The Saccharomyces cerevisiae SPR1 gene encodes a sporulation-specific exo-1,3-beta-glucanase which contributes to ascospore thermoresistance.

A number of genes have been shown to be transcribed specifically during sporulation in Saccharomyces cerevisiae, yet their developmental function is unknown. The SPR1 gene is transcribed during only the late stages of sporulation. We have sequenced the SPR1 gene and found that it has extensive DNA and protein sequence homology to the S. cerevisiae EXG1 gene which encodes an exo-1,3-beta-glucanase expressed during vegetative growth (C. R. Vasquez de Aldana, J. Correa, P. San Segundo, A. Bueno, A. R. Nebrada, E. Mendez, and F. del Ray, Gene 97:173-182, 1991). We show that spr1 mutant cells do not hydrolyze p-nitrophenyl-beta-D-glucoside or laminarin in a whole-cell assay for exo-1,3-beta-glucanases. In addition to the absence of this enzymatic activity, spr1 mutant spores exhibit reduced thermoresistance relative to isogenic wild-type spores. These observations are consistent with the notion that SPR1 encodes a sporulation-specific exo-1,3-beta-glucanase.     

Influence of edaphic and climatic factors on dynamics of root colonization and spore density of vesicular-arbuscular mycorrhizal fungi in Acacia farnesiana Willd. and A. planifrons W.et.A.

 A study was conducted to assess the dynamics of vesicular-arbuscular mycorrhizal (VAM) fungi associated with Acacia farnesiana and A. planifrons in moderately fertile alkaline soils. The intensity of root colonization by VAM fungi and the distribution of VAM fungal structures varied with host species over a period of time. The occurrence of vesicles with varied morphology in the mycorrhizal roots indicates infection by different VAM fungal species. This was further confirmed from the presence of spores belonging to different VAM fungal species in the rhizosphere soils. Root colonization and spore number ranged from 56% – 72% and 5 – 14 g^{–  1}soil in A. farnesiana and from 60% – 73% and 5 – 15 g^{–  1} soil in A. planifrons. Per cent root colonization and VAM spore number in the rhizosphere soil were inversely related to each other in both the Acacia species. However, patterns of the occurrence of VAM fungal structures were erratic. Spores of Acaulospora foveata, Gigaspora albida, Glomus fasciculatum, G. geosporum and Sclerocystis sinuosa were isolated from the rhizosphere of A. farnesiana whereas A. scrobiculata, G. pustulatum, G. fasciculatum, G. geosporum and G. microcarpum were isolated from that of A. planifrons. The response of VAM status to fluctuating edaphic factors varied with host species. In A. farnesiana though soil nitrogen (N) was positively correlated with root colonization, soil moisture, potassium and air temperature were negatively correlated to both root colonization and spore number. Per cent root colonization and spore number in A. planifrons were negatively related to each other. Further, in A. planifrons as the soil phosphorus and N were negatively correlated with the density of VAM fungal spores, the same edaphic factors along with soil moisture negatively influenced root colonization. Received: 16 May 1995 / Accepted: 7 February 1996     

Marine Bacterial Compounds Evaluated by In Silico Studies as Antipsychotic Drugs Against Schizophrenia

Schizophrenia (SCZ) is one of the brain disorders which affects the thinking and behavioral skills of patients. This disorder comes along with an overproduction of kynurenic acid in the cerebrospinal fluid and the prefrontal cortex of SCZ patients. In this study, marine bacterial compounds were screened for their suitability as antagonists against human kynurenine aminotransferase (hKAT-1) which causes the synthesis of kynurenic acid downstream which ultimately causes the SCZ disorder according to the kynurenic hypothesis of SCZ. The marine actinobacterial compound bonactin shows more promising results than other tested marine compounds such as the histamine H2 blocker famotidine and indole-3-acetic acid (IAC) from docking and in silico toxicological studies carried out here. The obtained results of the Grid-based Ligand Docking with Energetics (Glide) scores of extra-precision (XP) Glide against the target protein hKAT-1 on IAC, famotidine, and bonactin were ??6.581, ??6.500 and ??7.730 kcal/mol where Glide energies were ??29.84, ??28.391, and ??47.565 kcal/mol, respectively. Bonactin is known as an antibacterial and antifungal compound being extracted from a marine Streptomyces sp. Comparing tested compounds against the drug target hKAT-1, bonactin alone showed the best Glide score and Glide energy on the target protein hKAT-1.     

