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Non-coding RNAs (ncRNAs) are a heterogeneous group, in terms of structure and sequence length, consisting of RNA molecules that do not code for proteins. These ncRNAs have a central role in the regulation of gene expression and are virtually involved in every process analyzed, ensuring cellular homeostasis. Although, over the years, much research has focused on the characterization of non-coding transcripts of nuclear origin, improved bioinformatic tools and next-generation sequencing (NGS) platforms have allowed the identification of hundreds of ncRNAs transcribed from the mitochondrial genome (mt-ncRNA), including long non-coding RNA (lncRNA), circular RNA (circRNA), and microRNA (miR). Mt-ncRNAs have been described in diverse cellular processes such as mitochondrial proteome homeostasis and retrograde signaling; however, the function of the majority of mt-ncRNAs remains unknown. This review focuses on a subgroup of human mt-ncRNAs whose dysfunction is associated with both failures in cell cycle regulation, leading to defects in cell growth, cell proliferation, and apoptosis, and the development of tumor hallmarks, such as cell migration and metastasis formation, thus contributing to carcinogenesis and tumor development. Here we provide an overview of the mt-ncRNAs/cancer relationship that could help the future development of new biomedical applications in the field of oncology.
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Neoplasias , RNA não Traduzido , Humanos , Neoplasias/genética , Neoplasias/patologia , Neoplasias/metabolismo , RNA não Traduzido/genética , RNA não Traduzido/metabolismo , Divisão Celular/genética , Animais , Mitocôndrias/metabolismo , Mitocôndrias/genética , Regulação Neoplásica da Expressão Gênica , RNA Circular/genética , RNA Circular/metabolismo , Genoma Mitocondrial , RNA Longo não Codificante/genética , RNA Longo não Codificante/metabolismo , MicroRNAs/genética , MicroRNAs/metabolismoRESUMO
Infective endocarditis (IE) on atrial septal defect (ASD) closure devices, while extremely rare, has been reported to be more frequent early after the procedure. We describe a case of late IE after percutaneous closure of patent foramen ovale (PFO). We also performed a literature review on this subject. We reviewed a total of 42,365 patients who were treated with percutaneous devices: 13,916 for ostium secundum (OS) (32%), 24,726 for PFO (58%) and 3,723 for OS+PFO (8%). Among these patients, we identified 50 cases of IE after atrial septal defect device closure (0.001%). In contrast to previous reports, nearly 66% of IE in this setting occurred late, after at least 6 months from the procedure (33/50 patients). A statistical analysis clearly showed that the mean time from the procedure to IE increased in the last five years, probably associated with a change in antiplatelet therapy after ASD closure. Management of IE on an ASD occluder should always be discussed in the setting of a multidisciplinary heart team that includes a cardiologist, cardiac surgeon, and anesthetist. While surgical strategies gave excellent results, conservative management might be considered in cases of small IE vegetations and for patients in good general condition. However, in these cases, the patient must be closely observed with repeated blood and instrumental tests.
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In animal cell cytokinesis, interaction of non-muscle myosin II (NMII) with F-actin provides the dominant force for pinching the mother cell into two daughters. Here we demonstrate that celibe (cbe) is a missense allele of zipper, which encodes the Drosophila Myosin heavy chain. Mutation of cbe impairs binding of Zipper protein to the regulatory light chain Spaghetti squash (Sqh). In dividing spermatocytes from cbe males, Sqh fails to concentrate at the equatorial cortex, resulting in thin actomyosin rings that are unable to constrict. We show that cbe mutation impairs localization of the phosphatidylinositol 4-phosphate [PI(4)P]-binding protein Golgi phosphoprotein 3 (GOLPH3, also known as Sauron) and maintenance of centralspindlin at the cell equator of telophase cells. Our results further demonstrate that GOLPH3 protein associates with Sqh and directly binds the centralspindlin subunit Pavarotti. We propose that during cytokinesis, the reciprocal dependence between Myosin and PI(4)P-GOLPH3 regulates centralspindlin stabilization at the invaginating plasma membrane and contractile ring assembly.
