Defective in cuticular ridges (DCR) of Arabidopsis thaliana, a gene associated with surface cutin formation, encodes a soluble diacylglycerol acyltransferase

A key step in the triacylglycerol (TAG) biosynthetic pathway is the final acylation of diacylglycerol (DAG) by DAG acyltransferase. In silico analysis has revealed that the DCR (defective in cuticular ridges) (At5g23940) gene has a typical HX(4)D acyltransferase motif at the N-terminal end and a lipid binding motif VX(2)GF at the middle of the sequence. To understand the biochemical function, the gene was overexpressed in Escherichia coli, and the purified recombinant protein was found to acylate DAG specifically in an acyl-CoA-dependent manner. Overexpression of At5g23940 in a Saccharomyces cerevisiae quadruple mutant deficient in DAG acyltransferases resulted in TAG accumulation. At5g23940 rescued the growth of this quadruple mutant in the oleate-containing medium, whereas empty vector control did not. Lipid particles were localized in the cytosol of At5g23940-transformed quadruple mutant cells, as observed by oil red O staining. There was an incorporation of 16-hydroxyhexadecanoic acid into TAG in At5g23940-transformed cells of quadruple mutant. Here we report a soluble acyl-CoA-dependent DAG acyltransferase from Arabidopsis thaliana. Taken together, these data suggest that a broad specific DAG acyltransferase may be involved in the cutin as well as in the TAG biosynthesis by supplying hydroxy fatty acid.     

Microbial keratinases and their prospective applications: an overview

Microbial keratinases have become biotechnologically important since they target the hydrolysis of highly rigid, strongly cross-linked structural polypeptide “keratin” recalcitrant to the commonly known proteolytic enzymes trypsin, pepsin and papain. These enzymes are largely produced in the presence of keratinous substrates in the form of hair, feather, wool, nail, horn etc. during their degradation. The complex mechanism of keratinolysis involves cooperative action of sulfitolytic and proteolytic systems. Keratinases are robust enzymes with a wide temperature and pH activity range and are largely serine or metallo proteases. Sequence homologies of keratinases indicate their relatedness to subtilisin family of serine proteases. They stand out among proteases since they attack the keratin residues and hence find application in developing cost-effective feather by-products for feed and fertilizers. Their application can also be extended to detergent and leather industries where they serve as specialty enzymes. Besides, they also find application in wool and silk cleaning; in the leather industry, better dehairing potential of these enzymes has led to the development of greener hair-saving dehairing technology and personal care products. Further, their prospective application in the challenging field of prion degradation would revolutionize the protease world in the near future.     

Secretory factors of human neuroblastoma (IMR-32) and human glioblastoma (U87MG) cell lines induce neurite outgrowths in PC12 cells

Neurite outgrowth is essential for the communication of the nervous system. The rat Pheochromocytoma (PC12) cells are commonly used in the neuronal cell study. It is well known that exogenous stimuli such as Nerve Growth Factor (NGF) induce neurite outgrowth. In the present study it has been investigated whether or not the conditioned medium from human neuroblastoma cell line (IMR-32) and human glioblastoma cell line (U87MG) may augment neurite outgrowth in PC12 cells. PC12 were cultured with and without conditioned media of IMR-32 and U87MG. The result showed that both the conditioned media induce neurite outgrowth within 48 hr and stops further proliferation of PC12 cells. However no outgrowth was noted in PC12 cells incubated without conditioned medium. In conclusion, it is shown that both the conditioned media (IMR-32 and U87MG) have the potential to induce the neurite outgrowth in the PC12 cells.     

Changes in protein profile of pigeonpea genotypes in response to NaCl and boron stress

Two pigeonpea [Cajanus cajan (L.) Millsp.] genotypes, a salt tolerant Manak and a salt sensitive ICPL 88039 were subjected to stress treatment of 3 mM boron, 60 mM NaCl and boron + NaCl at the seedling stage. Radicle and plumule proteins were analyzed by SDS-PAGE. Boron treatment increased 28.3 kDa proteins in plumule and 38.3 and 51.9 kDa proteins in radicle of Manak, however, there was no specific protein in ICPL 88039 either in plumule or in radicle. In NaCl treatment 95.6 kDa proteins appeared in plumule and 67.5 kDa proteins in radicle of Manak. Conversely content of some proteins decreased by boron treatment alone or in combination with NaCl although they were present in the controls. Thus, 54.3 kDa protein disappeared in ICPL 88039 plumule, 68.4 kDa in Manak radicle and 28.1 kDa in ICPL 88039 radicle.     

