In vitro inhibition of human influenza A virus replication by chloroquine

Inhibition of the human cytomegalovirus UL97 kinase by maribavir is thought to be responsible for the antiviral activity of this compound. Some mutations that confer resistance to maribavir map to UL97, however additional mutations that also confer resistance to the drug were mapped to UL27. These open reading frames share a low level of homology, yet the function of pUL27 remains unknown. A recombinant virus with a deletion in the UL27 open reading frame was reported previously to exhibit a slight replication deficit, but a more important function in vivo was hypothesized given its homology to the UL97 kinase. The potential for an important function in vivo was investigated by determining if these knockout viruses could replicate in human tissue implanted in SCID mice. None of the AD169 derived viruses replicated well in the implanted thymus/liver tissue, and is consistent with previous observations, although all of the viruses replicated to some degree in retinal tissue implants. Replication of the parent viruses was observed at 7 days post inoculation, whereas no replication was detected with any of the recombinant viruses with deletions in UL27. By day 14, replication was detected in two of the three knockout viruses and in all of the viruses by day 42. These data are consistent with minimal defects observed in cell culture, but are not consistent with an important role for UL27 in vivo. We conclude that UL27 is not required for viral replication in vivo.     

Swapping of pro-sequences between keratinases of Bacillus licheniformis and Bacillus pumilus: altered substrate specificity and thermostability

Pro-sequences were swapped in cis between keratinases from Bacillus licheniformis (Ker BL) and Bacillus pumilus (Ker BP) to construct Ker ProBP-BL and Ker ProBL-BP, respectively. Expression of these keratinases was carried out constitutively by E. coli HB101-pEZZ18 system. They were characterized with respect to their parent enzymes, Ker BL and Ker BP, respectively. Ker ProBP-BL became more thermostable with a t(1/2) of 45 min at 80°C contrary to Ker BL which was not stable beyond 60°C. Similarly, the activity of Ker ProBP-BL on keratin and casein substrate, i.e. K:C ratio increased to 1.2 in comparison to 0.1 for Ker BL. Hydrolysis of insulin B-chain revealed that the cleavage sites increased to six from four in case of Ker ProBP-BL in comparison to Ker BL. However, cleavage sites decreased from seven to four in case of Ker ProBL-BP in comparison to the parent keratinase, Ker BP. Likewise, Ker ProBL-BP revealed altered pH and temperature kinetics with optima at pH 10 and 60°C in comparison to Ker BP which had optima at pH 9 and 70°C. It also cleaved soluble substrates with better efficiency in comparison to Ker BP with K:C ratio of 1.6. Pro-sequence mediated conformational changes were also observed in trans and were almost similar to the features acquired by the chimeras constructed in cis by swapping the pro-sequence region.     

Systematic search for putative new domain families in Mycoplasma gallisepticum genome

Background

Stem cell factor (SCF) receptor c-Kit is recognized as a key signaling molecule, which transduces signals for the proliferation, differentiation and survival of stem cells. Binding of SCF to its receptor triggers transactivation, leading to the recruitment of kinases and phosphatases to the docking platforms of c-Kit catalytic domain. Tyrosine phosphatase-1 (Shp-1) deactivates/attenuates 'Kit' kinase activity. Whereas, Asp816Val mutation in the Kit activation loop transforms kinase domain to a constitutively activated state (switch off-to-on state), in a ligand-independent manner. This phenomenon completely abrogates negative regulation of Shp-1. To predict the possible molecular basis of interaction between c-Kit and Shp-1, we have performed an in silico protein-protein docking study between crystal structure of activated c-Kit (phosphorylated c-Kit) and full length crystal structure of Shp-2, a close structural counterpart of Shp-1.