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Citocinese , Proteínas de Drosophila , Miosina Tipo II , Proteínas Oncogênicas , Actinas , Animais , Citocinese/genética , Drosophila , Proteínas de Drosophila/genética , Masculino , Miosina Tipo II/genéticaRESUMO
During the extended prophase of Drosophila gametogenesis, spermatocytes undergo robust gene transcription and store many transcripts in the cytoplasm in a repressed state, until translational activation of select mRNAs in later steps of spermatogenesis. Here, we characterize the Drosophila Doublefault (Dbf) protein as a C2H2 zinc-finger protein, primarily expressed in testes, that is required for normal meiotic division and spermiogenesis. Loss of Dbf causes premature centriole disengagement and affects spindle structure, chromosome segregation and cytokinesis. We show that Dbf interacts with the RNA-binding protein Syncrip/hnRNPQ, a key regulator of localized translation in Drosophila We propose that the pleiotropic effects of dbf loss-of-function mutants are associated with the requirement of dbf function for translation of specific transcripts in spermatocytes. In agreement with this hypothesis, Dbf protein binds cyclin B mRNA and is essential for translation of cyclin B in mature spermatocytes.
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Proteínas de Drosophila/fisiologia , Drosophila melanogaster/embriologia , Regulação da Expressão Gênica no Desenvolvimento , Peptídeos e Proteínas de Sinalização Intracelular/fisiologia , Meiose , RNA Mensageiro/genética , Espermatogênese , Animais , Axonema/metabolismo , Núcleo Celular/metabolismo , Centrossomo/metabolismo , Segregação de Cromossomos , Clonagem Molecular , Cruzamentos Genéticos , Ciclina B , Citocinese , Proteínas de Drosophila/genética , Hibridização in Situ Fluorescente , Peptídeos e Proteínas de Sinalização Intracelular/genética , Masculino , Microtúbulos/metabolismo , Mutação , Proteínas de Ligação a RNA , Espermatócitos/metabolismo , Fuso Acromático/metabolismo , Transgenes , Dedos de ZincoRESUMO
Golgi phosphoprotein 3 (GOLPH3), a Phosphatidylinositol 4-Phosphate [PI(4)P] effector at the Golgi, is required for Golgi ribbon structure maintenance, vesicle trafficking and Golgi glycosylation. GOLPH3 has been validated as an oncoprotein through combining integrative genomics with clinopathological and functional analyses. It is frequently amplified in several solid tumor types including melanoma, lung cancer, breast cancer, glioma, and colorectal cancer. Overexpression of GOLPH3 correlates with poor prognosis in multiple tumor types including 52% of breast cancers and 41% to 53% of glioblastoma. Roles of GOLPH3 in tumorigenesis may correlate with several cellular activities including: (i) regulating Golgi-to-plasma membrane trafficking and contributing to malignant secretory phenotypes; (ii) controlling the internalization and recycling of key signaling molecules or increasing the glycosylation of cancer relevant glycoproteins; and (iii) influencing the DNA damage response and maintenance of genomic stability. Here we summarize current knowledge on the oncogenic pathways involving GOLPH3 in human cancer, GOLPH3 influence on tumor metabolism and surrounding stroma, and its possible role in tumor metastasis formation.
