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1.
Mol Cell ; 75(2): 382-393.e5, 2019 07 25.
Artículo en Inglés | MEDLINE | ID: mdl-31229404

RESUMEN

The iron-sensing protein FBXL5 is the substrate adaptor for a SKP1-CUL1-RBX1 E3 ubiquitin ligase complex that regulates the degradation of iron regulatory proteins (IRPs). Here, we describe a mechanism of FBXL5 regulation involving its interaction with the cytosolic Fe-S cluster assembly (CIA) targeting complex composed of MMS19, FAM96B, and CIAO1. We demonstrate that the CIA-targeting complex promotes the ability of FBXL5 to degrade IRPs. In addition, the FBXL5-CIA-targeting complex interaction is regulated by oxygen (O2) tension displaying a robust association in 21% O2 that is severely diminished in 1% O2 and contributes to O2-dependent regulation of IRP degradation. Together, these data identify a novel oxygen-dependent signaling axis that links IRP-dependent iron homeostasis with the Fe-S cluster assembly machinery.


Asunto(s)
Proteínas de Ciclo Celular/genética , Proteínas F-Box/genética , Chaperonas Moleculares/genética , Complejos Multiproteicos/genética , Complejos de Ubiquitina-Proteína Ligasa/genética , Proteínas de Ciclo Celular/química , Proteínas F-Box/química , Células HeLa , Homeostasis , Humanos , Hierro/metabolismo , Proteínas Reguladoras del Hierro/genética , Proteínas Hierro-Azufre/química , Proteínas Hierro-Azufre/genética , Chaperonas Moleculares/química , Complejos Multiproteicos/química , Oxígeno/metabolismo , Proteolisis , Factores de Transcripción/genética , Complejos de Ubiquitina-Proteína Ligasa/química
2.
Mol Cell ; 75(2): 238-251.e5, 2019 07 25.
Artículo en Inglés | MEDLINE | ID: mdl-31348879

RESUMEN

BRCT domains support myriad protein-protein interactions involved in genome maintenance. Although di-BRCT recognition of phospho-proteins is well known to support the genotoxic response, whether multi-BRCT domains can acquire distinct structures and functions is unclear. Here we present the tetra-BRCT structures from the conserved yeast protein Rtt107 in free and ligand-bound forms. The four BRCT repeats fold into a tetrahedral structure that recognizes unmodified ligands using a bi-partite mechanism, suggesting repeat origami enabling function acquisition. Functional studies show that Rtt107 binding of partner proteins of diverse activities promotes genome replication and stability in both distinct and concerted manners. A unified theme is that tetra- and di-BRCT domains of Rtt107 collaborate to recruit partner proteins to chromatin. Our work thus illustrates how a master regulator uses two types of BRCT domains to recognize distinct genome factors and direct them to chromatin for constitutive genome protection.


Asunto(s)
Inestabilidad Genómica/genética , Proteínas Nucleares/ultraestructura , Dominios y Motivos de Interacción de Proteínas/genética , Proteínas de Saccharomyces cerevisiae/ultraestructura , Saccharomyces cerevisiae/genética , Cromatina/genética , Daño del ADN/genética , Ligandos , Proteínas Nucleares/química , Proteínas Nucleares/genética , Fosforilación , Unión Proteica , Dominios Proteicos/genética , Proteínas de Saccharomyces cerevisiae/química , Proteínas de Saccharomyces cerevisiae/genética
3.
Mol Cell ; 75(4): 859-874.e4, 2019 08 22.
Artículo en Inglés | MEDLINE | ID: mdl-31351878

RESUMEN

Homologous recombination (HR) is essential for high-fidelity DNA repair during mitotic proliferation and meiosis. Yet, context-specific modifications must tailor the recombination machinery to avoid (mitosis) or enforce (meiosis) the formation of reciprocal exchanges-crossovers-between recombining chromosomes. To obtain molecular insight into how crossover control is achieved, we affinity purified 7 DNA-processing enzymes that channel HR intermediates into crossovers or noncrossovers from vegetative cells or cells undergoing meiosis. Using mass spectrometry, we provide a global characterization of their composition and reveal mitosis- and meiosis-specific modules in the interaction networks. Functional analyses of meiosis-specific interactors of MutLγ-Exo1 identified Rtk1, Caf120, and Chd1 as regulators of crossing-over. Chd1, which transiently associates with Exo1 at the prophase-to-metaphase I transition, enables the formation of MutLγ-dependent crossovers through its conserved ability to bind and displace nucleosomes. Thus, rewiring of the HR network, coupled to chromatin remodeling, promotes context-specific control of the recombination outcome.