Findings

Study revealed a stretch of conserved amino acids (Lys818 to Ser821) in the Kit activation domain, which makes decisive H-bonds with N-sh2 and phosphotyrosine binding pocket residues of the phosphatase. These H-bonds may impose an inhibitory steric hindrance to the catalytic domain of c-Kit, there by blocking further interaction of the activation loop molecules with incoming kinases. We have also predicted a phosphotyrosine binding pocket in SH2 domains of Shp-1, which is found to be predominantly closer to a catalytic groove like structure in c-Kit kinase domain.

Conclusions

This study predicts that crucial hydrogen bonding between N-sh2 domain of Shp-1 and Kit activation loop can modulate the negative regulation of c-Kit kinase by Shp-1. Thus, this finding is expected to play a significant role in designing suitable gain-of-function c-Kit mutants for inducing conditional proliferation of hematopoietic stem cells.     

β-Decay and the origin of optical purity

Improving Keszthelyis simple model the evolutionary appearance of concentration difference of enanthiomeric compounds due to their differential decomposition by -rays is investigated taking into account the racemization as well. It is shown that if the difference in the cross sections is very small then the resulting concentration difference will never exceed the statistical fluctuations, while in the case of a sufficiently large difference in the cross sections the concentration difference can overgrow the statistical fluctuations in an evolutionary reasonable period of time. The relative difference of the concentrations, however, will be generally much smaller than that of the cross sections. Therefore some other, amplifying mechanism must be postulated in order to explain the optical purity of living beings.     

Mapping QTLs for morpho-agronomic traits in proso millet (<Emphasis Type="Italic">Panicum miliaceum</Emphasis> L.)

Proso millet (Panicum miliaceum L.) is the cereal crop with the low water requirement and increasingly being used for human consumption. It is the most common rotational crop within wheat-based dryland production systems in the semiarid High Plains of the USA. However, there is no published genetic map for this species, which prevents the identification of quantitative trait loci (QTL). The objectives of the present study were (1) construction of a genetic linkage map and (2) identification of DNA markers linked to QTLs for morpho-agronomic traits. A total of 93 recombinant inbred lines derived from a single F₁ (“Huntsman” × “Minsum”) were genotyped with GBS-SNP markers and phenotyped for nine morpho-agronomic traits in the field during 2013 and 2014 at Scottsbluff and Sidney, NE. IciMapping v.4.0.6.0 was used for constructing a genetic linkage map and mapping QTL. The RILs exhibited significant variation for a wide range of traits, and several traits showed evidence of genotype × environment interactions. A total of 833 GBS-SNP markers formed 18 major and 84 minor linkage groups, whereas 519 markers remained ungrouped. A total of 117 GBS-SNP markers were distributed on the 18 major linkage groups spanning a genome length of 2137 cM of proso millet with an average distance of 18 cM between markers. The length and number of markers in each of the 18 major linkage groups ranged from 54.6 to 236 cM and 4 to 12, respectively. A total of 18 QTLs for eight morpho-agronomic traits were detected on 14 linkage groups, each of which explained 13.2–34.7 % phenotypic variance. DNA markers flanking the QTLs were identified, which will aid in marker-assisted selection of these traits. To our knowledge, this is the first genetic linkage map and QTL mapping in proso millet, which will support further genetic analysis and genomics-assisted genetic improvement of this crop.     

Is Gut Dysbiosis an Epicenter of Parkinson’s Disease?

