Isolation and Biosynthesis of an Azoxyalkene Compound Produced by a Multiple Gene Disruptant of Streptomyces rochei

Streptomyces rochei 7434AN4 predominantly produces lankacidin and lankamycin under normal culture conditions, suggesting that other biosynthetic gene clusters for secondary metabolites are silent. To exploit silent metabolites of strain 7434AN4, we constructed mutant KA57, a multiple disruptant of the transcriptional repressor gene srrB together with the biosynthesis genes for both antibiotics. Mutant KA57 accumulated a compound (KA57-A) with a strong UV absorption at 235 nm, which was not detected in the parent strain or other mutants. Various spectroscopic analyses revealed that KA57-A is an azoxyalkene compound of a molecular formula of C10H20N2O3 with the R configuration at C-2. Biosynthesis of KA57-A was also studied by feeding with labeled acetates, amino acids, and 1-hexylamine. The hexenyl moiety (C1’-C6’) was derived from fatty acid, while the 3-amino-butan-1,2-diol moiety (C1-C4) was derived from C-2 of acetate (C1) and serine (C2-C4). Incorporation of [1,1-2H2]1-hexylamine indicated that C1’-C2’ dehydrogenation occurs at the final step of biosynthesis.アクセプト後にアブストラクト等変更あり。This work was supported by a Grants‐in‐Aid for Scientific Research on Innovative Areas from the Ministry of Education, Culture, Sports, Science and Technology of Japan (MEXT), and a Noda Institute for Scientific Research Grant.Supporting information for this articleis available on the WWW under http://dx.doi.org/10.1002/cbic.201500393

Dram1 regulates DNA damage-induced alternative autophagy

Autophagy is an evolutionarily conserved process that degrades subcellular constituents. Mammalian cells undergo two types of autophagy; Atg5-dependent conventional autophagy and Atg5-independent alternative autophagy, and the molecules required for the latter type of autophagy are largely unknown. In this study, we analyzed the molecular mechanisms of genotoxic stress-induced alternative autophagy, and identified the essential role of p53 and damage-regulated autophagy modulator (Dram1). Dram1 was sufficient to induce alternative autophagy. In the mechanism of alternative autophagy, Dram1 functions in the closure of isolation membranes downstream of p53. These findings indicate that Dram1 plays a pivotal role in genotoxic stress-induced alternative autophagy

Long-term efficacy of bevacizumab and irinotecan in recurrent pediatric glioblastoma.

A 5-year-old boy with glioblastoma relapsed soon after postoperative irradiation in combination with temozolomide. Second-line chemotherapy was also ineffective; therefore, the bevacizumab and irinotecan were given after a third gross-total resection of the tumor. Treatment was interrupted for 1 month due to development of posterior reversible encephalopathy syndrome, but was re-initiated at a lower dose of bevacizumab with prolonged intervals between treatments. The patient was alive and disease free 2 years after initial diagnosis. Bevacizumab and irinotecan are a promising regimen for pediatric cases of recurrent glioblastoma after gross-total resection, although the optimal treatment schedule must be determined on a patient-by-patient basis

Autophagy controls centrosome number by degrading Cep63

Centrosome number is associated with the chromosome segregation and genomic stability. The ubiquitin–proteasome system is considered to be the main regulator of centrosome number. However, here we show that autophagy also regulates the number of centrosomes. Autophagy-deficient cells carry extra centrosomes. The autophagic regulation of centrosome number is dependent on a centrosomal protein of 63 (Cep63) given that cells lacking autophagy contain multiple Cep63 dots that are engulfed and digested by autophagy in wild-type cells, and that the upregulation of Cep63 increases centrosome number. Cep63 is recruited to autophagosomes via interaction with p62, a molecule crucial for selective autophagy. In vivo, hematopoietic cells from autophagy-deficient and p62−/− mice also contained multiple centrosomes. These results indicate that autophagy controls centrosome number by degrading Cep63

BNIP3 and NIX Mediate Mieap-Induced Accumulation of Lysosomal Proteins within Mitochondria

