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1.
Novel ASCC1 mutations causing prenatal-onset muscle weakness with arthrogryposis and congenital bone fractures.
Böhm, J, Malfatti, E, Oates, E, Jones, K, Brochier, G, Boland, A, Deleuze, JF, Romero, NB, Laporte, J
Journal of medical genetics. 2019;(9):617-621
Abstract
BACKGROUND The activating signal cointegrator 1 (ASC-1) complex acts as a transcriptional coactivator for a variety of transcription factors and consists of four subunits: ASCC1, ASCC2, ASCC3 and TRIP4. A single homozygous mutation in ASCC1 has recently been reported in two families with a severe muscle and bone disorder. OBJECTIVE We aim to contribute to a better understanding of the ASCC1-related disorder. METHODS Here, we provide a clinical, histological and genetic description of three additional ASCC1 families. RESULTS All patients presented with severe prenatal-onset muscle weakness, neonatal hypotonia and arthrogryposis, and congenital bone fractures. The muscle biopsies from the affected infants revealed intense oxidative rims beneath the sarcolemma and scattered remnants of sarcomeres with enlarged Z-bands, potentially representing a histopathological hallmark of the disorder. Sequencing identified recessive nonsense or frameshift mutations in ASCC1, including two novel mutations. CONCLUSION Overall, this work expands the ASCC1 mutation spectrum, sheds light on the muscle histology of the disorder and emphasises the physiological importance of the ASC-1 complex in fetal muscle and bone development.
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2.
Novel IFT140 variants cause spermatogenic dysfunction in humans.
Wang, X, Sha, YW, Wang, WT, Cui, YQ, Chen, J, Yan, W, Hou, XT, Mei, LB, Yu, CC, Wang, J
Molecular genetics & genomic medicine. 2019;(9):e920
Abstract
BACKGROUND The intraflagellar transport protein 140 homolog (IFT140) is involved in the process of intraflagellar transport (IFT), a process that is essential for the formation and maintenance of most eukaryotic cilia and flagella. Variants IFT140 have been reported to account for ciliopathy but association with male fertility has never been described in humans. Here we report the identification of two novel variants of IFT140 which caused spermatogenic dysfunction and male infertility. METHODS Whole-exome sequencing was performed in a 27-year-old infertile man presented with severe oligozoospermia, asthenozoospermia, and teratozoospermia (OAT) without other physical abnormality. Sanger sequencing was used to verify gene variants in the patient, his healthy brother, and their parents. Morphology and protein expression in the patient's sperm were examined by transmission electron microscopy (TEM) and immunofluorescence staining. Function of gene variants was predicted by online databases. RESULTS Compound heterozygous variants of IFT140: exon16: c.1837G > A: p.Asp613Asn and exon31: c.4247G > A: p.Ser1416Asn were identified in the patient, both of which showed autosomal recessive inheritance in his family, and had extremely low allele frequency in the population. Morphological abnormalities of the head, nucleus, and tails and the absence of IFT140 from the neck and mid-piece of the patient's spermatozoa were observed. Mutation Taster database predicted a high probability of damage-causing by both variations. CONCLUSION This study for the first time reported IFT140 variants that cause infertility in humans.
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3.
Transition metal transporters in rhizobia: tuning the inorganic micronutrient requirements to different living styles.
Abreu, I, Mihelj, P, Raimunda, D
Metallomics : integrated biometal science. 2019;(4):735-755
Abstract
A group of bacteria known as rhizobia are key players in symbiotic nitrogen fixation (SNF) in partnership with legumes. After a molecular exchange, the bacteria end surrounded by a plant membrane forming symbiosomes, organelle-like structures, where they differentiate to bacteroids and fix nitrogen. This symbiotic process is highly dependent on dynamic nutrient exchanges between the partners. Among these are transition metals (TM) participating as inorganic and organic cofactors of fundamental enzymes. While the understanding of how plant transporters facilitate TMs to the very near environment of the bacteroid is expanding, our knowledge on how bacteroid transporters integrate to TM homeostasis mechanisms in the plant host is still limited. This is significantly relevant considering the low solubility and scarcity of TMs in soils, and the in crescendo gradient of TM bioavailability rhizobia faces during the infection and bacteroid differentiation processes. In the present work, we review the main metal transporter families found in rhizobia, their role in free-living conditions and, when known, in symbiosis. We focus on discussing those transporters which could play a significant role in TM-dependent biochemical and physiological processes in the bacteroid, thus paving the way towards an optimized SNF.
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4.
Predictive value of AZGP1 following radical prostatectomy for prostate cancer: a cohort study and meta-analysis.