Asunto(s)
Intercambio Genético/fisiología , Meiosis/fisiología , Mitosis/fisiología , Proteínas de Saccharomyces cerevisiae/metabolismo , Saccharomyces cerevisiae/metabolismo , Espectrometría de Masas , Saccharomyces cerevisiae/genética , Proteínas de Saccharomyces cerevisiae/genética
4.
Mol Cell ; 69(1): 113-125.e6, 2018 01 04.
Artículo en Inglés | MEDLINE | ID: mdl-29225034

RESUMEN

The cytosolic iron-sulfur (Fe-S) cluster assembly (CIA) pathway functions to incorporate inorganic Fe-S cofactors into a variety of proteins, including several DNA repair enzymes. However, the mechanisms regulating the CIA pathway are unknown. We describe here that the MAGE-F1-NSE1 E3 ubiquitin ligase regulates the CIA pathway through ubiquitination and degradation of the CIA-targeting protein MMS19. Overexpression or knockout of MAGE-F1 altered Fe-S incorporation into MMS19-dependent DNA repair enzymes, DNA repair capacity, sensitivity to DNA-damaging agents, and iron homeostasis. Intriguingly, MAGE-F1 has undergone adaptive pseudogenization in select mammalian lineages. In contrast, MAGE-F1 is highly amplified in multiple human cancer types and amplified tumors have increased mutational burden. Thus, flux through the CIA pathway can be regulated by degradation of the substrate-specifying MMS19 protein and its downregulation is a common feature in cancer and is evolutionarily controlled.


Asunto(s)
Proteínas Portadoras/metabolismo , Reparación del ADN/genética , Hierro/química , Proteínas Asociadas a Microtúbulos/metabolismo , Proteínas de Neoplasias/metabolismo , Azufre/química , Factores de Transcripción/metabolismo , Animales , Sistemas CRISPR-Cas , Línea Celular Tumoral , Daño del ADN/genética , Células HEK293 , Células HeLa , Humanos , Proteínas Hierro-Azufre/metabolismo , Neoplasias Pulmonares/patología , Masculino , Ratones , Ratones Endogámicos NOD , Ratones SCID , Proteínas Asociadas a Microtúbulos/genética , Proteínas de Neoplasias/genética , Ubiquitinación
5.
Cell Mol Life Sci ; 81(1): 251, 2024 Jun 07.
Artículo en Inglés | MEDLINE | ID: mdl-38847937

RESUMEN

The Smc5/6 complex is a highly conserved molecular machine involved in the maintenance of genome integrity. While its functions largely depend on restraining the fork remodeling activity of Mph1 in yeast, the presence of an analogous Smc5/6-FANCM regulation in humans remains unknown. We generated human cell lines harboring mutations in the NSE1 subunit of the Smc5/6 complex. Point mutations or truncations in the RING domain of NSE1 result in drastically reduced Smc5/6 protein levels, with differential contribution of the two zinc-coordinating centers in the RING. In addition, nse1-RING mutant cells display cell growth defects, reduced replication fork rates, and increased genomic instability. Notably, our findings uncover a synthetic sick interaction between Smc5/6 and FANCM and show that Smc5/6 controls fork progression and chromosome disjunction in a FANCM-independent manner. Overall, our study demonstrates that the NSE1 RING domain plays vital roles in Smc5/6 complex stability and fork progression through pathways that are not evolutionary conserved.


Asunto(s)
Proteínas de Ciclo Celular , Replicación del ADN , Inestabilidad Genómica , Humanos , Proteínas de Ciclo Celular/metabolismo , Proteínas de Ciclo Celular/genética , Proteínas Cromosómicas no Histona/metabolismo , Proteínas Cromosómicas no Histona/genética , Dominios Proteicos , Estabilidad Proteica , Mutación , Línea Celular , ADN Helicasas
6.
Trends Biochem Sci ; 45(5): 411-426, 2020 05.
Artículo en Inglés | MEDLINE | ID: mdl-32311335

RESUMEN

Iron-sulfur (Fe-S) clusters (ISCs) are ubiquitous cofactors essential to numerous fundamental cellular processes. Assembly of ISCs and their insertion into apoproteins involves the function of complex cellular machineries that operate in parallel in the mitochondrial and cytosolic/nuclear compartments of mammalian cells. The spectrum of diseases caused by inherited defects in genes that encode the Fe-S assembly proteins has recently expanded to include multiple rare human diseases, which manifest distinctive combinations and severities of global and tissue-specific impairments. In this review, we provide an overview of our understanding of ISC biogenesis in mammalian cells, discuss recent work that has shed light on the molecular interactions that govern ISC assembly, and focus on human diseases caused by failures of the biogenesis pathway.