Mieap, a p53-inducible protein, controls mitochondrial quality by repairing unhealthy mitochondria. During repair, Mieap induces the accumulation of intramitochondrial lysosomal proteins (designated MALM for Mieap-induced accumulation of lysosome-like organelles within mitochondria) by interacting with NIX, leading to the elimination of oxidized mitochondrial proteins. Here, we report that an additional mitochondrial outer membrane protein, BNIP3, is also involved in MALM. BNIP3 interacts with Mieap in a reactive oxygen species (ROS)-dependent manner via the BH3 domain of BNIP3 and the coiled-coil domains of Mieap. The knockdown of endogenous BNIP3 expression severely inhibited MALM. Although the overexpression of either BNIP3 or NIX did not cause a remarkable change in the mitochondrial membrane potential (MMP), the co-expression of all three exogenous proteins, Mieap, BNIP3 and NIX, caused a dramatic reduction in MMP, implying that the physical interaction of Mieap, BNIP3 and NIX at the mitochondrial outer membrane may regulate the opening of a pore in the mitochondrial double membrane. This effect was not related to cell death. These results suggest that two mitochondrial outer membrane proteins, BNIP3 and NIX, mediate MALM in order to maintain mitochondrial integrity. The physical interaction of Mieap, BNIP3 and NIX at the mitochondrial outer membrane may play a critical role in the translocation of lysosomal proteins from the cytoplasm to the mitochondrial matrix

Clinical application of removable partial dentures using thermoplastic resin—Part I: Definition and indication of non-metal clasp dentures

AbstractThis position paper proposes a definition and naming standard for removable partial dentures (RPDs) using thermoplastic resin, and presents a guideline for clinical application. A panel of 14 experts having broad experience with clinical application of RPDs using thermoplastic resin was selected from members of the Japan Prosthodontic Society. At a meeting of the panel, “non-metal clasp denture” was referred as the generic name of RPDs with retentive elements (resin clasps) made of thermoplastic resin. The panel classified non-metal clasp dentures into two types: one with a flexible structure that lacks a metal framework and the other having a rigid structure that includes a metal framework. According to current prosthetic principles, flexible non-metal clasp dentures are not recommended as definitive dentures, except for limited cases such as patients with a metal allergy. Rigid non-metal clasp dentures are recommended in cases where patients will not accept metal clasps for esthetic reasons. Non-metal clasp dentures should follow the same design principles as conventional RPDs using metal clasps

The genome sequence of Streptomyces rochei 7434AN4, which carries a linear chromosome and three characteristic linear plasmids

Streptomyces rochei 7434AN4 produces two structurally unrelated polyketide antibiotics, lankacidin and lankamycin, and carries three linear plasmids, pSLA2-L (211 kb), -M (113 kb), and -S (18 kb), whose nucleotide sequences were previously reported. The complete nucleotide sequence of the S. rochei chromosome has now been determined using the long-read PacBio RS-II sequencing together with short-read Illumina Genome Analyzer IIx sequencing and Roche 454 pyrosequencing techniques. The assembled sequence revealed an 8,364,802-bp linear chromosome with a high G + C content of 71.7% and 7,568 protein-coding ORFs. Thus, the gross genome size of S. rochei 7434AN4 was confirmed to be 8,706,406 bp including the three linear plasmids. Consistent with our previous study, a tap-tpg gene pair, which is essential for the maintenance of a linear topology of Streptomyces genomes, was not found on the chromosome. Remarkably, the S. rochei chromosome contains seven ribosomal RNA (rrn) operons (16S-23S-5S), although Streptomyces species generally contain six rrn operons. Based on 2ndFind and antiSMASH platforms, the S. rochei chromosome harbors at least 35 secondary metabolite biosynthetic gene clusters, including those for the 28-membered polyene macrolide pentamycin and the azoxyalkene compound KA57-A.This work was supported by Grants-in-Aid for Scientific Research on Innovative Areas (23108515, 25108718 and 17H05446 to K.A.) from Ministry of Education, Culture, Sports, Science and Technology of Japan (MEXT), Grants-in-Aid for Scientific Research (B) (16H04917 to K.A.) from the Japan Society for the Promotion of Science (JSPS), and the Sasakawa Scientific Research Grant from the Japan Science Society to Y.N. This work was partly supported by a JSPS A3 Foresight Program. A.A.F. and R.M. were supported by the Indonesia Endowment Fund for Education (LPDP). Sequencing analysis using an Illumina GAIIx sequencer was supported by the Grant in Aid for Scientific Research on Innovative Areas (22108010 to J.I.) from MEXT