Kristensen, G, Berg, KD, Toft, BG, Stroomberg, HV, Nolley, R, Brooks, JD, Brasso, K, Roder, MA
Journal of clinical pathology. 2019;(10):696-704
Abstract
AIMS: Zinc-alpha 2-glycoprotein (AZGP1) is a promising tissue biomarker to predict outcomes in men undergoing treatment for localised prostate cancer (PCa). We aimed to examine the association between AZGP1 expression and the endpoints: risk of biochemical failure (BF), initiating castration-based treatment, developing castration-resistant PCa (CRPC) and PCa-specific mortality following radical prostatectomy (RP). METHODS The study included a prospective cohort of 302 patients who underwent RP for PCa from 2002 to 2005. AZGP1 expression was analysed using immunohistochemistry on tissue microarray RP specimens and was scored semiquantitively as low or high expression. Risk of all endpoints was analysed using stratified cumulative incidences and cause-specific Cox regression, and validated with receiver operating curves, calibration and discrimination in competing-risk analyses. A meta-analysis was performed including previous studies investigating AZGP1 expression and risk of BF following RP. RESULTS Median time of follow-up was 14.0 years. The cumulative incidence of all endpoints was significantly higher in patients with low AZGP1 expression compared with patients with high AZGP1 expression (p<0.001). In a multivariate analysis, low AZGP1 expression increases the risk of BF (HR 2.7; 95% CI 1.9 to 3.8; p<0.0001), castration-based treatment (HR 2.2; 95% CI 1.2 to 4.2; p=0.01) and CRPC (HR 2.3; 95% CI 1.1 to 5.0; p=0.03). Validation showed a low risk of prediction error and a high model performance for all endpoints. In a meta-analysis, low AZGP1 was associated with BF (HR 1.7; 95% CI 1.2 to 2.5). CONCLUSIONS Low AZGP1 expression is associated with the risk of aggressive time-dependent outcomes in men undergoing RP for localised PCa.
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5.
Structural properties of [2Fe-2S] ISCA2-IBA57: a complex of the mitochondrial iron-sulfur cluster assembly machinery.
Nasta, V, Da Vela, S, Gourdoupis, S, Ciofi-Baffoni, S, Svergun, DI, Banci, L
Scientific reports. 2019;(1):18986
Abstract
In mitochondria, a complex protein machinery is devoted to the maturation of iron-sulfur cluster proteins. Structural information on the last steps of the machinery, which involve ISCA1, ISCA2 and IBA57 proteins, needs to be acquired in order to define how these proteins cooperate each other. We report here the use of an integrative approach, utilizing information from small-angle X-ray scattering (SAXS) and bioinformatics-driven docking prediction, to determine a low-resolution structural model of the human mitochondrial [2Fe-2S]2+ ISCA2-IBA57 complex. In the applied experimental conditions, all the data converge to a structural organization of dimer of dimers for the [2Fe-2S]2+ ISCA2-IBA57 complex with ISCA2 providing the homodimerization core interface. The [2Fe-2S] cluster is out of the ISCA2 core while being shared with IBA57 in the dimer. The specific interaction pattern identified from the dimeric [2Fe-2S]2+ ISCA2-IBA57 structural model allowed us to define the molecular grounds of the pathogenic Arg146Trp mutation of IBA57. This finding suggests that the dimeric [2Fe-2S] ISCA2-IBA57 hetero-complex is a physiologically relevant species playing a role in mitochondrial [4Fe-4S] protein biogenesis.
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6.
The SUF system: an ABC ATPase-dependent protein complex with a role in Fe-S cluster biogenesis.
Garcia, PS, Gribaldo, S, Py, B, Barras, F
Research in microbiology. 2019;(8):426-434
Abstract
Iron-sulfur (Fe-S) clusters are considered one of the most ancient and versatile inorganic cofactors present in the three domains of life. Fe-S clusters can act as redox sensors or catalysts and are found to be used by a large number of functional and structurally diverse proteins. Here, we cover current knowledge of the SUF multiprotein machinery that synthesizes and inserts Fe-S clusters into proteins. Specific focus is put on the ABC ATPase SufC, which contributes to building Fe-S clusters, and appeared early on during evolution.
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7.
Transport of Proteins into Mitochondria.
Hansen, KG, Herrmann, JM
The protein journal. 2019;(3):330-342
Abstract
Mitochondria are essential organelles of eukaryotic cells. They consist of hundreds of different proteins that exhibit crucial activities in respiration, catabolic metabolism and the synthesis of amino acids, lipids, heme and iron-sulfur clusters. With the exception of a handful of hydrophobic mitochondrially encoded membrane proteins, all these proteins are synthesized on cytosolic ribosomes, targeted to receptors on the mitochondrial surface, and transported across or inserted into the outer and inner mitochondrial membrane before they are folded and assembled into their final native structure. This review article provides a comprehensive overview of the mechanisms and components of the mitochondrial protein import systems with a particular focus on recent developments in the field.