Once recognized as one of the most esoteric diseases of the central nervous system, Parkinson’s disease (PD) is now deemed to be a chronic illness contributed by the central, autonomic and enteric nervous systems. Most likely, an accumulation of α-synuclein in the central and enteric nervous systems is the key that supports this viewpoint. Constipation, one of the non-motor hallmarks in roughly two-third of PD patients, is regulated by the composition of gut bacteria, which is assumed to set off the enteric α-synuclein accrual. Vagus nerve is suggested to direct the signal for α-synuclein over-expression and accumulation to the brain. While trillions of microorganisms reside in the intestinal tract, only one third of the proportion inhabits evenly in all individuals. Existence of an impaired gut-microbe-brain axis consonant with dysbiosis could be an epicenter of this inexplicable disorder. Any alteration in the structure and function of the gastrointestinal tract owing to exposure of endogenous or exogenous chemicals or toxicants could lead to dysbiosis. However, inconsistency in the symptoms even after exposure to same chemical or toxicant in PD patients emphatically creates a conundrum. While the level of a few specific neurotransmitters and metabolites is influenced by microbes, implication of dysbiosis is still debatable. Nevertheless, the scientific literature is overflowing with the remarkable observations supporting the role of dysbiosis in PD. Lack of specificity to differentially diagnose PD with non-PD or PD-plus syndrome, to identify highly precise drug targets and to develop therapeutic stratagems to encounter the disease on the basis of this approach, causes us to be open-minded about the dysbiosis theory. The article reviews the facts supporting gut dysbiosis as the foremost trigger for PD onset along with disagreements.

     

Oncogenic comparison of human papillomavirus type 58 E7 variants

Human papillomavirus 58 (HPV58) ranks the second or third in East Asian cervical cancers. Current studies on HPV58 are scarce and focus on the prototype. Previously, we identified the three most common circulating HPV58 E7 strains contained amino acid alterations: G41R/G63D (51%), T20I/G63S (22%) and T74A/D76E (14%) respectively. Among them, the T20I/G63S variant (V1) had a stronger epidemiological association with cervical cancer. We therefore suggested that V1 possessed stronger oncogenicity than the other two variants. Here, we performed phenotypic assays to characterize and compare their oncogenicities with HPV58 E7 prototype. Our results showed that overexpression of V1 conferred a higher colony‐forming ability to primary murine epithelial cells than prototype (P < 0.05) and other variants, implicating its higher immortalising potential. Further experiments showed that both V1 and prototype enhanced the anchorage‐independent growth of NIH/3T3 cells (P < 0.001), implicating their stronger transforming power than the two other variants. Moreover, they possessed an increased ability to degrade pRb (P < 0.001), which is a major effector pathway of E7‐driven oncogenesis. Our work represents the first study to compare the oncogenicities of HPV58 E7 prototype and variants. These findings deepened our understanding of HPV58 and might inform clinical screening and follow‐up strategy.     

PAHs and their Carcinogenic Potencies in Diesel Fuel and Diesel Generator Exhaust

The PAH profile was characterized in diesel fuel samples collected from different service stations in Agra (India) by using a gas chromatograph equipped with a flame ionization detector (FID). The low molecular weight PAHs were predominant, ranging from 4.4 × 10² to 1.7 × 10³ mg l^{? 1} in fuel. Exhaust emissions from a diesel generator and a four-stroke engine (Skoda) powered by these fuels were monitored by a stack sampler and quantified for PAHs. The high molecular weight PAHs (DbA+IP, BghiP, and BaP, BbF+BkF) were the dominant PAHs in exhaust emissions. Differences in PAH emission factors for the two engines were found and these differences could be related to the combustion conditions affecting the temperature of flue gas. Emission factors and output/input ratio for individual PAHs suggest that the low molecular weight compounds in the fuel contribute to pyrosynthesis of high molecular weight in exhaust. Unburnt fuel partially contributes to low molecular weight PAHs in exhaust. Further, the relative carcinogenic contributions of each compound in the fuel and exhaust were calculated using the TEF approach. DbA + IP and BaP were significant contributors to the carcinogenicity of the PAH mixture in the exhaust.     

Differential morphometric and micro-morpho-anatomical responses toward types of culture vessels used in micropropagation of Hemidesmus indicus (L.) R. Br.

Plant Cell, Tissue and Organ Culture (PCTOC) - Plantlets of Hemidesmus indicus (L.) R. Br. (Indian sarasaparilla) were developed in vitro in two different types of culture vessels and closure...