Asunto(s)
Proteínas Hierro-Azufre/metabolismo , Citosol/metabolismo , ADN/metabolismo , Mitocondrias/metabolismo , ARN/metabolismo
7.
J Bacteriol ; 206(6): e0000824, 2024 06 20.
Artículo en Inglés | MEDLINE | ID: mdl-38819153

RESUMEN

Magnetotactic bacteria are a diverse group of microbes that use magnetic particles housed within intracellular lipid-bounded magnetosome organelles to guide navigation along geomagnetic fields. The development of magnetosomes and their magnetic crystals in Magnetospirillum magneticum AMB-1 requires the coordinated action of numerous proteins. Most proteins are thought to localize to magnetosomes during the initial stages of organelle biogenesis, regardless of environmental conditions. However, the magnetite-shaping protein Mms6 is only found in magnetosomes that contain magnetic particles, suggesting that it might conditionally localize after the formation of magnetosome membranes. The mechanisms for this unusual mode of localization to magnetosomes are unclear. Here, using pulse-chase labeling, we show that Mms6 translated under non-biomineralization conditions translocates to pre-formed magnetosomes when cells are shifted to biomineralizing conditions. Genes essential for magnetite production, namely mamE, mamM, and mamO, are necessary for Mms6 localization, whereas mamN inhibits Mms6 localization. MamD localization was also investigated and found to be controlled by similar cellular factors. The membrane localization of Mms6 is dependent on a glycine-leucine repeat region, while the N-terminal domain of Mms6 is necessary for retention in the cytosol and impacts conditional localization to magnetosomes. The N-terminal domain is also sufficient to impart conditional magnetosome localization to MmsF, altering its native constitutive magnetosome localization. Our work illuminates an alternative mode of protein localization to magnetosomes in which Mms6 and MamD are excluded from magnetosomes by MamN until biomineralization initiates, whereupon they translocate into magnetosome membranes to control the development of growing magnetite crystals.IMPORTANCEMagnetotactic bacteria (MTB) are a diverse group of bacteria that form magnetic nanoparticles surrounded by membranous organelles. MTB are widespread and serve as a model for bacterial organelle formation and biomineralization. Magnetosomes require a specific cohort of proteins to enable magnetite formation, but how those proteins are localized to magnetosome membranes is unclear. Here, we investigate protein localization using pulse-chase microscopy and find a system of protein coordination dependent on biomineralization-permissible conditions. In addition, our findings highlight a protein domain that alters the localization behavior of magnetosome proteins. Utilization of this protein domain may provide a synthetic route for conditional functionalization of magnetosomes for biotechnological applications.


Asunto(s)
Proteínas Bacterianas , Magnetosomas , Magnetospirillum , Magnetospirillum/genética , Magnetospirillum/metabolismo , Magnetosomas/metabolismo , Magnetosomas/genética , Proteínas Bacterianas/metabolismo , Proteínas Bacterianas/genética , Regulación Bacteriana de la Expresión Génica , Transporte de Proteínas
8.
Genet Med ; 26(6): 101104, 2024 06.
Artículo en Inglés | MEDLINE | ID: mdl-38411040

RESUMEN

PURPOSE: The functionality of many cellular proteins depends on cofactors; yet, they have only been implicated in a minority of Mendelian diseases. Here, we describe the first 2 inherited disorders of the cytosolic iron-sulfur protein assembly system. METHODS: Genetic testing via genome sequencing was applied to identify the underlying disease cause in 3 patients with microcephaly, congenital brain malformations, progressive developmental and neurologic impairments, recurrent infections, and a fatal outcome. Studies in patient-derived skin fibroblasts and zebrafish models were performed to investigate the biochemical and cellular consequences. RESULTS: Metabolic analysis showed elevated uracil and thymine levels in body fluids but no pathogenic variants in DPYD, encoding dihydropyrimidine dehydrogenase. Genome sequencing identified compound heterozygosity in 2 patients for missense variants in CIAO1, encoding cytosolic iron-sulfur assembly component 1, and homozygosity for an in-frame 3-nucleotide deletion in MMS19, encoding the MMS19 homolog, cytosolic iron-sulfur assembly component, in the third patient. Profound alterations in the proteome, metabolome, and lipidome were observed in patient-derived fibroblasts. We confirmed the detrimental effect of deficiencies in CIAO1 and MMS19 in zebrafish models. CONCLUSION: A general failure of cytosolic and nuclear iron-sulfur protein maturation caused pleiotropic effects. The critical function of the cytosolic iron-sulfur protein assembly machinery for antiviral host defense may well explain the recurrent severe infections occurring in our patients.


