Assembly of T-Antigen Double Hexamers on the Simian Virus 40 Core Origin Requires Only a Subset of the Available Binding Sites

Initiation of simian virus 40 (SV40) DNA replication is dependent upon the assembly of two T-antigen (T-ag) hexamers on the SV40 core origin. To further define the oligomerization mechanism, the pentanucleotide requirements for T-ag assembly were investigated. Here, we demonstrate that individual pentanucleotides support hexamer formation, while particular pairs of pentanucleotides suffice for the assembly of T-ag double hexamers. Related studies demonstrate that T-ag double hexamers formed on “active pairs” of pentanucleotides catalyze a set of previously described structural distortions within the core origin. For the four-pentanucleotide-containing wild-type SV40 core origin, footprinting experiments indicate that T-ag double hexamers prefer to bind to pentanucleotides 1 and 3. Collectively, these experiments demonstrate that only two of the four pentanucleotides in the core origin are necessary for T-ag assembly and the induction of structural changes in the core origin. Since all four pentanucleotides in the wild-type origin are necessary for extensive DNA unwinding, we concluded that the second pair of pentanucleotides is required at a step subsequent to the initial assembly process.     

Genome mining revealed polyhydroxybutyrate biosynthesis by Ramlibacter agri sp. nov., isolated from agriculture soil in Korea

A white-colony-forming, facultative anaerobic, motile and Gram-stain-negative bacterium, designated G-1-2-2 ^T was isolated from soil of agriculture field near Kyonggi University, Republic of Korea. Strain G-1-2-2 ^T synthesized the polyhydroxybutyrate and could grow at 10–35 °C. The phylogenetic analysis based on 16S rRNA gene sequence showed that, strain G-1-2-2 ^T formed a lineage within the family Comamonadaceae and clustered as a member of the genus Ramlibacter. The 16S rRNA gene sequence of strain G-1-2-2 ^T showed high sequence similarities with Ramlibacter ginsenosidimutans BXN5-27 ^T (97.9%), Ramlibacter monticola G-3-2 ^T (97.9%) and Ramlibacter alkalitolerans CJ661^T (97.5%). The sole respiratory quinone was ubiquinone-8 (Q-8). The major polar lipids were phosphatidylethanolamine, diphosphatidylglycerol, phosphatidylglycerol, and an unidentified phospholipid. The principal cellular fatty acids were C_16:0, cyclo-C_17:0, summed feature 3 (C_16:1ω7c and/or C_16:1ω6c) and summed feature 8 (C_18:1ω7c and/or C_18:1ω6c). The genome of strain G-1-2-2 ^T was 7,200,642 bp long with 13 contigs, 6,647 protein-coding genes, and DNA G?+?C content of 68.9%. The average nucleotide identity and in silico DNA–DNA hybridization values between strain G-1-2-2 ^T and close members were?≤?81.2 and 24.1%, respectively. The genome of strain G-1-2-2 ^T showed eight putative biosynthetic gene clusters responsible for various secondary metabolites. Genome mining revealed the presence of atoB, atoB2, phaS, phbB, phbC, and bhbD genes in the genome which are responsible for polyhydroxybutyrate biosynthesis. Based on these data, strain G-1-2-2 ^T represents a novel species in the genus Ramlibacter, for which the name Ramlibacter agri sp. nov. is proposed. The type strain is G-1-2-2 ^T (=?KACC 21616 ^T?=?NBRC 114389 ^T).

     

Three new species of the genus Probles F?rster (Hymenoptera,Ichneumonidae, Tersilochinae) from?South Korea

Three closely related species of the genus Probles Förster, P. fulgida sp. n., P. korusa sp. n. and P. rukora sp. n., belong to the subgenus Euporizon Horstmann and differ from other Palearctic species of the genus by a combination of long and apically weakly sinuate ovipositor and short temple. These three species are assigned to a newly designated fulgida species-group, and a portion of the key for identification of this species-group is provided. Based on the shape of the ovipositor apex, the fulgida species-group resemble members of the subgenus Microdiaparsis Horstmann but are distinct in having a much shorter temple.     

The Smartphone Addiction Scale: Development and Validation of a Short Version for Adolescents

Objective

This study was designed to investigate the revised and short version of the smartphone addiction scale and the proof of its validity in adolescents. In addition, it suggested cutting off the values by gender in order to determine smartphone addiction and elaborate the characteristics of smartphone usage in adolescents.

Method

A set of questionnaires were provided to a total of 540 selected participants from April to May of 2013. The participants consisted of 343 boys and 197 girls, and their average age was 14.5 years old. The content validity was performed on a selection of shortened items, while an internal-consistency test was conducted for the verification of its reliability. The concurrent validity was confirmed using SAS, SAPS and KS-scale. Receiver operating characteristics analysis was conducted to suggest cut-off.