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Proteínas de Membrana/genética , Proteínas de Membrana/metabolismo , Neoplasias/metabolismo , Amplificação de Genes , Regulação Neoplásica da Expressão Gênica , Complexo de Golgi/metabolismo , Humanos , Neoplasias/genética , Prognóstico , Regulação para CimaRESUMO
Congenital disorders of glycosylation (CDG) comprise a family of human multisystemic diseases caused by recessive mutations in genes required for protein N-glycosylation. More than 100 distinct forms of CDGs have been identified and most of them cause severe neurological impairment. The Conserved Oligomeric Golgi (COG) complex mediates tethering of vesicles carrying glycosylation enzymes across the Golgi cisternae. Mutations affecting human COG1, COG2 and COG4-COG8 cause monogenic forms of inherited, autosomal recessive CDGs. We have generated a Drosophila COG7-CDG model that closely parallels the pathological characteristics of COG7-CDG patients, including pronounced neuromotor defects associated with altered N-glycome profiles. Consistent with these alterations, larval neuromuscular junctions of Cog7 mutants exhibit a significant reduction in bouton numbers. We demonstrate that the COG complex cooperates with Rab1 and Golgi phosphoprotein 3 to regulate Golgi trafficking and that overexpression of Rab1 can rescue the cytokinesis and locomotor defects associated with loss of Cog7. Our results suggest that the Drosophila COG7-CDG model can be used to test novel potential therapeutic strategies by modulating trafficking pathways.
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Defeitos Congênitos da Glicosilação/genética , Proteínas de Drosophila/genética , Drosophila melanogaster/genética , Transtornos Neurológicos da Marcha/genética , Proteínas Oncogênicas/genética , Processamento de Proteína Pós-Traducional , Proteínas de Transporte Vesicular/genética , Animais , Transporte Biológico , Defeitos Congênitos da Glicosilação/metabolismo , Defeitos Congênitos da Glicosilação/patologia , Modelos Animais de Doenças , Proteínas de Drosophila/deficiência , Proteínas de Drosophila/metabolismo , Drosophila melanogaster/crescimento & desenvolvimento , Drosophila melanogaster/metabolismo , Transtornos Neurológicos da Marcha/metabolismo , Transtornos Neurológicos da Marcha/patologia , Deleção de Genes , Regulação da Expressão Gênica no Desenvolvimento , Teste de Complementação Genética , Glicosilação , Complexo de Golgi/metabolismo , Complexo de Golgi/patologia , Humanos , Larva/genética , Larva/crescimento & desenvolvimento , Larva/metabolismo , Manose/metabolismo , Junção Neuromuscular/metabolismo , Junção Neuromuscular/patologia , Proteínas Oncogênicas/metabolismo , Fenótipo , Polissacarídeos/metabolismo , Proteínas de Transporte Vesicular/deficiência , Proteínas rab de Ligação ao GTP/genética , Proteínas rab de Ligação ao GTP/metabolismoRESUMO
Mitotic and cytokinetic processes harness cell machinery to drive chromosomal segregation and the physical separation of dividing cells. Here, we investigate the functional requirements for exocyst complex function during cell division in vivo, and demonstrate a common mechanism that directs anaphase cell elongation and cleavage furrow progression during cell division. We show that onion rings (onr) and funnel cakes (fun) encode the Drosophila homologs of the Exo84 and Sec8 exocyst subunits, respectively. In onr and fun mutant cells, contractile ring proteins are recruited to the equatorial region of dividing spermatocytes. However, cytokinesis is disrupted early in furrow ingression, leading to cytokinesis failure. We use high temporal and spatial resolution confocal imaging with automated computational analysis to quantitatively compare wild-type versus onr and fun mutant cells. These results demonstrate that anaphase cell elongation is grossly disrupted in cells that are compromised in exocyst complex function. Additionally, we observe that the increase in cell surface area in wild type peaks a few minutes into cytokinesis, and that onr and fun mutant cells have a greatly reduced rate of surface area growth specifically during cell division. Analysis by transmission electron microscopy reveals a massive build-up of cytoplasmic astral membrane and loss of normal Golgi architecture in onr and fun spermatocytes, suggesting that exocyst complex is required for proper vesicular trafficking through these compartments. Moreover, recruitment of the small GTPase Rab11 and the PITP Giotto to the cleavage site depends on wild-type function of the exocyst subunits Exo84 and Sec8. Finally, we show that the exocyst subunit Sec5 coimmunoprecipitates with Rab11. Our results are consistent with the exocyst complex mediating an essential, coordinated increase in cell surface area that potentiates anaphase cell elongation and cleavage furrow ingression.