Asunto(s)
Proteínas Hierro-Azufre , Pez Cebra , Animales , Humanos , Proteínas Hierro-Azufre/genética , Proteínas Hierro-Azufre/metabolismo , Masculino , Femenino , Fenotipo , Fibroblastos/metabolismo , Fibroblastos/patología , Citosol/metabolismo , Enfermedades Neurodegenerativas/genética , Enfermedades Neurodegenerativas/metabolismo , Enfermedades Neurodegenerativas/patología , Microcefalia/genética , Microcefalia/patología , Lactante , Metalochaperonas
9.
J Am Acad Dermatol ; 91(3): 499-507, 2024 Sep.
Artículo en Inglés | MEDLINE | ID: mdl-38768857

RESUMEN

Mohs Micrographic Surgery (MMS) for treatment of melanoma offers several advantages over wide local excision (WLE), including complete histologic margin evaluation, same-day resection and closure, and sparing of healthy tissue in critical anatomic sites. Recently, a large volume of clinical data demonstrating efficacy in MMS treatment of melanoma was published, leading to emerging patient safety considerations of incurred treatment costs, risk of tumor upstaging, and failure of care coordination for sentinel lymph node biopsy (SLNB). MMS offers a safe, effective, and value-based treatment for both melanoma in situ (MIS) and invasive melanoma (IM), particularly with immunohistochemistry use on frozen sections. Compared to wide local excision, MMS treatment demonstrates similar or improved outcomes for local tumor recurrence, melanoma-specific survival, and overall survival at long-term follow-up. Tumor upstaging risk is low, and if present, alteration to clinical management is minimal. Discussion of SLNB for eligible head and neck IM cases should be done prior to MMS. Though challenging, successful multidisciplinary coordination of SLNB with MMS has been demonstrated. Herein, we provide a detailed clinical review of evidence for MMS treatment of cutaneous melanoma and offer recommendations to address current controversies surrounding the evolving paradigm of surgical management for both MIS and invasive melanoma (IM).


Asunto(s)
Melanoma , Cirugía de Mohs , Invasividad Neoplásica , Biopsia del Ganglio Linfático Centinela , Neoplasias Cutáneas , Cirugía de Mohs/métodos , Humanos , Melanoma/cirugía , Melanoma/patología , Neoplasias Cutáneas/cirugía , Neoplasias Cutáneas/patología , Recurrencia Local de Neoplasia/prevención & control , Recurrencia Local de Neoplasia/epidemiología , Resultado del Tratamiento , Márgenes de Escisión , Estadificación de Neoplasias
10.
Genes Dev ; 30(8): 931-45, 2016 Apr 15.
Artículo en Inglés | MEDLINE | ID: mdl-27056668

RESUMEN

High-resolution imaging shows that persistent DNA damage in budding yeast localizes in distinct perinuclear foci for repair. The signals that trigger DNA double-strand break (DSB) relocation or determine their destination are unknown. We show here that DSB relocation to the nuclear envelope depends on SUMOylation mediated by the E3 ligases Siz2 and Mms21. In G1, a polySUMOylation signal deposited coordinately by Mms21 and Siz2 recruits the SUMO targeted ubiquitin ligase Slx5/Slx8 to persistent breaks. Both Slx5 and Slx8 are necessary for damage relocation to nuclear pores. When targeted to an undamaged locus, however, Slx5 alone can mediate relocation in G1-phase cells, bypassing the requirement for polySUMOylation. In contrast, in S-phase cells, monoSUMOylation mediated by the Rtt107-stabilized SMC5/6-Mms21 E3 complex drives DSBs to the SUN domain protein Mps3 in a manner independent of Slx5. Slx5/Slx8 and binding to pores favor repair by ectopic break-induced replication and imprecise end-joining.


