Enhanced growth and nodulation of pigeon pea by co-inoculation of Bacillus strains with Rhizobium spp

Endophytic bacteria which are known to reside in plant tissues have often been shown to promote plant growth. Present study deals with the isolation of putative endophytes from the surface sterilized root nodules of pigeon pea (Cajanus cajan) designated as non-rhizobial (NR) isolates. Three of these non-rhizobial isolates called NR2, NR4 and NR6 showed plant growth promotion with respect to increase in plant fresh weight, chlorophyll content, nodule number and nodule fresh weight when co-inoculated with the rhizobial bioinoculant strain IC3123. The three isolates were neither able to nodulate C. cajan nor did they show significant plant growth promotion when inoculated alone without Rhizobium spp. IC3123. All the three isolates were gram positive rods with NR2 and NR4 showing endospore formation and formed one single cluster in Amplified Ribosomal DNA Restriction Analysis (ARDRA). Partial sequences of 16S rRNA genes of NR4 and NR6 showed 97% similarity to Bacillus megaterium. The Bacillus strains NR4 and NR6 were able to produce siderophores which the rhizobial bioinoculant IC3123 was able to cross-utilize. Under iron starved conditions IC3123 showed enhanced growth in the presence of the Bacillus isolates indicating that siderophore mediated interactions may be underlying mechanism of beneficial effect of the NR isolates on nodulation by IC3123.     

Identification of a consensus site for TRAF6/p62 polyubiquitination

Tumor necrosis factor receptor-associated factor 6 (TRAF6) is an ubiquitin ligase that regulates a diverse array of physiological processes via forming Lys-63 linked polyubiquitin chains. In this study, the lysine selection process for TRAF6/p62 ubiquitination was examined. The protein sequence of two characterized TRAF6/p62 substrates, NRIF and TrkA, revealed a conserved consensus pattern for the ubiquitination site of these two TRAF6 substrates. The consensus pattern established in the verified substrates was common to the other Trk receptor family members, TrkB and TrkC. Interestingly, Lysine 811 in TrkB was selected for ubiquination, and mutation of Lysine 811 diminished the formation of TRAF6/p62 complex that is necessary for effective ubiquination. Moreover, downstream signaling was affected upon binding of BDNF to the mutant TrkB receptor. These findings reveal a possible selection process for targeting a specific lysine residue by a single E3 ligase and underscore the role of the scaffold, p62, in this process.     

Nerve Growth Factor Stimulates Multisite Tyrosine Phosphorylation and Activation of the Atypical Protein Kinase C's via a src Kinase Pathway

Atypical protein kinase C (PKC) isoforms are required for nerve growth factor (NGF)-initiated differentiation of PC12 cells. In the present study, we report that PKC-iota becomes tyrosine phosphorylated in the membrane coincident with activation posttreatment with nerve growth factor. Tyrosine phosphorylation and activation of PKC-iota were inhibited in a dose-dependent manner by both PP2 and K252a, src and TrkA kinase inhibitors. Purified src was observed to phosphorylate and activate PKC-iota in vitro. In PC12 cells deficient in src kinase activity, both NGF-induced tyrosine phosphorylation and activation of PKC-iota were also diminished. Furthermore, we demonstrate activation of src by NGF along with formation of a signal complex including the TrkA receptor, src, and PKC-iota. Recruitment of PKC-iota into the complex was dependent on the tyrosine phosphorylation state of PKC-iota. The association of src and PKC-iota was constitutive but was enhanced by NGF treatment, with the src homology 3 domain interacting with a PXXP sequence within the regulatory domain of PKC-iota (amino acids 98 to 114). Altogether, these findings support a role for src in regulation of PKC-iota. Tyrosine 256, 271, and 325 were identified as major sites phosphorylated by src in the catalytic domain. Y256F and Y271F mutations did not alter src-induced activation of PKC-iota, whereas the Y325F mutation significantly reduced src-induced activation of PKC-iota. The functional relevance of these mutations was tested by determining the ability of each mutant to support TRAF6 activation of NF-kappaB, with significant impairment by the Y325F PKC-iota mutant. Moreover, when the Y352F mutant was expressed in PC12 cells, NGF's ability to promote survival in serum-free media was reduced. In summary, we have identified a novel mechanism for NGF-induced activation of atypical PKC involving tyrosine phosphorylation by c-Src.     

