NMR and mutational identification of the collagen-binding site of the chaperone Hsp47.

Heat shock protein 47 (Hsp47) acts as a client-specific chaperone for collagen and plays a vital role in collagen maturation and the consequent embryonic development. In addition, this protein can be a potential target for the treatment of fibrosis. Despite its physiological and pathological importance, little is currently known about the collagen-binding mode of Hsp47 from a structural aspect. Here, we describe an NMR study that was conducted to identify the collagen-binding site of Hsp47. We used chicken Hsp47, which has higher solubility than its human counterpart, and applied a selective (15)N-labeling method targeting its tryptophan and histidine residues. Spectral assignments were made based on site-directed mutagenesis of the individual residues. By inspecting the spectral changes that were observed upon interaction with a trimeric collagen peptide and the mutational data, we successfully mapped the collagen-binding site in the B/C β-barrel domain and a nearby loop in a 3D-homology model based upon a serpin fold. This conclusion was confirmed by mutational analysis. Our findings provide a molecular basis for the design of compounds that target the interaction between Hsp47 and procollagen as therapeutics for fibrotic diseases

Shaping of a three-dimensional carnivorous trap through modulation of a planar growth mechanism

Leaves display a remarkable range of forms, from flat sheets with simple outlines to cup-shaped traps. Although much progress has been made in understanding the mechanisms of planar leaf development, it is unclear whether similar or distinctive mechanisms underlie shape transformations during development of more complex curved forms. Here, we use 3D imaging and cellular and clonal analysis, combined with computational modelling, to analyse the development of cup-shaped traps of the carnivorous plant Utricularia gibba. We show that the transformation from a near-spherical form at early developmental stages to an oblate spheroid with a straightened ventral midline in the mature form can be accounted for by spatial variations in rates and orientations of growth. Different hypotheses regarding spatiotemporal control predict distinct patterns of cell shape and size, which were tested experimentally by quantifying cellular and clonal anisotropy. We propose that orientations of growth are specified by a proximodistal polarity field, similar to that hypothesised to account for Arabidopsis leaf development, except that in Utricularia, the field propagates through a highly curved tissue sheet. Independent evidence for the polarity field is provided by the orientation of glandular hairs on the inner surface of the trap. Taken together, our results show that morphogenesis of complex 3D leaf shapes can be accounted for by similar mechanisms to those for planar leaves, suggesting that simple modulations of a common growth framework underlie the shaping of a diverse range of morphologies

Heterologous expression and characterization of CpI, OcpA, and novel serine-type carboxypeptidase OcpB from Aspergillus oryzae

In the genome of Aspergillus oryzae, 12 genes have been predicted to encode serine-type carboxypeptidases. However, the carboxypeptidase activities of the proteins encoded by these genes have not yet been confirmed experimentally. In this study, we have constructed three of these 12 genes overexpressing strains using Aspergillus nidulans and characterized their overproduced recombinant proteins. Of these three genes, one was previously named cpI; the other two have not been reported yet, and hence, we named them ocpA and ocpB. The recombinant proteins released amino acid residues from the C terminus of peptides, and the activity of the enzymes was inhibited by phenylmethylsulfonyl fluoride, indicating the enzymes to be serine-type carboxypeptidases. Recombinant OcpA, OcpB, and CpI were stable at 45°C, 55°C, and 55°C, respectively, at a low pH. The enzymatic properties of recombinant OcpB were different from those of any reported serine-type carboxypeptidase. On the other hand, recombinant OcpA had similar enzymatic properties to A. oryzae carboxypeptidases O1 and O2. The DNA and N-terminal amino acid sequences of carboxypeptidases O1 and O2 from A. oryzae IAM2640 were similar to those of OcpA. Result of transcriptional analysis of ocpA, ocpB, and cpI suggest differences in transcriptional regulation between these genes

Therapeutic effect of hybrid FKO on congenital Mandibular ramus length asymmetric case