Asunto(s)
Roturas del ADN de Doble Cadena , Poro Nuclear/metabolismo , Proteína SUMO-1/metabolismo , Proteínas de Saccharomyces cerevisiae/metabolismo , Saccharomyces cerevisiae/genética , Saccharomyces cerevisiae/metabolismo , Sumoilación , Mutación , Membrana Nuclear/metabolismo , Unión Proteica , Fase S/fisiología , Saccharomyces cerevisiae/citología , Ubiquitina-Proteína Ligasas/metabolismo
11.
New Phytol ; 239(3): 920-935, 2023 08.
Artículo en Inglés | MEDLINE | ID: mdl-37209253

RESUMEN

Drought stress causes substantial losses in crop production per year worldwide, threatening global food security. Identification of the genetic components underlying drought tolerance in plants is of great importance. In this study, we report that loss-of-function of the chromatin-remodeling factor PICKLE (PKL), which is involved in repression of transcription, enhances drought tolerance of Arabidopsis. At first, we find that PKL interacts with ABI5 to regulate seed germination, but PKL regulates drought tolerance independently of ABI5. Then, we find that PKL is necessary for repressing the drought-tolerant gene AFL1, which is responsible for the drought-tolerant phenotype of pkl mutant. Genetic complementation tests demonstrate that the Chromo domain and ATPase domain but not the PHD domain are required for the function of PKL in regulating drought tolerance. Interestingly, we find that the DNA-binding domain (DBD) is essential for the protein stability of PKL. Furthermore, we demonstrate that the SUMO E3 ligase MMS21 interacts with and enhances the protein stability of PKL. Genetic interaction analysis shows that MMS21 and PKL additively regulate plant drought tolerance. Collectively, our findings uncover a MMS21-PKL-AFL1 module in regulating plant drought tolerance and offer insights into a novel strategy to improve crop drought tolerance.


Asunto(s)
Proteínas de Arabidopsis , Arabidopsis , Arabidopsis/metabolismo , Proteínas de Arabidopsis/metabolismo , Resistencia a la Sequía , Factores de Transcripción/genética , Factores de Transcripción/metabolismo , Sequías , Regulación de la Expresión Génica de las Plantas
12.
J Am Acad Dermatol ; 89(4): 734-744, 2023 10.
Artículo en Inglés | MEDLINE | ID: mdl-37307991

RESUMEN

BACKGROUND: Malignant melanoma in-situ, lentigo maligna (MMIS-LM) can be successfully treated with several different surgical techniques; however, the literature is inconsistent in defining them. OBJECTIVE: To comprehensively define and describe the national guideline recommended surgical techniques used to treat MMIS-LM to help clarify and standardize this terminology to ensure compliance with the guidelines. METHODS: A targeted literature review was performed from 1990 to 2022 focusing on articles that discussed the national guideline recommended surgical techniques of wide local excision, Mohs micrographic surgery (MMS), modified Mohs surgery, and staged excision/Slow-Mohs for MMIS-LM, as well as the related methods of tissue processing. National Comprehensive Cancer Network and American Academy of Dermatology guidelines were reviewed to identify how the techniques need to be employed to be compliant with guideline recommendations. RESULTS: We describe the various surgical and tissue processing techniques and discuss advantages and disadvantages of each. LIMITATIONS: This paper was styled as a narrative review defining and clarifying terminology and technique and does not investigate these topics more broadly. CONCLUSION: Understanding the methodology and terminology for these surgical procedures and tissue processing methods is critical so that both general dermatologists and surgeons can employ these techniques effectively for optimal patient care.


Asunto(s)
Peca Melanótica de Hutchinson , Melanoma , Neoplasias Cutáneas , Humanos , Peca Melanótica de Hutchinson/patología , Adhesión a Directriz , Melanoma/patología , Neoplasias Cutáneas/patología , Cirugía de Mohs/métodos , Melanoma Cutáneo Maligno
13.
Sensors (Basel) ; 23(5)2023 Feb 21.
Artículo en Inglés | MEDLINE | ID: mdl-36904572

RESUMEN

The emergence of autonomous vehicles marks a shift in mobility. Conventional vehicles have been designed to prioritize the safety of drivers and passengers and increase fuel efficiency, while autonomous vehicles are developing as convergence technologies with a focus on more than just transportation. With the potential for autonomous vehicles to serve as an office or leisure space, the accuracy and stability of their driving technology is of utmost importance. However, commercializing autonomous vehicles has been challenging due to the limitations of current technology. This paper proposes a method to build a precision map for multi-sensor-based autonomous driving to improve the accuracy and stability of autonomous vehicle technology. The proposed method leverages dynamic high-definition maps to enhance the recognition rates and autonomous driving path recognition of objects in the vicinity of the vehicle, utilizing multiple sensors such as cameras, LIDAR, and RADAR. The goal is to improve the accuracy and stability of autonomous driving technology.

