Protein functions are often revealed by their localization to specialized cellular sites. Recent reports demonstrated that swiprosin-1 is found together with actin and actin-binding proteins in the ...cytoskeleton fraction of human mast cells and NK-like cells. However, direct evidence of whether swiprosin-1 regulates actin dynamics is currently lacking. We found that swiprosin-1 localizes to microvilli-like membrane protrusions and lamellipodia and exhibits actin-binding activity. Overexpression of swiprosin-1 enhanced lamellipodia formation and cell spreading. In contrast, swiprosin-1 knockdown showed reduced cell spreading and migration. Swiprosin-1 induced actin bundling in the presence of Ca(2+), and deletion of the EF-hand motifs partially reduced bundling activity. Swiprosin-1 dimerized in the presence of Ca(2+) via its coiled-coil domain, and a lysine (Lys)-rich region in the coiled-coil domain was essential for regulation of actin bundling. Consistent with these observations, mutations of the EF-hand motifs and coiled-coil region significantly reduced cell spreading and lamellipodia formation. We provide new evidence of how swiprosin-1 influences cytoskeleton reorganization and cell spreading.
Regulatory dendritic cells (rDCs), which can be induced by mesenchymal stem cells (MSCs), play an important role in inducing and maintaining homeostasis of regulatory T cells and exhibit ...anti-inflammatory functions. In this study, we investigated whether MSCs could differentiate DCs into rDCs and compared the therapeutic effects of rDCs and MSCs on dextran sodium sulfate (DSS)-induced chronic colitis mice.
Immature DCs (imDCs) and lipopolysaccharide (LPS)-treated mature DCs (mDCs) were co-cultured with MSCs for 48 hours, and then the profiles of surface markers and cytokines and regulatory roles of these DCs for primary splenocytes were analyzed. In addition, the therapeutic effects of MSCs and DCs co-cultured with MSCs were compared in chronic colitis mice.
After co-culture of imDCs (MSC-DCs) or LPS-treated mDCs (LPS+MSC-DCs) with MSCs, the expression of CD11c, CD80, CD86, interleukin 6 (IL-6), tumor necrosis factor-α (TNF-α), and interferon-γ (IFN-γ), was decreased, but that of CD11b, IL-10, and transforming growth factor-β (TGF-β) was increased. Furthermore, MSC-DCs and LPS+MSC-DCs induced the expression of CD4, CD25, and Foxp3 in primary splenocytes isolated from mice. In DSS-induced colitis mice, MSCs and MSC-DCs increased colon length, body weight, and survival rate and induced histological improvement. Moreover, in the colon tissues, the expression of IL-6, TNF-α, and IFN-γ decreased, but that of IL-10, TGF-β, and Foxp3 increased in the MSC- and MSC-DC-injected groups.
Our data suggest that MSCs differentiate DCs into rDCs, which ameliorate chronic colitis. Thus, rDCs stimulated by MSCs may be therapeutically useful for the treatment of chronic inflammatory diseases.
The mitochondrial calcium uniporter (MCU) is responsible for mitochondrial calcium uptake and homeostasis. It is also a target for the regulation of cellular anti‐/pro‐apoptosis and necrosis by ...several oncogenes and tumour suppressors. Herein, we report the crystal structure of the MCU N‐terminal domain (NTD) at a resolution of 1.50 Å in a novel fold and the S92A MCU mutant at 2.75 Å resolution; the residue S92 is a predicted CaMKII phosphorylation site. The assembly of the mitochondrial calcium uniporter complex (uniplex) and the interaction with the MCU regulators such as the mitochondrial calcium uptake‐1 and mitochondrial calcium uptake‐2 proteins (MICU1 and MICU2) are not affected by the deletion of MCU NTD. However, the expression of the S92A mutant or a NTD deletion mutant failed to restore mitochondrial Ca2+ uptake in a stable MCU knockdown HeLa cell line and exerted dominant‐negative effects in the wild‐type MCU‐expressing cell line. These results suggest that the NTD of MCU is essential for the modulation of MCU function, although it does not affect the uniplex formation.
Synopsis
This study reports the crystal structures of the N‐terminal domain (NTD) of wild‐type and a S92A mutant form of MCU. Functional analyses suggest that the N‐terminal domain of MCU is essential for the modulation of MCU activity.
Crystal structures of the NTD of WT and a S92A mutant form of MCU were determined.
The structure of MCU NTD contains a novel fold important for post‐translational modifications.
Functional analysis suggests that MCU NTD is essential for the modulation of MCU activity.
This study reports the crystal structures of the N‐terminal domain (NTD) of wild‐type and a S92A mutant form of MCU. Functional analyses suggest that the N‐terminal domain of MCU is essential for the modulation of MCU activity.