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8.
Hsp74/14-3-3σ Complex Mediates Centrosome Amplification by High Glucose, Insulin, and Palmitic Acid.
Lu, YC, Wang, P, Wu, QG, Zhang, RK, Kong, A, Li, YF, Lee, SC
Proteomics. 2019;(7):e1800197
Abstract
It has been reported recently that type 2 diabetes promotes centrosome amplification via 14-3-3σ/ROCK1 complex. In the present study, 14-3-3σ interacting proteins are characterized and their roles in the centrosome amplification by high glucose, insulin, and palmitic acid are investigated. Co-immunoprecipitation in combination with MS analysis identified 134 proteins that interact with 14-3-3σ, which include heat shock 70 kDa protein 4 (Hsp74). Gene ontology analyses reveal that many of them are enriched in binding activity. Kyoto Encyclopedia of Genes and Genomes analysis shows that the top three enriched pathways are ribosome, carbon metabolism, and biosynthesis of amino acids. Molecular and functional investigations show that the high glucose, insulin, and palmitic acid increase the expression and binding of 14-3-3σ and Hsp74 as well as centrosome amplification, all of which are inhibited by knockdown of 14-3-3σ or Hsp74. Moreover, molecular docking analysis shows that the interaction between the 14-3-3σ and the Hsp74 is mainly through hydrophobic contacts and a lesser degree ionic interactions and hydrogen bond by different amino acids residues. In conclusion, the results suggest that the experimental treatment triggers centrosome amplification via upregulations of expression and binding of 14-3-3σ and Hsp74.
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9.
Effects of dietary intervention and n-3 PUFA supplementation on markers of gut-related inflammation and their association with cardiovascular events in a high-risk population.
Awoyemi, A, Trøseid, M, Arnesen, H, Solheim, S, Seljeflot, I
Atherosclerosis. 2019;:53-59
Abstract
BACKGROUND & AIMS Dysbiosis of the gut microbiota is associated with increased levels of circulating lipopolysaccharide (LPS) and subsequent activation of systemic inflammation. Diet is an important modulator of the gut microbiome. We aimed to investigate whether circulating markers of gut-related inflammation, LPS binding protein (LBP) and soluble CD14 (sCD14) can be modulated by n-3 PUFA supplementation and/or diet counselling, and whether these markers are related to cardiovascular (CV) outcome. METHODS 484 men aged 65-75 years, at high CV-risk, were included and randomized in a 2 × 2 factorial design to 36-month intervention with dietary counselling, n-3 PUFA supplementation, or both. N-3 PUFA supplementation was placebo-controlled. ELISAs were used for determination of the biomarkers measured at baseline and study-end. A composite endpoint was defined as new CV-events and CV-mortality after 36 months. RESULTS There were no significant differences in changes of either LBP or sCD14 in the intervention groups compared to their respective controls (n-3 PUFA vs. placebo: p = 0.58, p = 0.15, diet vs. no-diet: p = 0.53, p = 0.59, respectively). The group with LBP levels above median had about 2-fold unadjusted risk of suffering an endpoint compared to the group below (HR 2.22, 95% CI 1.25-3.96; p = 0.01). A similar tendency was seen for sCD14 (HR 1.72, 95% CI 0.97-3.03; p = 0.06). After adjusting for covariates, LBP remained significantly associated with a two-fold CV-risk, whereas sCD14 gained statistical significance, however, lost when hsCRP was added to the model. CONCLUSIONS In our population, markers of gut-related inflammation associated with 36-month CV outcome. However, neither n-3 PUFA nor diet intervention had an effect on these markers.
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10.
Collagen-binding proteins: insights from the Collagen Toolkits.
Farndale, RW
Essays in biochemistry. 2019;(3):337-348
Abstract
The Collagen Toolkits are libraries of 56 and 57 triple-helical synthetic peptides spanning the length of the collagen II and collagen III helices. These have been used in solid-phase binding assays to locate sites where collagen receptors and extracellular matrix components bind to collagens. Truncation and substitution allowed exact binding sites to be identified, and corresponding minimal peptides to be synthesised for use in structural and functional studies. 170 sites where over 30 proteins bind to collagen II have been mapped, providing firm conclusions about the amino acid distribution within such binding sites. Protein binding to collagen II is not random, but displays a periodicity of approximately 28 nm, with several prominent nodes where multiple proteins bind. Notably, the vicinity of the collagenase-cleavage site in Toolkit peptide II-44 is highly promiscuous, binding over 20 different proteins. This may reflect either the diverse chemistry of that locus or its diverse function, together with the interplay between regulatory binding partners. Peptides derived from Toolkit studies have been used to determine atomic level resolution of interactions between collagen and several of its binding partners and are finding practical application in tissue engineering.