Hemifacial microsomia (HM) and Russell–Silver Syndrome are a congenital craniofacialmalformation caused by hypoplasia of anatomical structures deriving from the first and second branchial arches. HM involves absence or insufficiency of facial skeleton, soft tissues,ear, and cranial nerves1）.Under these conditions, orthodontic treatment in combination with surgery has been performed in HM patients after growth. However, in case of congenital facial asymmetry, asymptomatic facial expression becomes severe as a result of only the follow–up observation until the end of the growing period. Recently, the therapeutic approach has included the use of an asymmetrical FKO (hybrid FKO) tostimulate the growth of the affected side and consequently to improve symmetry of the mandible deficiency. This study reports on patients of HM treated with a nonsurgical approach using a hybrid FKO and effectiveness of the treatment

Local thermal expansions and lattice strains in Elinvar and stainless steel alloys

International audienceLocal thermal expansions and lattice strains in the Elinvar alloy Fe49.66Ni42.38Cr5.49Ti2.47 (Ni Span C) and the stainless steel SUS304 Fe71.98Ni9.07Cr18.09Mn0.86 (AISI304) were investigated by the temperature-dependent Cr, Fe, and Ni K-edge extended x-ray absorption fine-structure (EXAFS) measurements, combined with the path-integral effective classical potential Monte Carlo (PIECP MC) theoretical simulations. From the EXAFS analysis of the Elinvar alloy, the local thermal expansion around Fe is found to be considerably smaller than the ones around Ni and Cr. This observation can be understood simply because Fe in the Elinvar alloy exhibit an incomplete Invar-like effect. Moreover, in both the Elinvar and SUS304 alloys, the local thermal expansions and the lattice strains around Cr are found to be larger than those around Fe and Ni. From the PIECP MC simulations of both the alloys, the first-nearest neighbor Cr-Fe pair shows extraordinarily large thermal expansion, while the Cr-Cr pair exhibits quite small or even negative thermal expansion. These findings consequently indicate that the lattice strains in both the Elinvar and SUS304 alloys are concentrated predominantly on the Cr atoms. Although the role of Cr in stainless steel has been known to inhibit corrosion by the formation of surface chromium oxide, the present investigation may interestingly suggest that the Cr atoms in the bulk play a hidden new role of absorbing inevitable lattice strains in the alloys

Anther culture in rice proportionally rescues microspores according to gametophytic gene effect and enhances genetic study of hybrid sterility

BackgroundTo investigate plant hybrid sterility, we studied interspecific hybrids of two cultivated rice species, Asian rice (Oryza sativa) and African rice (O. glaberrima). Male gametes of these hybrids display complete sterility owing to a dozen of hybrid sterility loci, termed HS loci, but this complicated genetic system remains poorly understood.ResultsMicrospores from these interspecific hybrids form sterile pollen but are viable at the immature stage. Application of the anther culture (AC) method caused these immature microspores to induce callus. The segregation distortion of 11 among 13 known HS loci was assessed in the callus population. Using many individual calli, fine mapping of the HS loci was attempted based on heterozygotes produced from chromosome segment substitution lines (CSSLs). Transmission ratio distortion (TRD) from microspores was detected at 6 of 11 HS loci in the callus population. The fine mapping of S-1 and S-19 loci using CSSLs revealed precise distances of markers from the positions of HS loci exhibiting excessive TRD.ConclusionsWe demonstrated that AC to generate callus populations derived from immature microspores is a useful methodology for genetic study. The callus population facilitated detection of TRD at multiple HS loci and dramatically shortened the process for mapping hybrid sterility genes

A case of pericarditis in a middle‐aged woman with COVID‐19

Abstract The frequency of pericarditis as a complication in COVID‐19 patients without underlying disease is not well known. We report a case of COVID‐19 presenting with pericarditis without myocarditis or severe respiratory symptoms in a middle‐aged woman, who had neither underlying disease nor previous diagnosis of COVID‐19