14.
Sensors (Basel) ; 23(10)2023 May 16.
Artículo en Inglés | MEDLINE | ID: mdl-37430705

RESUMEN

In the wide scenario of heritage documentation and conservation, the multi-scale nature of digital models is able to twin the real object, as well as to store information and record investigation results, in order to detect and analyse deformation and materials deterioration, especially from a structural point of view. The contribution proposes an integrated approach for the generation of an n-D enriched model, also called a digital twin, able to support the interdisciplinary investigation process conducted on the site and following the processing of the collected data. Particularly for 20th Century concrete heritage, an integrated approach is required in order to adapt the more consolidated approaches to a new conception of the spaces, where structure and architecture are often coincident. The research plans to present the documentation process for the halls of Torino Esposizioni (Turin, Italy), built in the mid-twentieth century and designed by Pier Luigi Nervi. The HBIM paradigm is explored and expanded in order to fulfil the multi-source data requirements and adapt the consolidated reverse modelling processes based on scan-to-BIM solutions. The most relevant contributions of the research reside in the study of the chances of using and adapting the characteristics of the IFC (Industry Foundation Classes) standard to the archiving needs of the diagnostic investigations results so that the digital twin model can meet the requirements of replicability in the context of the architectural heritage and interoperability with respect to the subsequent intervention phases envisaged by the conservation plan. Another crucial innovation is a proposal of a scan-to-BIM process improved by an automated approach performed by VPL (Visual Programming Languages) contribution. Finally, an online visualisation tool enables the HBIM cognitive system to be accessible and shareable by stakeholders involved in the general conservation process.

15.
J Environ Manage ; 325(Pt A): 116455, 2023 Jan 01.
Artículo en Inglés | MEDLINE | ID: mdl-36242975

RESUMEN

The in-situ resource utilisation (ISRU), in terms of native rocky materials and astronaut wastes, is crucial in contests of soil-based space-farming. Nevertheless, extra-terrestrial soils are very different from Earth soils, lacking any form of organic carbon and associated macro and micronutrients. In this research, we aimed to study and modify two commercially available Lunar and Martian regolith simulants (LHS-1 from Exolith Lab and MMS-1 from Martian Garden) to make them an adequate medium for plant growth. Lettuce was chosen as reference crop to guide the discussion on the results obtained. To reach this main objective, we added to simulants a commercially available monogastric-based organic manure chosen as a substitute of a possible organic amendment produced onboard. The simulant/manure mixture rates were 100:0, 90:10, 70:30, 50:50; w:w. As expected, an approximately linear increase of total and bioavailable contents of macro (N, S, P, Ca, K, Mg) and micro (Fe, Mn, Cu, Zn) nutrients with increasing manure addition to simulants was observed. On the other hand, the very high pH of manure (pH, 9.02) along with its salinity (EC, 6.7 dS m-1) and sodicity (Na, 5.3 g kg-1), did not correct the already high pH of simulants (very high for LHS-1), but rather raised their soluble salt content and sodium amount on the exchange complex. In addition, an increase of toxic soluble aluminium and heavy elements (Pb, Ni, Cr, V) was observed, mainly in the strongly alkaline lunar simulant/manure mixtures. The addition of an organic source also produced a generalised improvement of water retention and hydraulic conductivity of both regolith simulants, in proportion to the percentage of manure addiction. For both situations, the best mixture ratio was 70:30. In terms of water retained, the LHS-1 mixtures benefited more than the MMS-1 ones by manure addition since water was held more in the "dry" (between -100 and -600 cm of matric potential head) than in the "humid" (between -25 and -100 cm of matric potential head) region of water retention. This would make LHS-1 mixtures more useful for cultivation of lettuce, at least in terms of physico-hydraulic properties. Nevertheless, the overall characterisation of the mixtures unveiled that MMS-1-based substrates can ensure better agronomic performances than LHS-1 ones, mainly due to lower pHs and higher nutrient availability; this divergent fertility was particularly evident at 90:10 simulant/manure rate and tend to be mitigated by increasing the levels of manure.


Asunto(s)
Estiércol , Marte , Suelo/química , Medio Ambiente Extraterrestre , Lactuca , Agua
16.
Neurosurg Rev ; 46(1): 25, 2022 Dec 27.
Artículo en Inglés | MEDLINE | ID: mdl-36574089