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Anáfase , Ciclo Celular , Drosophila/citologia , AnimaisRESUMO
The highly conserved Golgi phosphoprotein 3 (GOLPH3) protein has been described as a Phosphatidylinositol 4-phosphate [PI(4)P] effector at the Golgi. GOLPH3 is also known as a potent oncogene, commonly amplified in several human tumors. However, the molecular pathways through which the oncoprotein GOLPH3 acts in malignant transformation are largely unknown. GOLPH3 has never been involved in cytokinesis. Here, we characterize the Drosophila melanogaster homologue of human GOLPH3 during cell division. We show that GOLPH3 accumulates at the cleavage furrow and is required for successful cytokinesis in Drosophila spermatocytes and larval neuroblasts. In premeiotic spermatocytes GOLPH3 protein is required for maintaining the organization of Golgi stacks. In dividing spermatocytes GOLPH3 is essential for both contractile ring and central spindle formation during cytokinesis. Wild type function of GOLPH3 enables maintenance of centralspindlin and Rho1 at cell equator and stabilization of Myosin II and Septin rings. We demonstrate that the molecular mechanism underlying GOLPH3 function in cytokinesis is strictly dependent on the ability of this protein to interact with PI(4)P. Mutations that abolish PI(4)P binding impair recruitment of GOLPH3 to both the Golgi and the cleavage furrow. Moreover telophase cells from mutants with defective GOLPH3-PI(4)P interaction fail to accumulate PI(4)P-and Rab11-associated secretory organelles at the cleavage site. Finally, we show that GOLPH3 protein interacts with components of both cytokinesis and membrane trafficking machineries in Drosophila cells. Based on these results we propose that GOLPH3 acts as a key molecule to coordinate phosphoinositide signaling with actomyosin dynamics and vesicle trafficking during cytokinesis. Because cytokinesis failures have been associated with premalignant disease and cancer, our studies suggest novel insight into molecular circuits involving the oncogene GOLPH3 in cytokinesis.
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Citocinese , Proteínas de Drosophila/fisiologia , Drosophila melanogaster/citologia , Proteínas rab de Ligação ao GTP/metabolismo , Sequência de Aminoácidos , Animais , Sítios de Ligação , Proteínas de Drosophila/química , Proteínas de Drosophila/genética , Proteínas de Drosophila/metabolismo , Humanos , Dados de Sequência Molecular , Mutação , Homologia de Sequência de Aminoácidos , Fuso AcromáticoRESUMO
Cytokinesis is an intricate process that requires an intimate interplay between actomyosin ring constriction and plasma membrane remodelling at the cleavage furrow. However, the molecular mechanisms involved in coupling the cytoskeleton dynamics with vesicle trafficking during cytokinesis are poorly understood. The highly conserved Golgi phosphoprotein 3 (GOLPH3), functions as a phosphatidylinositol 4-phosphate (PI4P) effector at the Golgi. Recent studies have suggested that GOLPH3 is up-regulated in several cancers and is associated with poor prognosis and more aggressive tumours. In Drosophila melanogaster, GOLPH3 localizes at the cleavage furrow of dividing cells, is required for successful cytokinesis and acts as a key molecule in coupling phosphoinositide (PI) signalling with actomyosin ring dynamics. Because cytokinesis failures have been linked with pre-malignant disease and cancer, the novel connection between GOLPH3 and cytokinesis imposes new fields of investigation in cancer biology and therapy.