Exploring the bioactive potential of <Emphasis Type="Italic">Serriatia marcescens</Emphasis> VITAPI (Acc: 1933637) isolated from soil

BACKGROUND

Serratia is one of the most important groups of bacteria which produces proteolytic enzymes effectively and known to possess anti-inflammatory properties. The main focus of the current study was to extract the enzyme serratiopeptidase and pigment prodigiosin from Serratia mascescens. Prodigiosin is a red colored pigment produced by the bacterium Serratia marcescens. It is emerging as a valuable molecule because of its large applications. It has already been proved that pigmented strain of Serratia marcescens is less virulent than non-pigmented strains. Moreover the strain we have obtained is from farm soil which indicates that prodigiosin production can be carried safely using this strain.

METHODS

In the present study, the isolate VITASP strain was confirmed by morphological, biochemical and molecular studies. The enzyme and pigment were analyzed for anti-oxidant, anti-inflammatory and cytotoxic properties.

RESULTS

The isolate was further confirmed and identified as Serratia marcescens with 99% similarity. The extracted pigment showed potent radical scavenging effect with 86% and the enzyme was found to inhibit 83%, which was significant in comparison to ascorbic acid standard. The in vitro anti-inflammatory effect of pigment in controlled experimental conditions revealed its protection at 88% and the enzyme with 90%. Aspirin was used as the reference drug. The present findings exhibited a concentration dependent inhibition. The cytotoxic bioassay of pigment showed the IC₅₀ value as (50) μg/mL with 63% cytotoxicity which was statistically significant compared to positive control.

CONCLUSION

Therefore, it appears to be an essential remedial and application research. It may turn out to be highly beneficial to mankind in solving many problems associated with human health.

     

The role of ubiquitin-conjugating enzyme Ube2j1 phosphorylation and its degradation by proteasome during endoplasmic stress recovery

The human Ube2j1 and Ube2j2 are the only ubiquitin-conjugating enzymes (E2s) that are localized to endoplasmic reticulum (ER) through its C-terminal transmembrane domains. Ube2j1 is a known substrate of MAPK signalling pathway and it is phosphorylated at serine-184 during ER stress. Here, we demonstrate that Ube2j1, not Ube2j2 is essential for the recovery of cells from transient ER stress. The ectopic expression of wild-type Ube2j1 and phospho-mimic mutant, Ube2j1^S184D but not phospho-mutant Ube2j1^S184A can recover cells from ER stress. We also found that ubiquitin-ligase (E3), c-IAP1 preferentially interacts with phosphorylated Ube2j1. Moreover, we noticed that phosphorylated Ube2j1 is rapidly degraded by the proteasome during ER stress cell recovery. Taken together, these data suggest that Ube2j1 and its phosphorylation is important for transient ER stress cell recovery and the phosphorylated Ube2j1 is degraded by the proteasome.     

Inhibitory effects of voluntary wheel exercise on apoptosis in splenic lymphocyte subsets of C57BL/6 mice.

Two-month-old mice were placed in cages with (Ex) or without exercise running wheels with free access to the wheel 24 h/day for 10 mo. An equal amount of food for both groups was provided daily. Ex mice ran an average of 33.67 km/wk initially, and exercise decreased gradually with age. Ex mice had gained an average of 43.5% less body weight at the end of the experiment. Although serum lipid peroxides were not altered by exercise, superoxide dismutase and glutathione peroxidase activities in serum were significantly increased. Flow cytometric analysis of spleen cells revealed an increased percentage of CD8+ T cells and a decreased percentage of CD19+ B cells in Ex mice (P < 0.05). Exercise decreased apoptosis in total splenocytes and CD4+ cells incubated with medium alone or with H(2)O(2), dexamethasone, tumor necrosis factor-alpha (TNF-alpha), or anti-CD3 monoclonal antibody (P < 0.05) and CD8+ cells with medium alone or with TNF-alpha (P < 0.05). Even though exercise did not alter the intracellular cytokines (TNF-alpha and interleukin-2) or Fas ligand, it did significantly lower interferon-gamma in CD4+ and CD8+ cells (P < 0.05). In summary, voluntary wheel exercise appears to decrease H(2)O(2)-induced apoptosis in immune cells as well as decrease interferon-gamma production.     