RESUMEN

The Berlin Grading System assesses clinical severity of moyamoya angiopathy (MMA) by combining MRI, DSA, and cerebrovascular reserve capacity (CVRC). Our aim was to validate this grading system using [15O]H2O PET for CVRC. We retrospectively identified bilateral MMA patients who underwent [15O]H2O PET examination and were treated surgically at our department. Each hemisphere was classified using the Suzuki and Berlin Grading System. Preoperative symptoms and perioperative ischemias were collected, and a logistic regression analysis was performed. A total of 100 hemispheres in 50 MMA patients (36 women, 14 men) were included. Using the Berlin Grading System, 2 (2.8%) of 71 symptomatic hemispheres were categorized as grade I, 14 (19.7%) as grade II, and 55 (77.5%) as grade III. The 29 asymptomatic hemispheres were characterized as grade I in 7 (24.1%) hemispheres, grade II in 12 (41.4%), and grade III in 10 (34.5%) hemispheres. Berlin grades were independent factors for identifying hemispheres as symptomatic and higher grades correlated with increasing proportion of symptomatic hemispheres (p < 0.01). The Suzuki grading did not correlate with preoperative symptoms (p = 0.26). Perioperative ischemic complications occurred in 8 of 88 operated hemispheres. Overall, complications did not occur in any of the grade I hemispheres, but in 9.1% (n = 2 of 22) and 9.8% (n = 6 of 61) of grade II and III hemispheres, respectively. In this study, we validated the Berlin Grading System with the use of [15O]H2O PET for CVRC as it could stratify preoperative symptomatology. Furthermore, we highlighted its relevance for predicting perioperative ischemic complications.


Asunto(s)
Revascularización Cerebral , Enfermedad de Moyamoya , Masculino , Humanos , Femenino , Estudios Retrospectivos , Enfermedad de Moyamoya/diagnóstico por imagen , Enfermedad de Moyamoya/cirugía , Imagen por Resonancia Magnética , Revascularización Cerebral/efectos adversos , Tomografía de Emisión de Positrones
17.
Int J Mol Sci ; 23(18)2022 Sep 07.
Artículo en Inglés | MEDLINE | ID: mdl-36142217

RESUMEN

Magnetosomes of magnetotactic bacteria consist of magnetic nanocrystals with defined morphologies enclosed in vesicles originated from cytoplasmic membrane invaginations. Although many proteins are involved in creating magnetosomes, a single magnetosome protein, Mms6 from Magnetospirillum magneticum strain AMB-1, can direct the crystallization of magnetite nanoparticles in vitro. The in vivo role of Mms6 in magnetosome formation is debated, and the observation that Mms6 binds Fe3+ more tightly than Fe2+ raises the question of how, in a magnetosome environment dominated by Fe3+, Mms6 promotes the crystallization of magnetite, which contains both Fe3+ and Fe2+. Here we show that Mms6 is a ferric reductase that reduces Fe3+ to Fe2+ using NADH and FAD as electron donor and cofactor, respectively. Reductase activity is elevated when Mms6 is integrated into either liposomes or bicelles. Analysis of Mms6 mutants suggests that the C-terminal domain binds iron and the N-terminal domain contains the catalytic site. Although Mms6 forms multimers that involve C-terminal and N-terminal domain interactions, a fusion protein with ubiquitin remains a monomer and displays reductase activity, which suggests that the catalytic site is fully in the monomer. However, the quaternary structure of Mms6 appears to alter the iron binding characteristics of the C-terminal domain. These results are consistent with a hypothesis that Mms6, a membrane protein, promotes the formation of magnetite in vivo by a mechanism that involves reducing iron.


Asunto(s)
Magnetosomas , Magnetospirillum , Proteínas Bacterianas/química , FMN Reductasa/metabolismo , Óxido Ferrosoférrico/metabolismo , Flavina-Adenina Dinucleótido/metabolismo , Hierro/metabolismo , Lípidos/análisis , Liposomas/metabolismo , Magnetosomas/metabolismo , Magnetospirillum/metabolismo , Proteínas de la Membrana/metabolismo , NAD/metabolismo , Ubiquitinas/metabolismo
18.
J Integr Plant Biol ; 64(1): 87-104, 2022 Jan.
Artículo en Inglés | MEDLINE | ID: mdl-34859586

RESUMEN

Arabidopsis methylation elevated mutant 1 (mem1) mutants have elevated levels of global DNA methylation. In this study, such mutant alleles showed increased sensitivity to methyl methanesulfonate (MMS). In mem1 mutants, an assortment of genes engaged in DNA damage response (DDR), especially DNA-repair-associated genes, were largely upregulated without MMS treatment, suggestive of activation of the DDR pathway in them. Following MMS treatment, expression levels of multiple DNA-repair-associated genes in mem1 mutants were generally lower than in Col-0 plants, which accounted for the MMS-sensitive phenotype of the mem1 mutants. A group of DNA methylation pathway genes were upregulated in mem1 mutants under non-MMS-treated conditions, causing elevated global DNA methylation, especially in RNA-directed DNA methylation (RdDM)-targeted regions. Moreover, MEM1 seemed to help ATAXIA-TELANGIECTASIA MUTATED (ATM) and/or SUPPRESSOR OF GAMMA RESPONSE 1 (SOG1) to fully activate/suppress transcription of a subset of genes regulated simultaneously by MEM1 and ATM and/or SOG1, because expression of such genes decreased/increased consistently in mem1 and atm and/or sog1 mutants, but the decreases/increases in the mem1 mutants were not as dramatic as in the atm and/or sog1 mutants. Thus, our studies reveals roles of MEM1 in safeguarding genome, and interrelationships among DNA damage, activation of DDR, DNA methylation/demethylation, and DNA repair.