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Membrana Celular/metabolismo , Citocinese , Proteínas de Membrana/fisiologia , Sequência de Aminoácidos , Animais , Complexo de Golgi/metabolismo , Humanos , Dados de Sequência Molecular , Transporte ProteicoRESUMO
The conserved oligomeric Golgi (COG) complex plays essential roles in Golgi function, vesicle trafficking and glycosylation. Deletions in the human COG7 gene are associated with a rare multisystemic congenital disorder of glycosylation that causes mortality within the first year of life. In this paper, we characterise the Drosophila orthologue of COG7 (Cog7). Loss-of-function Cog7 mutants are viable but male sterile. The Cog7 gene product is enriched in the Golgi stacks and in Golgi-derived structures throughout spermatogenesis. Mutations in the Cog7 gene disrupt Golgi architecture and reduce the number of Golgi stacks in primary spermatocytes. During spermiogenesis, loss of the Cog7 protein impairs the assembly of the Golgi-derived acroblast in spermatids and affects axoneme architecture. Similar to the Cog5 homologue, four way stop (Fws), Cog7 enables furrow ingression during cytokinesis. We show that the recruitment of the small GTPase Rab11 and the phosphatidylinositol transfer protein Giotto (Gio) to the cleavage site requires a functioning wild-type Cog7 gene. In addition, Gio coimmunoprecipitates with Cog7 and with Rab11 in the testes. Our results altogether implicate Cog7 as an upstream component in a gio-Rab11 pathway controlling membrane addition during cytokinesis.
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Citocinese/genética , Proteínas de Drosophila/genética , Drosophila melanogaster/citologia , Complexo de Golgi/metabolismo , Meiose/genética , Espermatogênese , Espermatozoides/citologia , Proteínas de Transporte Vesicular/genética , Sequência de Aminoácidos , Animais , Axonema/metabolismo , Axonema/ultraestrutura , Proteínas de Drosophila/química , Proteínas de Drosophila/metabolismo , Drosophila melanogaster/genética , Drosophila melanogaster/ultraestrutura , Genes de Insetos/genética , Glicoconjugados/metabolismo , Complexo de Golgi/ultraestrutura , Humanos , Larva/citologia , Larva/metabolismo , Larva/ultraestrutura , Masculino , Dados de Sequência Molecular , Mutação/genética , Espermátides/citologia , Espermátides/crescimento & desenvolvimento , Espermátides/ultraestrutura , Espermatócitos/citologia , Espermatócitos/metabolismo , Espermatócitos/ultraestrutura , Espermatozoides/metabolismo , Proteínas de Transporte Vesicular/química , Proteínas de Transporte Vesicular/metabolismoRESUMO
Background: The inhibition of PCSK9 lowered LDL cholesterol levels, reducing the risk of cardiovascular events. However, the effect on patients who have undergone surgical myocardial revascularization has not yet been evaluated. Methods: From January 2017 to December 2022, 180 dyslipidemic patients who underwent coronary artery bypass were included in the study. Until December 2019, 100 patients optimized therapy with statin ± ezetimibe (SG). Since January 2020, 80 matched patients added treatment with Evolocumab every 2 weeks (EG). All 180 patients were followed-up at 3 and 12 months, comparing outcomes. Results: The two groups are homogenous. At 3 months and 1 year, a significant decrease in the parameter mean levels of LDL cholesterol and total cholesterol is detected in the Evolocumab group compared to the standard group. No mortality was detected in either group. No complications or drug discontinuation were recorded. In the SG group, five patients (5%) suffered a myocardial infarction during the 1-year follow-up. In the EG group, two patients (2.5%) underwent PTCA due to myocardial infarction. There is no significant difference in overall survival according to the new treatment (p-value = 0.9), and the hazard ratio is equal to 0.94 (95% C.I.: [0.16-5.43]; p-value = 0.9397). Conclusions: The use of Evolocumab, which was started immediately after coronary artery bypass graft surgery, significantly reduced LDL cholesterol and total cholesterol levels compared to statin treatment alone and is completely safe. However, at one year of follow-up, this result did not have impact on the reduction in major clinical events.