Regeneration of plants from primary leaves of cowpea

Plants were regenerated from the in vitro cultured explants of primary leaves of cowpea (Vigna unguiculata L. Walp). Primary leaves, including the intact petiole, were excised from three-day-old seedlings and cultured on Gamborg's B5 basal medium containing 8×10^–7 M 2,4,5-trichlorophenoxyacetic acid, 1×10^–2 M L-glutamine and 1×10^–4 M adenine sulfate. Callus formed at the petiole end. Prolific shoot regeneration occurred when this callus was transferred to B5 basal medium containing 5×10^–6 M 6-benzyl-aminopurine (BAP). Regenerated shoots rooted in growth-regulator-free B5 basal medium and were established in soil.Abbreviations BAP 6-benzylaminopurine - IAA indole-3-acetic acid - NAA 1-napthalene acetic acid - 2,4,5-T 2,4,5-trichloro-phenoxyacetic acid     

Amino sugars in the glycoprotein toxin from Bacillus thuringiensis subsp. israelensis.

The carbohydrate content of purified Bacillus thuriniensis subsp. israelensis crystal toxin was determined by six biochemical tests, column chromatography on an amino acid analyzer, and the binding of 11 fluorescent lectins. The crystals contained approximately 1.0% neutral sugars and 1.7% amino sugars. The amino sugars consisted of 70% glucosamine and 30% galactosamine. No N-acetylneuraminic acid (sialic acid) was detected. The presence of amino sugars was confirmed by the strong binding of fluorescent wheat germ agglutinin and the weak binding of fluorescent soybean agglutinin. These lectins recognize N-acetyl-D-glucosamine and N-acetyl-D-galactosamine, respectively. The lectin-binding sites appeared evenly distributed among the protein subunits of the crystal. The sugars were covalently attached to the crystal toxin because wheat germ agglutinin still bound alkali-solubilized toxin which had been boiled in sodium dodecyl sulfate, separate by polyacrylamide gel electrophoresis, and transferred to nitrocellulose membranes. This study demonstrates the covalent attachment of amino sugars and indicates that the B. thuringiensis subsp. israelensis protein toxins should be viewed as glycoprotein toxins. The crystals used in the present study were purified on sodium bromide density gradients. Studies employing crystals purified on Renografin density gradients can give artificially high values for the anthrone test for neutral sugars.     

Antimicrobial activity of medicinal plants and induction of defense related compounds in banana fruits cv. Robusta against crown rot pathogens

A total of 72 plant extracts were tested in vitro for their ability to inhibit the mycelial growth of Lasiodiplodia theobromae and Colletotrichum musae the causal agents of crown rot disease of banana. The results showed that the leaf extract of Zimmu (an interspecific hybrid of Allium cepa L. × Allium sativum L.) and tuber extract of Zehneria scabra recorded maximum inhibition of mycelial growth and spore germination of both the test pathogens. The dipping of banana fruits in Zimmu leaf extract at 25% conc. exhibited 100% inhibition of crown rot disease in cold storage (14 °C) up to 35 days and increased the shelf life to 64 days. However, at room storage (28 ± 2 °C), the same treatment exhibited 86% inhibition of crown rot disease up to 12 days. It was found that the treatment of banana fruits with Zimmu leaf extract did not alter the organoleptic properties of banana. The biochemical analysis of banana fruits treated with Zimmu leaf extract showed significant increase in phenylalanine ammonia-lyase (PAL), chitinase and β-1,3-glucanase activities and enhanced accumulation of phenolic compounds compared to other treatments. These findings suggest that the effect of Zimmu leaf extract on crown rot disease may be associated with the direct fungi toxic property against the test pathogens and elicitation of defense related compounds in banana fruits.