Photoperiodic effect on some enzymes and metabolites in diapausingAntheraea mylitta pupae andPhilosamia ricini larvae during development

The variation in acid phosphatase (EC 3.1.3.2) activity inAntheraea mylitta was similar in all light and dark groups exposed to different photophases (LD =0:24, 24:0, 18:6, 14:10, 10:14 and 12:12 h) maintaining all along a higher activity than its alkaline counterpart. The highest activity was recorded on day 82 in LD group 10:14 h. The non-diapausingPhilosamia ricini larvae registered highest activity in LD group 0:24 h on day 5. Alkaline phosphatase (EC 3.1.3.1) activity was low all through metamorphosis in both the lepidopterans, although significantly elevated activity was observed on day 5 in larvae of allPhilosamia ricini LD regimens and on day 82 inAntherae mylitta. Photoperiodic effect on Phosphorylase (EC 2.3.1.1) activity, glycogen and inorganic phosphates content have also been studied. Exposure to LD 10:14, 14:10 and 18:6 h provoked early diapause termination inAntheraea mylitta. The non-diapausingPhilosamia ricini was unaffected in moth emergence but the emerged adults of LD 24:0 and 0:24 h groups were unhealthy, small and did not mate or oviposit.     

Insect antifeedant and growth regulating activities of neem seed oil – the role of major tetranortriterpenoids

Abstract: An attempt was made to correlate insect antifeedant and growth regulatory activities of neem ( Azadirachta indica ) seed oil with the major tetranortriterpenoids. Selective elimination of triterpenoids by preparative high-performance liquid chromatography, incorporation of the eliminated compounds in defined concentrations and bioassaying the resultant fractions against Spodoptera litura indicated the necessity to quantify major triterpenoids for correlation of bioactivity of neem oil.     

Epitopes recognized by serum anti-α-galactoside antibody are present on brain glycoproteins in man

Naturally occurring serum IgG against terminal α-galactoside epitopes (anti-Gal), present exclusively in man, apes and old world monkeys, was used as probe for these epitopes in human brain. Human brain grey matter soluble glycoproteins enriched inα galactosyl groups by affinity chromatography on jacalin-sepharose, specifically binds to human anti-Gal in immuno dot blots. Anti-Gal recognized exclusively the terminal α galactoside epitope in human brain glycoproteins since binding was abolished by the presence of 1-0-methyl α-D-galactopyranoside as well as by pretreatment of glycoproteins with coffee bean α-galactosidase. Anti-Gal-peroxidase staining of jacalin-binding human brain glycoproteins in western immuno blots revealed mainly five anti-Gal-binding polypeptides withM _r (in kDa) of 94, 108, 180, 210 and 230 respectively. Since the presence of anti-Gal in higher animals accompanies suppression of the corresponding epitope in most tissues, apparently to maintain immunological balance, possible implications of the above observation for autoimmunity, tumor metastasis and infection are discussed.     

Molecular characterization of <Emphasis Type="Italic">bmyC</Emphasis> gene of the mosquito pupicidal bacteria, <Emphasis Type="Italic">Bacillus amyloliquefaciens</Emphasis> (VCRC B483) and in silico analysis of bacillomycin D synthetase C protein

A strain of Bacillus amyloliquefaciens (VCRC B483) exhibiting mosquito pupicidal, keratinase and antimicrobial activities was isolated from mangrove forest ecosystem of Andaman and Nicobar Islands. Molecular characterization of the strain showed the presence of lipopeptide encoding bmyC gene. Phylogenetic tree based on protein sequence of this gene exhibited homology with mycosubtilin synthetase of Bacilus atropheus and Iturin synthetase of Bacillus subtilis and B. amyloliquefaciens. This is the first report on the evolutionary conservation of amino acids concerned with the function and structure of bmyC protein of B. amyloliquefaciens. The presence of valine at the 1197th position in our strain was found to be unique and different from the existing strains of B. subtilis and B. amyloliquefaciens. Molecular modelling studies revealed significant changes in the structure of epimerization domain of the bmyC protein with A1197V variation. Crude metabolite of this strain exhibited antifungal activity against Fusarium sp. and Carvularia sp.     