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OBJECTIVE: Transcatheter aortic valve implant (TAVI) is the gold standard for the high-surgical-risk group of patients with aortic valve disease and it is an alternative to surgery in patients at intermediate risk. Lethal complications can occur, and many of these are manageable only with emergent conversion to open heart surgery. We retrospectively evaluate the outcome of all patients undergoing TAVI in our departments and the impact of a complete cardiac rescue team to reduce 30-day mortality. METHODS: Data from all patients undergoing TAVI between January 2020 and August 2023 in our center were analyzed. An expert complete rescue was present in catheter laboratory. Primary outcomes were in-hospital and at 30-day mortality and evaluation of all cases needed for emergent conversion to open heart surgery. RESULTS: 825 patients were enrolled. The total mortality was 19/825 (2.3%). Eleven of the total patients (1.3%) required emergent conversion to open heart surgery. Among them, eight were alive (73%), with a theoretical decrease of 0.98% in overall mortality. CONCLUSIONS: surgical treatment is rare during TAVI. The presence of an expert complete rescue team as support means an increase in survival. Surgery must be used only to restore circulatory and to treat complication while percutaneous approaches should complete the procedure.
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Cytokinesis, the conclusive act of cell division, allows cytoplasmic organelles and chromosomes to be faithfully partitioned between two daughter cells. In animal organisms, its accurate regulation is a fundamental task for normal development and for preventing aneuploidy. Cytokinesis failures produce genetically unstable tetraploid cells and ultimately result in chromosome instability, a hallmark of cancer cells. In animal cells, the assembly and constriction of an actomyosin ring drive cleavage furrow ingression, resulting in the formation of a cytoplasmic intercellular bridge, which is severed during abscission, the final event of cytokinesis. Kinase-mediated phosphorylation is a crucial process to orchestrate the spatio-temporal regulation of the different stages of cytokinesis. Several kinases have been described in the literature, such as cyclin-dependent kinase, polo-like kinase 1, and Aurora B, regulating both furrow ingression and/or abscission. However, others exist, with well-established roles in cell-cycle progression but whose specific role in cytokinesis has been poorly investigated, leading to considering these kinases as "minor" actors in this process. Yet, they deserve additional attention, as they might disclose unexpected routes of cell division regulation. Here, we summarize the role of multifunctional kinases in cytokinesis with a special focus on those with a still scarcely defined function during cell cleavage. Moreover, we discuss their implication in cancer.
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Actomiosina , Citocinese , Animais , Citocinese/fisiologia , Divisão Celular , Fosforilação , Citoesqueleto de ActinaRESUMO
The oncoprotein GOLPH3 (Golgi phosphoprotein 3) is an evolutionarily conserved phosphatidylinositol 4-phosphate effector, mainly localized to the Golgi apparatus, where it supports organelle architecture and vesicular trafficking. Overexpression of human GOLPH3 correlates with poor prognosis in several cancer types and is associated with enhanced signaling downstream of mTOR (mechanistic target of rapamycin). However, the molecular link between GOLPH3 and mTOR remains elusive. Studies in Drosophila melanogaster have shown that Translationally controlled tumor protein (Tctp) and 14-3-3 proteins are required for organ growth by supporting the function of the small GTPase Ras homolog enriched in the brain (Rheb) during mTORC1 (mTOR complex 1) signaling. Here we demonstrate that Drosophila GOLPH3 (dGOLPH3) physically interacts with Tctp and 14-3-3ζ. RNAi-mediated knockdown of dGOLPH3 reduces wing and eye size and enhances the phenotypes of Tctp RNAi. This phenotype is partially rescued by overexpression of Tctp, 14-3-3ζ, or Rheb. We also show that the Golgi localization of Rheb in Drosophila cells depends on dGOLPH3. Consistent with dGOLPH3 involvement in Rheb-mediated mTORC1 activation, depletion of dGOLPH3 also reduces levels of phosphorylated ribosomal S6 kinase, a downstream target of mTORC1. Finally, the autophagy flux and the expression of autophagic transcription factors of the TFEB family, which anti correlates with mTOR signaling, are compromised upon reduction of dGOLPH3. Overall, our data provide the first in vivo demonstration that GOLPH3 regulates organ growth by directly associating with mTOR signaling proteins.