Results

The 10 final questions were selected using content validity. The internal consistency and concurrent validity of SAS were verified with a Cronbach''s alpha of 0.911. The SAS-SV was significantly correlated with the SAS, SAPS and KS-scale. The SAS-SV scores of gender (p<.001) and self-evaluation of smartphone addiction (p<.001) showed significant difference. The ROC analysis results showed an area under a curve (AUC) value of 0.963(0.888–1.000), a cut-off value of 31, sensitivity value of 0.867 and specificity value of 0.893 in boys while an AUC value of 0.947(0.887–1.000), a cut-off value of 33, sensitivity value of 0.875, and a specificity value of 0.886 in girls.

Conclusions

The SAS-SV showed good reliability and validity for the assessment of smartphone addiction. The smartphone addiction scale short version, which was developed and validated in this study, could be used efficiently for the evaluation of smartphone addiction in community and research areas.     

Not looking where you are leaping: a novel method of oriented travel in the caterpillar Calindoea trifascialis (Moore) (Lepidoptera: Thyrididae)

The prepupation caterpillar of the Southeast Asian moth Calindoea trifascialis constructs a leaf shelter that jumps across the ground using a jumping method novel among the insects. We found that movement path direction was correlated to the direction opposite to the most intense light. Correlated random walk (CRW) analyses found net squared displacements higher than predicted by a CRW, and fractal dimension analysis indicated straighter paths at large spatial scales. Rearing experiments showed high mortality from predation on the ground, but higher mortality resulted from sun exposure. We interpret jumping path orientation as an efficient search strategy to find shade in a variable landscape, given limited perception, in the presence of overheating and desiccation risks.     

MUC17, a novel membrane-tethered mucin

Membrane mucins have several functions in epithelial cells including cytoprotection, extravasation during metastases, maintenance of luminal structure, and signal transduction. In this paper we describe a large membrane mucin expressed in the normal intestine. This novel mucin, designated MUC17, contains an extended, repetitive extracellular glycosylation domain and a carboxyl terminus with two EGF-like domains, a SEA module domain, a transmembrane domain, and a cytoplasmic domain with potential serine and tyrosine phosphorylation sites. RNA blot analysis and in situ hybridization indicates that MUC17 is expressed in select pancreatic and colon cancer cell lines and in intestinal absorptive cells. Radiation hybrid mapping localized MUC17 to chromosome 7q22 where it resides in close proximity with three other membrane mucin genes, MUC3A, MUC3B, and MUC12. Thus, these membrane mucins reside together in a gene cluster, but are expressed in different tissues and are likely to have different functions as well.     

Surface immobilization of galactose onto aliphatic biodegradable polymers for hepatocyte culture

A novel surface modification method of biodegradable polymers was investigated for inducing the attachment of specific cells onto the polymer surface via ligand-receptor interactions. Galactose, a targeting ligand specific to asialoglycoprotein receptors present on cell membrane of hepatocytes, was introduced on the surface of poly(D,L-lactic-co-glycolic acid) (PLGA) films. A terminal end group of carboxylic acid in PLGA was activated by dicyclohexylcarbodiimide and N-hydroxysuccinimide for the direct conjugation of lactose by reductive amination reaction. Di-block copolymers of PLGA-b-poly(ethylene glycol) (PEG) having a free terminal amine group were also synthesized and used for the conjugation of galactose for the introduction of a PEG spacer between PLGA and galactose. The presence of galactose moieties on the blend film surface was characterized by measuring water contact angle and X-ray photon spectroscopy, and the amount of galactose was indirectly determined by a specific lectin-binding assay. With increasing the galactose concentration on the blend film surface, the initial attachment as well as the cell viability of hepatocyates concomitantly increased. The introduction of PEG spacer reduced the cell attachment and viability. Albumin secretion rate from hepatocytes was enhanced for galactose modified surfaces, whereas it was reduced for the surfaces not having galactose moieties.     

Possible involvement of Hcn1 ion channel in learning and memory dysfunction in SAMP8 mice

The senescence-accelerated mouse prone 8 (SAMP8) strain exhibits age-related learning and memory deficits (LMD) at 2 months of age. Combined linkage analysis of 264 F2 intercross SAMP8 × JF1 mice and RNA-seq analysis identified Hcn1 gene out of 29 genes in the LMD region on chromosome 13. Hcn1 in SAMP8 strain showed 15 times less polyglutamine repetition compared to Japanese fancy mouse 1 (JF1). Whole cell patch clamp analysis showed that Hcn1 ion conductivity was significantly lower in SAMP8 compared to that of JF1, which may be associated with learning and memory deficiency.     

Interacting effects of temperature and density on individual growth performance in a wild population of brown trout

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