KaPPA-View4: a metabolic pathway database for representation and analysis of correlation networks of gene co-expression and metabolite co-accumulation and omics data

Correlations of gene-to-gene co-expression and metabolite-to-metabolite co-accumulation calculated from large amounts of transcriptome and metabolome data are useful for uncovering unknown functions of genes, functional diversities of gene family members and regulatory mechanisms of metabolic pathway flows. Many databases and tools are available to interpret quantitative transcriptome and metabolome data, but there are only limited ones that connect correlation data to biological knowledge and can be utilized to find biological significance of it. We report here a new metabolic pathway database, KaPPA-View4 (http://kpv.kazusa.or.jp/kpv4/), which is able to overlay gene-to-gene and/or metabolite-to-metabolite relationships as curves on a metabolic pathway map, or on a combination of up to four maps. This representation would help to discover, for example, novel functions of a transcription factor that regulates genes on a metabolic pathway. Pathway maps of the Kyoto Encyclopedia of Genes and Genomes (KEGG) and maps generated from their gene classifications are available at KaPPA-View4 KEGG version (http://kpv.kazusa.or.jp/kpv4-kegg/). At present, gene co-expression data from the databases ATTED-II, COXPRESdb, CoP and MiBASE for human, mouse, rat, Arabidopsis, rice, tomato and other plants are available

Possible Existence of Lysosome-Like Organella within Mitochondria and Its Role in Mitochondrial Quality Control

The accumulation of unhealthy mitochondria results in mitochondrial dysfunction, which has been implicated in aging, cancer, and a variety of degenerative diseases. However, the mechanism by which mitochondrial quality is regulated remains unclear. Here, we show that Mieap, a novel p53-inducible protein, induces intramitochondrial lysosome-like organella that plays a critical role in mitochondrial quality control. Mieap expression is directly regulated by p53 and is frequently lost in human cancer as result of DNA methylation. Mieap dramatically induces the accumulation of lysosomal proteins within mitochondria and mitochondrial acidic condition without destroying the mitochondrial structure (designated MALM, for Mieap-induced accumulation of lysosome-like organelles within mitochondria) in response to mitochondrial damage. MALM was not related to canonical autophagy. MALM is involved in the degradation of oxidized mitochondrial proteins, leading to increased ATP synthesis and decreased reactive oxygen species generation. These results suggest that Mieap induces intramitochondrial lysosome-like organella that plays a critical role in mitochondrial quality control by eliminating oxidized mitochondrial proteins. Cancer cells might accumulate unhealthy mitochondria due to p53 mutations and/or Mieap methylation, representing a potential cause of the Warburg effect

Clinical application of removable partial dentures using thermoplastic resin. Part II: Material properties and clinical features of non-metal clasp dentures

This position paper reviews physical and mechanical properties of thermoplastic resin usedfor non-metal clasp dentures, and describes feature of each thermoplastic resin in clinicalapplication of non-metal clasp dentures and complications based on clinical experience ofexpert panels. Since products of thermoplastic resin have great variability in physical andmechanical properties, clinicians should utilize them with careful consideration of thespecific properties of each product. In general, thermoplastic resin has lower color-stabilityand higher risk for fracture than polymethyl methacrylate. Additionally, the surface ofthermoplastic resin becomes roughened more easily than polymethyl methacrylate. Studiesrelated to material properties of thermoplastic resin, treatment efficacy and follow-up areinsufficient to provide definitive conclusions at this time. Therefore, this position papershould be revised based on future studies and a clinical guideline should be provided