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Drosophila , Neuropeptídeos , Animais , Humanos , Drosophila/metabolismo , Drosophila melanogaster/metabolismo , Proteína Enriquecida em Homólogo de Ras do Encéfalo/metabolismo , Proteínas 14-3-3/metabolismo , Neuropeptídeos/genética , Serina-Treonina Quinases TOR/genética , Serina-Treonina Quinases TOR/metabolismo , Alvo Mecanístico do Complexo 1 de Rapamicina/metabolismo , Proteínas de Membrana/genética , Proteínas de Membrana/metabolismoRESUMO
Golgi phosphoprotein 3 (GOLPH3) is a highly conserved peripheral membrane protein localized to the Golgi apparatus and the cytosol. GOLPH3 binding to Golgi membranes depends on phosphatidylinositol 4-phosphate [PI(4)P] and regulates Golgi architecture and vesicle trafficking. GOLPH3 overexpression has been correlated with poor prognosis in several cancers, but the molecular mechanisms that link GOLPH3 to malignant transformation are poorly understood. We recently showed that PI(4)P-GOLPH3 couples membrane trafficking with contractile ring assembly during cytokinesis in dividing Drosophila spermatocytes. Here, we use affinity purification coupled with mass spectrometry (AP-MS) to identify the protein-protein interaction network (interactome) of Drosophila GOLPH3 in testes. Analysis of the GOLPH3 interactome revealed enrichment for proteins involved in vesicle-mediated trafficking, cell proliferation and cytoskeleton dynamics. In particular, we found that dGOLPH3 interacts with the Drosophila orthologs of Fragile X mental retardation protein and Ataxin-2, suggesting a potential role in the pathophysiology of disorders of the nervous system. Our findings suggest novel molecular targets associated with GOLPH3 that might be relevant for therapeutic intervention in cancers and other human diseases.
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Carcinogênese/metabolismo , Carcinogênese/patologia , Proteínas de Drosophila/metabolismo , Drosophila/metabolismo , Doenças do Sistema Nervoso/metabolismo , Sistema Nervoso/metabolismo , Proteínas Oncogênicas/metabolismo , Animais , Proliferação de Células/fisiologia , Citocinese/fisiologia , Citoesqueleto/metabolismo , Complexo de Golgi/metabolismo , Proteínas de Membrana/metabolismo , Fosfatos de Fosfatidilinositol/metabolismo , Mapas de Interação de Proteínas/fisiologia , Transporte Proteico/fisiologiaRESUMO
Glycosylation is the most common post-translational modification of proteins; it mediates their correct folding and stability, as well as their transport through the secretory transport. Changes in N- and O-linked glycans have been associated with multiple pathological conditions including congenital disorders of glycosylation, inflammatory diseases and cancer. Glycoprotein glycosylation at the Golgi involves the coordinated action of hundreds of glycosyltransferases and glycosidases, which are maintained at the correct location through retrograde vesicle trafficking between Golgi cisternae. In this review, we describe the molecular machinery involved in vesicle trafficking and tethering at the Golgi apparatus and the effects of mutations in the context of glycan biosynthesis and human diseases.
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Glicoproteínas/metabolismo , Glicosídeo Hidrolases/metabolismo , Glicosiltransferases/metabolismo , Complexo de Golgi/metabolismo , Animais , Glicosilação , Humanos , Estabilidade Proteica , Transporte ProteicoRESUMO
Coronary artery bypass grafting has long been the standard of care for patients with left main coronary artery (LMCA) disease. Lately, percutaneous coronary intervention (PCI) has become a suitable alternative for these patients, but the procedure may be challenging. We describe 2 cases of LMCA PCI failure requiring surgical intervention. (Level of Difficulty: Advanced.).