Intersection of endocytic and exocytic systems in Toxoplasma gondii

Host cytosolic proteins are endocytosed by Toxoplasma gondii and degraded in its lysosome‐like compartment, the vacuolar compartment (VAC), but the dynamics and route of endocytic trafficking remain undefined. Conserved endocytic components and plant‐like features suggest T. gondii endocytic trafficking involves transit through early and late endosome‐like compartments (ELCs) and potentially the trans‐Golgi network (TGN) as in plants. However, exocytic trafficking to regulated secretory organelles, micronemes and rhoptries, also proceeds through ELCs and requires classical endocytic components, including a dynamin‐related protein, DrpB. Here, we show that host cytosolic proteins are endocytosed within 7 minutes post‐invasion, trafficked through ELCs en route to the VAC, and degraded within 30 minutes. We could not definitively interpret if ingested protein is trafficked through the TGN. We also found that parasites ingest material from the host cytosol throughout the parasite cell cycle. Ingested host proteins colocalize with immature microneme proteins, proM2AP and proMIC5, in transit to the micronemes, but not with the immature rhoptry protein proRON4, indicating that endocytic trafficking of ingested protein intersects with exocytic trafficking of microneme proteins. Finally, we show that conditional expression of a DrpB dominant negative mutant increases T. gondii ingestion of host‐derived proteins, suggesting that DrpB is not required for parasite endocytosis.      

Asymmetric distribution of muscarinic acetylcholine receptors in Madin-Darby canine kidney cells

We have characterized the muscarinic AChreceptors (mAChRs) expressed in Madin- Darby canine kidney (MDCK)strain II epithelial cells. Binding studies with themembrane-impermeable antagonist N-[³H]methylscopolaminedemonstrated that mAChRs are ~2.5 times more abundant on thebasolateral than on the apical surface. Apical, but not basolateral,mAChRs inhibited forskolin-stimulated adenylyl cyclase activity inresponse to the agonist carbachol. Neither apical nor basolateralmAChRs exhibited detectable carbachol-stimulated phospholipase Cactivity. Carbachol application to the apical or the basolateralmembrane resulted in a threefold increase in intracellularCa²⁺ concentration, which wascompletely inhibited by pertussis toxin on the apical side andpartially inhibited on the basolateral side. RT-PCR analysis showedthat MDCK cells express the M₄ and M₅ receptor mRNAs. These datasuggest that M₄ receptors reside on the apical and basolateral membranes of polarized MDCK strain IIcells and that the M₅ receptor mayreside in the basolateral membrane of a subset of cells.

     

Relevance of Non-ceruloplasmin Copper to Oxidative Stress in Patients with Hepatocellular Carcinoma

Altered copper homeostasis and oxidative stress have been observed in patients with hepatocellular carcinoma. Non-ceruloplasmin copper, the free form, is a potent pro-oxidant than the protein bound copper. The aim of the present study was to evaluate which form of copper can be correlated with the oxidative stress in the circulation and in the malignant liver tissues of hepatocellular carcinoma patients. Hepatocellular carcinoma patients (grades II and III, n = 18) were enrolled in this study. Serum levels of total, free and bound copper, ceruloplasmin, iron, iron-binding capacity, lipid peroxidation products, and enzymatic and non-enzymatic antioxidants were quantified in serum and in malignant liver tissues and compared with those of normal samples (n = 20). A significant positive correlation between the serum non-ceruloplasmin copper and lipid peroxidation products and negative correlation with antioxidants were observed in hepatocellular carcinoma patients. In liver tissue, glutathione peroxidase, superoxide dismutase, and catalase activity were significantly decreased with concomitant elevation in oxidative stress markers. Our experiment revealed that the elevation in non-ceruloplasmin copper has high relevance with the oxidative stress than the bound copper.