Upon invading target cells, multifunctional autoprocessing repeats-in-toxin (MARTX) toxins secreted by bacterial pathogens release their disease-related modularly structured effector domains. ...However, it is unclear how a diverse repertoire of effector domains within these toxins are processed and activated. Here, we report that Makes caterpillars floppy-like effector (MCF)-containing MARTX toxins require ubiquitous ADP-ribosylation factor (ARF) proteins for processing and activation of intermediate effector modules, which localize in different subcellular compartments following limited processing of holo effector modules by the internal cysteine protease. Effector domains structured tandemly with MCF in intermediate modules become disengaged and fully activated by MCF, which aggressively interacts with ARF proteins present at the same location as intermediate modules and is converted allosterically into a catalytically competent protease. MCF-mediated effector processing leads ultimately to severe virulence in mice via an MCF-mediated ARF switching mechanism across subcellular compartments. This work provides insight into how bacteria take advantage of host systems to induce systemic pathogenicity.
In this study, we deal with a Distance-Based Registration with Implicit Registration, which is an enhanced scheme of the Distance-Based Registration in mobile-cellular networks. In comparisons with ...other Location Registration schemes, various studies on the Distance-Based Registration scheme and performance have been performed. However, a real network hierarchy has not been properly reflected in the performance evaluation of the Distance-Based Registration. To accurately evaluate the registration and paging costs of the Distance-Based Registration, a real network hierarchy should reflect that a mobile network is made up of many Visitor Location Register areas. Furthermore, we use an embedded Markov-Chain model in the Visitor Location Register hierarchy, which can reflect not only the Implicit Registration effect of the outgoing calls of user equipment but also cell staying time of the user equipment that may follow a general distribution. Without consideration of the Visitor Location Register, the paging cost decreases due to a small paging area, but the location registration cost rises because of frequent inter Visitor Location Register. The numerical results according to the various conditions show an accurate evaluation of the Distance-Based Registration performance in a real network hierarchy and the general cell staying time. Generally, the total signaling cost will increase when we consider the Visitor Location Register. However, for more appropriate evaluation of the Distance-Based Registration performance, it is necessary to consider the Visitor Location Register hierarchy.
In our continued efforts to find an electrically rechargeable zn/air secondary battery, we report the unique behavior of a zinc oxide anode in the presence of additives such as phosphoric acid, ...tartaric acid, succinic acid and citric acid. These additives were added to the electrolyte, which is an 8.5
M KOH solution containing 25
g of ZnO and 3000
ppm of polyethylene glycol in 1
l of water. In zn/air systems there are two main problems namely the hydrogen overpotential and dendrite formation during recharging. Investigations have studied in detail both of the problems in order to overcome them. The results obtained in presence of additives are compared with the behavior of the electrolyte 8.5
M KOH in the absence of additives. It has been concluded that the hydrogen overpotential is raised enormously while dendrite formation is reduced to some extent. Out of the four acids studied, the order of increase in hydrogen overpotential is: tartaric acid
>
succinic acid
>
phosphoric acid
>
citric acid. The prevention of dendrite formation follows the order: citric acid
>
succinic acid
>
tartaric acid
>
phosphoric acid.
This paper describes the synthesis of eight novel zirconium and hafnium complexes containing N-alkoxy carboxamidate-type ligands, as potential precursors for metal oxides and atomic layer deposition ...(ALD) for HfO2. A series of ligands, viz., N-ethoxy-2,2-dimethylpropanamide (edpaH), N-ethoxy-2-methylpropanamide (empaH), and N-methoxy-2,2-dimethylpropanamide (mdpaH), were used to afford complexes Zr(edpa)4 (1), Hf(edpa)4 (2), Zr(empa)4 (3), Hf(empa)4 (4), Zr(mdpa)4 (5), Hf(mdpa)4 (6), ZrCp(edpa)3 (7), and HfCp(edpa)3 (8). Thermogravimetric analysis curves assessed for the evaporation characteristics of complexes 1–8 revealed single-step weight losses with low residues, except for the mdpa-containing complexes. Single-crystal X-ray diffraction studies of 1, 2, 5, and 6 revealed that all the complexes have monomeric molecular structures, with the central metal ion surrounded by eight oxygen atoms from the four bidentate alkoxyalkoxide ligands. Among the complexes prepared, 8 exhibited a low melting point (64 °C), good volatility (1 Torr at 112 °C), high thermal stability, and excellent endurance over 6 weeks at 120 °C. Therefore, an ALD process for the growth of HfO2 was developed using HfCp(edpa)3 (8) as a novel precursor. Furthermore, the HfO2 film exhibited a low capacitance equivalent oxide thickness of ∼1.5 nm, with J g as low as ∼3 × 10–4 A/cm2 at V g −1 V in a metal–insulator–semiconductor capacitor (Au/HfO2/p-Si).