Asunto(s)
Proteínas de Arabidopsis , Arabidopsis , Arabidopsis/genética , Arabidopsis/metabolismo , Proteínas de Arabidopsis/genética , Proteínas de Arabidopsis/metabolismo , Proteínas de la Ataxia Telangiectasia Mutada , Daño del ADN/genética , Metilación de ADN/genética , Reparación del ADN/genética , Regulación de la Expresión Génica de las Plantas , Factores de Transcripción/metabolismo
19.
Foot Ankle Surg ; 28(1): 20-24, 2022 Jan.
Artículo en Inglés | MEDLINE | ID: mdl-33500217

RESUMEN

BACKGROUND: The use of smartphones and multimedia messaging service (MMS) continues to increase in day to day orthopaedic clinical practice. However, there is limited evidence to support the safe utilisation of MMS. OBJECTIVES: The aim of this study was to correlate the performance of MMS imaging to picture archiving and communication systems (PACS) imaging within the setting of diagnosis and management of ankle fractures. METHODS: The ankle fracture radiograph series of 82 consecutive patients were evaluated by five orthopaedic consultant specialists. A questionnaire regarding diagnosis and preferred management was completed separately for each patient using smartphone and PACS images. Statistical analysis was performed using Intraclass Correlation Coefficient (ICC). RESULTS: Ankle fracture diagnosis showed strong to excellent correlation both inter- and intraobserver MMS vs PACS when using the Weber (0.815, 0.988), Anatomical (0.858, 0.988), and AO classification systems (0.855, 0.985). MMS was less reliable than PACS in determining many management options. CONCLUSION: The reliability of ankle fracture classification using MMS image viewing was not significantly different to interpretation on PACS workstations. Smartphone use in ankle fracture classification is supported by this study. Smartphone use was less accurate than PACS in devising management plans and future use should be limited to making only initial plans that must be corroberated with PACS and intraoperative findings prior to definitive fixation.


Asunto(s)
Fracturas de Tobillo , Teléfono Inteligente , Fracturas de Tobillo/diagnóstico por imagen , Fracturas de Tobillo/cirugía , Humanos , Multimedia , Radiografía , Reproducibilidad de los Resultados
20.
Development ; 145(2)2018 01 25.
Artículo en Inglés | MEDLINE | ID: mdl-29361561

RESUMEN

Mms19 encodes a cytosolic iron-sulphur assembly component. We found that Drosophila Mms19 is also essential for mitotic divisions and for the proliferation of diploid cells. Reduced Mms19 activity causes severe mitotic defects in spindle dynamics and chromosome segregation, and loss of zygotic Mms19 prevents the formation of imaginal discs. The lack of mitotic tissue in Mms19P/P larvae can be rescued by overexpression of the Cdk-activating kinase (CAK) complex, an activator of mitotic Cdk1, suggesting that Mms19 functions in mitosis to allow CAK (Cdk7/Cyclin H/Mat1) to become fully active as a Cdk1-activating kinase. When bound to Xpd and TFIIH, the CAK subunit Cdk7 phosphorylates transcriptional targets and not cell cycle Cdks. In contrast, free CAK phosphorylates and activates Cdk1. Physical and genetic interaction studies between Mms19 and Xpd suggest that their interaction prevents Xpd from binding to the CAK complex. Xpd bound to Mms19 therefore frees CAK complexes, allowing them to phosphorylate Cdk1 and facilitating progression to metaphase. The structural basis for the competitive interaction with Xpd seems to be the binding of Mms19, core TFIIH and CAK to neighbouring or overlapping regions of Xpd.


Asunto(s)
Quinasa 9 Dependiente de la Ciclina/metabolismo , ADN Helicasas/metabolismo , Proteínas de Drosophila/metabolismo , Mitosis/fisiología , Factores de Transcripción/metabolismo , Animales , Quinasa 9 Dependiente de la Ciclina/genética , ADN Helicasas/genética , Proteínas de Drosophila/genética , Drosophila melanogaster , Activación Enzimática/fisiología , Factores de Transcripción/genética
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