

Intestinal stem cell (ISC) is a promising therapeutic target for inflammatory bowel disease. Cholesterol availability is critical for ISC stemness. Low plasma cholesterol is a typical feature of Crohn's disease (CD); however, its impact on mucosal healing remains unclear. Here, we identified an essential role of sorting nexin 10 (SNX10) in maintaining the stemness of ISCs. SNX10 expression in intestinal tissues positively correlates with the severity of human CD and mouse colitis. Conditional SNX10 knockout in intestinal epithelial cells or ISCs promotes intestinal mucosal repair by maintaining the ISC population associated with increased intracellular cholesterol synthesis. Disassociation of ERLIN2 with SCAP by SNX10 deletion enhances the activation of SREBP2, resulting in increased cholesterol biosynthesis. DC-SX029, a small-molecule inhibitor of SNX10, was used to verify the druggable potential of SNX10 for the treatment of patients with CD. Our study provides a strategy for mucosal healing through SREBP2-mediated stemness restoration of ISCs.


Asunto(s)
Enfermedades Inflamatorias del Intestino , Nexinas de Clasificación , Animales , Humanos , Ratones , Mucosa Intestinal , Intestinos , Nexinas de Clasificación/genética , Células Madre
17.
Plant Cell ; 35(12): 4217-4237, 2023 Nov 30.
Artículo en Inglés | MEDLINE | ID: mdl-37647529

RESUMEN

Membrane protein homeostasis is fine-tuned by the cellular pathways for vacuolar degradation and recycling, which ultimately facilitate plant growth and cell-environment interactions. The endosomal sorting complex required for transport (ESCRT) machinery plays important roles in regulating intraluminal vesicle (ILV) formation and membrane protein sorting to vacuoles. We previously showed that the plant-specific ESCRT component FYVE DOMAIN PROTEIN REQUIRED FOR ENDOSOMAL SORTING1 (FREE1) performs multiple functions in plants, although the underlying mechanisms remain elusive. In this study, we performed a suppressor screen of the FREE1-RNAi mutant and identified and characterized 2 suppressor of free1 (sof) mutants in Arabidopsis (Arabidopsis thaliana). These mutants, sof10 and sof641, result in a premature stop codon or a missense mutation in AT5G10370, respectively. This gene was named DEAH and RING domain-containing protein as FREE1 suppressor 1 (DRIF1). DRIF1 has a homologous gene, DRIF2, in the Arabidopsis genome with 95% identity to DRIF1. The embryos of drif1 drif2 mutants arrested at the globular stage and formed enlarged multivesicular bodies (MVBs) with an increased number of ILVs. DRIF1 is a membrane-associated protein that coordinates with retromer component sorting nexin 1 to regulate PIN-FORMED2 recycling to the plasma membrane. Altogether, our data demonstrate that DRIF1 is a unique retromer interactor that orchestrates FREE1-mediated ILV formation of MVBs and vacuolar sorting of membrane proteins for degradation in plants.


Asunto(s)
Proteínas de Arabidopsis , Arabidopsis , Arabidopsis/metabolismo , Nexinas de Clasificación/genética , Nexinas de Clasificación/metabolismo , Proteínas de Arabidopsis/metabolismo , Proteínas de Plantas/metabolismo , Complejos de Clasificación Endosomal Requeridos para el Transporte/metabolismo , Proteostasis , Transporte de Proteínas/genética , Plantas/metabolismo , Proteínas de Transporte Vesicular/genética , Proteínas de Transporte Vesicular/metabolismo
19.
Mol Biol Cell ; 34(9): ar87, 2023 08 01.
Artículo en Inglés | MEDLINE | ID: mdl-37314856

RESUMEN

Proper balance of exocytosis and endocytosis is important for the maintenance of plasma membrane lipid and protein homeostasis. This is especially critical in human podocytes and the podocyte-like Drosophila nephrocytes that both use a delicate diaphragm system with evolutionarily conserved components for ultrafiltration. Here, we show that the sorting nexin 25 homologue Snazarus (Snz) binds to Rab11 and localizes to Rab11-positive recycling endosomes in Drosophila nephrocytes, unlike in fat cells where it is present in plasma membrane/lipid droplet/endoplasmic reticulum contact sites. Loss of Snz leads to redistribution of Rab11 vesicles from the cell periphery and increases endocytic activity in nephrocytes. These changes are accompanied by defects in diaphragm protein distribution that resemble those seen in Rab11 gain-of-function cells. Of note, co-overexpression of Snz rescues diaphragm defects in Rab11 overexpressing cells, whereas snz knockdown in Rab11 overexpressing nephrocytes or simultaneous knockdown of snz and tbc1d8b encoding a Rab11 GTPase-activating protein (GAP) leads to massive expansion of the lacunar system that contains mislocalized diaphragm components: Sns and Pyd/ZO-1. We find that loss of Snz enhances while its overexpression impairs secretion, which, together with genetic epistasis analyses, suggest that Snz counteracts Rab11 to maintain the diaphragm via setting the proper balance of exocytosis and endocytosis.


Asunto(s)
Proteínas de Drosophila , Animales , Humanos , Proteínas de Drosophila/metabolismo , Nexinas de Clasificación/metabolismo , Diafragma/metabolismo , Ultrafiltración , Drosophila/metabolismo , Proteínas de Unión al GTP rab/metabolismo , Endocitosis , Endosomas/metabolismo
20.
Elife ; 122023 05 09.
Artículo en Inglés | MEDLINE | ID: mdl-37158588

RESUMEN

Sorting nexins (SNX) are a family of proteins containing the Phox homology domain, which shows a preferential endo-membrane association and regulates cargo sorting processes. Here, we established that SNX32, an SNX-BAR (Bin/Amphiphysin/Rvs) sub-family member associates with SNX4 via its BAR domain and the residues A226, Q259, E256, R366 of SNX32, and Y258, S448 of SNX4 that lie at the interface of these two SNX proteins mediate this association. SNX32, via its PX domain, interacts with the transferrin receptor (TfR) and Cation-Independent Mannose-6-Phosphate Receptor (CIMPR), and the conserved F131 in its PX domain is important in stabilizing these interactions. Silencing of SNX32 leads to a defect in intracellular trafficking of TfR and CIMPR. Further, using SILAC-based differential proteomics of the wild-type and the mutant SNX32, impaired in cargo binding, we identified Basigin (BSG), an immunoglobulin superfamily member, as a potential interactor of SNX32 in SHSY5Y cells. We then demonstrated that SNX32 binds to BSG through its PX domain and facilitates its trafficking to the cell surface. In neuroglial cell lines, silencing of SNX32 leads to defects in neuronal differentiation. Moreover, abrogation in lactate transport in the SNX32-depleted cells led us to propose that SNX32 may contribute to maintaining the neuroglial coordination via its role in BSG trafficking and the associated monocarboxylate transporter activity. Taken together, our study showed that SNX32 mediates the trafficking of specific cargo molecules along distinct pathways.


Asunto(s)
Endosomas , Proyección Neuronal , Endosomas/metabolismo , Transporte de Proteínas , Membrana Celular/metabolismo , Nexinas de Clasificación/metabolismo
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