CHARGE syndrome and Kallmann syndrome (KS) are two distinct developmental disorders sharing overlapping features of impaired olfaction and hypogonadism. KS is a genetically heterogeneous disorder ...consisting of idiopathic hypogonadotropic hypogonadism (IHH) and anosmia, and is most commonly due to
KAL1 or
FGFR1 mutations. CHARGE syndrome, a multisystem autosomal-dominant disorder, is caused by
CHD7 mutations. We hypothesized that
CHD7 would be involved in the pathogenesis of IHH and KS (IHH/KS) without the CHARGE phenotype and that IHH/KS represents a milder allelic variant of CHARGE syndrome. Mutation screening of the 37 protein-coding exons of
CHD7 was performed in 101 IHH/KS patients without a CHARGE phenotype. In an additional 96 IHH/KS patients, exons 6–10, encoding the conserved chromodomains, were sequenced. RT-PCR, SIFT, protein-structure analysis, and in situ hybridization were performed for additional supportive evidence. Seven heterozygous mutations, two splice and five missense, which were absent in ≥ 180 controls, were identified in three sporadic KS and four sporadic normosmic IHH patients. Three mutations affect chromodomains critical for proper CHD7 function in chromatin remodeling and transcriptional regulation, whereas the other four affect conserved residues, suggesting that they are deleterious. CHD7's role is further corroborated by specific expression in IHH/KS-relevant tissues and appropriate developmental expression. Sporadic
CHD7 mutations occur in 6% of IHH/KS patients. CHD7 represents the first identified chromatin-remodeling protein with a role in human puberty and the second gene to cause both normosmic IHH and KS in humans. Our findings indicate that both normosmic IHH and KS are mild allelic variants of CHARGE syndrome and are caused by
CHD7 mutations.
Background & Aims Further histological subclassification of cirrhosis may be useful because of heterogeneity of severity within cirrhosis. We aimed to determine the relationship between histological ...subclassification and clinical stage of cirrhosis as well as grade of portal hypertension. Methods One hundred-twenty-three biopsy-proven cirrhosis patients, whose clinical stage of cirrhosis and hepatic venous pressure gradient (HVPG) could be estimated, were included in this prospective study. Histology of cirrhosis was blindly subclassified using the Laennec fibrosis scoring system semi-quantitatively without knowledge of the clinical stage or the HVPG results. The Laennec system subclassifies cirrhosis as mild – thin septa, moderate – at least two broad septa, and severe – at least one very broad septum or many minute nodules. Clinical stages were determined by the presence or absence of varices, ascites, and variceal hemorrhage. Biological and laboratory data were also collected. Results Alcohol intake was the most common cause of cirrhosis in this cohort (87, 70.7%). Histology of cirrhosis subclassified using the Laennec scoring system significantly correlated with both the clinical stage of cirrhosis ( p <0.001) and HVPG (mild: 8.1 ± 2.6 mm Hg, moderate: 12.4 ± 3.3 mm Hg, severe: 16.3 ± 4.0 mm Hg, p <0.001). With higher grades of histological subclassification of cirrhosis, increased frequency in both severe portal hypertension (HVPG ⩾12 mm Hg) and episodes of variceal hemorrhage were observed ( p <0.001). Conclusions Histological subclassification of cirrhosis by the Laennec fibrosis scoring system is tightly correlated with both the clinical stage of cirrhosis and grade of portal hypertension. This suggests that cirrhosis should be subclassified into different stages according to its histological severity.
The mitochondrial calcium uniporter (MCU) plays essential roles in mitochondrial calcium homeostasis and regulates cellular functions, such as energy synthesis, cell growth, and development. Thus, ...MCU activity is tightly controlled by its regulators as well as post-translational modification, including phosphorylation by protein kinases such as proline-rich tyrosine kinase 2 (Pyk2) and AMP-activated protein kinase (AMPK). In our in vitro kinase assay, the MCU N-terminal domain (NTD) was phosphorylated by protein kinase C isoforms (PKC
, PKC
, and PKC
) localized in the mitochondrial matrix. In addition, we found the conserved S92 was phosphorylated by the PKC isoforms. To reveal the structural effect of MCU S92 phosphorylation (S92p), we determined crystal structures of the MCU NTD of S92E and D119A mutants and analysed the molecular dynamics simulation of WT and S92p. We observed conformational changes of the conserved loop2-loop4 (L2-L4 loops) in MCU NTD
, NTD
, and NTD
due to the breakage of the S92-D119 hydrogen bond. The results suggest that the phosphorylation of S92 induces conformational changes as well as enhancements of the negative charges at the L2-L4 loops, which may affect the dimerization of two MCU-EMRE tetramers.
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