Food availability affects circadian clock-controlled activity and Zugunruhe in the night migratory male blackheaded bunting (Emberiza melanocephala)

This study investigated the functional linkage between food availability and activity behavior in the Palaearctic Indian night migratory blackheaded bunting (Emberiza melanocephala) subjected to artificial light-dark (LD) cycles. Two experiments were performed on photosensitive birds. In the first one, birds were exposed to short days (LD 10/14; Experiment 1A), long days (LD 13/11; Experiment 1B), or increasing daylengths (8 to 13?h light/d; Experiment 1C) and presented with food either for the whole or a restricted duration of the light period. In Experiments 1A and 1B, illumination of the light and dark periods or of the dark period, alone, was changed to assess the influence of the light environment on direct and circadian responses to food cycles. In the second experiment, birds were exposed to LD 12/12 or LD 8/16 with food availability overlapping with the light (light and food presence in phase) or dark period (light and food presence in antiphase). Also, birds were subjected to constant dim light (LL(dim)) to examine the phase of the activity rhythms under synchronizing influence of the food cycles. Similarly, the presentation of food ad libitum (free food; FF) during an experiment examined the effects of the food-restriction regimes on activity rhythms. A continuous measurement of the activity-rest pattern was done to examine both the circadian and direct effects of the food and LD cycles. Measurement of activity at night enabled assessment of the migratory phenotype, premigratory restlessness, or Zugunruhe. The results show that (i) light masked the food effects if they were present together; (ii) birds had a higher anticipatory activity and food intake during restricted feeding conditions; and (iii) food at night alone reduced both the duration and amount of Zugunruhe as compared to food during the day alone. This suggests that food affects both the daily activity and seasonal Zugunruhe, and food cycles act as a synchronizer of circadian rhythms in the absence of dominant natural environmental synchronizers, such as the light-dark cycle.     

Development of a CrN/Cu nanocomposite coating on titanium-modified stainless steel for antibacterial activity against Pseudomonas aeruginosa

A relatively simple method was developed to fabricate CrN/Cu nanocomposite coatings using pulsed DC magnetron sputtering for application in antibacterial activity. These nanocomposite coatings were applied on titanium (Ti)-modified stainless steel substrata (D-9 alloy) and the antibacterial activity of these coating with respect to the Gram-negative bacterium Pseudomonas aeruginosa was investigated qualitatively and quantitatively. Scanning electron microscopy, epifluorescence microscope analyses, and total viable counts confirmed that inclusion of copper in the CrN/Cu nanocomposite coatings provided antibacterial activity against P. aeruginosa. The quantitative examination of the bacterial activity of P. aeruginosa was estimated by the survival ratio as calculated from the number of viable cells which formed colonies on nutrient agar plates.     

Identification of novel SNPs in SYK gene of breast cancer patients: computational analysis of SNPs in the 5′UTR

Spleen tyrosine kinase (SYK) is a non receptor type tyrosine kinase and a known candidate tumor suppressor gene in breast carcinoma. Loss of Syk is associated with breast cancer invasion and increased cell mortality. The main goal of our study was to detect germ-line polymorphisms in SYK gene in breast cancer affected females of Pakistani origin, in order to understand the genetic basis of complex human breast cancer. Seven novel SYK gene SNPs were identified in breast cancer patients. Among these, three were identified in intronic region, one at the 5'splice donor site (5'SD) and three in 5'untranslated region (5'UTR) of SYK gene. Mutations at the 5'SD and at 5'UTR can be crucial and could be responsible for generation of mutated Syk protein. In silico analysis of the 5'UTR variations revealed that one of the mutations was responsible for generation of a more stable structure of 5'UTR. Such a change in pre-mRNA could potentially down regulate SYK expression. These findings add to the growing literature implicating dysfunctional SYK gene as a contributor to human breast cancer, and suggest that therapies targeting its molecular pathways could provide effective means of treating/preventing breast cancer.     

Influence of gibberellin A<Subscript>3</Subscript> application,pH of the medium,photoperiod and temperature on the enhancement of in vitro flowering in <Emphasis Type="Italic">Vitex negundo</Emphasis> L.

Vitex negundo L. is an economically important small medicinal tree and an essential oil is extracted from its flowers. In nature, flowering is season specific and irregular, appearing only after a long vegetative phase. A very much improved protocol has been developed for the enhancement of flowering in vitro, one which increases both the number of flowers and the percentage (98.6%) of micro-plants flowering. The inclusion of gibberellin A₃ (GA₃) in the culture medium played the key role in controlling the in vitro flowering in V. negundo. The promotive effect of GA₃ was further improved by optimising pH, photoperiod and temperature. Our in vitro flower induction procedures provide an extremely effective method for further research on flowering regulation mechanisms in this important medicinal tree.     

Platelets orchestrate remote tissue damage after mesenteric ischemia-reperfusion

Ischemia-reperfusion (I/R) injury is a leading cause of morbidity and mortality. A functional role for platelets in tissue damage after mesenteric I/R is largely unknown. The hypothesis that mesenteric I/R local and remote injury are platelet dependent was tested. Using a murine mesenteric I/R model, we demonstrate that platelets orchestrate remote lung tissue damage that follows mesenteric I/R injury and also contribute, albeit to a lesser degree, to local villi damage. While lung damage is delayed compared with villi damage, it increased over time and was characterized by accumulation of platelets in the pulmonary vasculature early, followed by alveolar capillaries and extravasation into the pulmonary space. Both villi and lung tissues displayed complement deposition. We demonstrate that villi and lung damage are reduced in mice made platelet deficient before I/R injury and that platelet transfusion into previously platelet-depleted mice before I/R increased both villi and lung tissue damage. Increased C3 deposition accompanied platelet sequestration in the lung, which was mostly absent in platelet-depleted mice. In contrast, C3 deposition was only minimally reduced on villi of platelet-depleted mice. Our findings position platelets alongside complement as a significant early upstream component that orchestrates remote lung tissue damage after mesenteric I/R and strongly suggest that reperfusion injury mitigating modalities should consider the contribution of platelets.