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Protein glycosylation, the enzymatic addition of N-linked or O-linked glycans to proteins, serves crucial functions in animal cells and requires the action of glycosyltransferases, glycosidases and nucleotide-sugar transporters, localized in the endoplasmic reticulum and Golgi apparatus. Congenital Disorders of Glycosylation (CDGs) comprise a family of multisystemic diseases caused by mutations in genes encoding proteins involved in glycosylation pathways. CDGs are classified into two large groups. Type I CDGs affect the synthesis of the dolichol-linked Glc3Man9GlcNac2 precursor of N-linked glycosylation or its transfer to acceptor proteins. Type II CDG (CDG-II) diseases impair either the trimming of the N-linked oligosaccharide, the addition of terminal glycans or the biosynthesis of O-linked oligosaccharides, which occur in the Golgi apparatus. So far, over 100 distinct forms of CDGs are known, with the majority of them characterized by neurological defects including mental retardation, seizures and hypotonia. Yet, it is unclear how defective glycosylation causes the pathology of CDGs. This issue can be only addressed by developing animal models of specific CDGs. Drosophila melanogaster is emerging as a highly suitable organism for analyzing glycan-dependent functions in the central nervous system (CNS) and the involvement of N-glycosylation in neuropathologies. In this review we illustrate recent work that highlights the genetic and neurobiologic advantages offered by D. melanogaster for dissecting glycosylation pathways and modeling CDG pathophysiology.
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Cytokinesis requires a tight coordination between actomyosin ring constriction and new membrane addition along the ingressing cleavage furrow. However, the molecular mechanisms underlying vesicle trafficking to the equatorial site and how this process is coupled with the dynamics of the contractile apparatus are poorly defined. Here we provide evidence for the requirement of Rab1 during cleavage furrow ingression in cytokinesis. We demonstrate that the gene omelette (omt) encodes the Drosophila orthologue of human Rab1 and is required for successful cytokinesis in both mitotic and meiotic dividing cells of Drosophila melanogaster We show that Rab1 protein colocalizes with the conserved oligomeric Golgi (COG) complex Cog7 subunit and the phosphatidylinositol 4-phosphate effector GOLPH3 at the Golgi stacks. Analysis by transmission electron microscopy and 3D-SIM super-resolution microscopy reveals loss of normal Golgi architecture in omt mutant spermatocytes indicating a role for Rab1 in Golgi formation. In dividing cells, Rab1 enables stabilization and contraction of actomyosin rings. We further demonstrate that GTP-bound Rab1 directly interacts with GOLPH3 and controls its localization at the Golgi and at the cleavage site. We propose that Rab1, by associating with GOLPH3, controls membrane trafficking and contractile ring constriction during cytokinesis.
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Proteínas de Drosophila/metabolismo , Drosophila melanogaster/fisiologia , Complexo de Golgi/metabolismo , Proteínas de Membrana/metabolismo , Proteínas Oncogênicas/metabolismo , Proteínas rab de Ligação ao GTP/metabolismo , Proteínas rab1 de Ligação ao GTP/metabolismo , Animais , Membrana Celular/metabolismo , Citocinese , Proteínas de Drosophila/genética , Drosophila melanogaster/metabolismo , Masculino , Transporte Proteico , Espermatócitos/metabolismo , Proteínas rab de Ligação ao GTP/genética , Proteínas rab1 de Ligação ao GTP/genéticaRESUMO
The highly conserved Golgi phosphoprotein 3 (GOLPH3) protein, a component of Trans-Golgi Network (TGN), has been defined as a "first-in-class Golgi oncoprotein" and characterized as a Phosphatidylinositol 4-phosphate [PI(4)P] effector at the Golgi. GOLPH3 is commonly amplified in several solid tumors. Furthermore this protein has been associated with poor prognosis in many cancers. Highly conserved from yeast to humans, GOLPH3 provides an essential function in vesicle trafficking and Golgi structure. Recent data have also implicated this oncoprotein in regulation of cytokinesis, modulation of mitochondrial mass and cellular response to DNA damage. A minute dissection of the molecular pathways that require GOLPH3 protein will be helpful to develop new therapeutic cancer strategies.