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961.
GRN has been shown to have roles in multiple processes involved in cell growth, development and wound repair in rodents and humans. We have isolated the full-length cDNA of GRN gene encoding porcine granulin protein by in silico cloning, RT-PCR and RACE. The deduced amino acid indicated 71.5% identity with the corresponding human sequence and the seven and one-half granulins showed highly conservative between pig, human and murine. A single nucleotide substitution resulting in the amino acid change (ATG/Met --> TTG/Leu) was detected within exon 5. Allele frequencies in six pig breeds showed distinctive differences between those Chinese indigenous pig breeds and European pigs. Using the IMpRH panel, we mapped the porcine GRN gene to porcine chromosome 12p11-p13. Our data provide basic molecular information useful for the further investigation on the function of GRN gene. 相似文献
962.
963.
Stephen R Hughes Patrick F Dowd Ronald E Hector Tadas Panavas David E Sterner Nasib Qureshi Kenneth M Bischoff Sookie S Bang Jeffrey A Mertens Eric T Johnson Xin-Liang Li John S Jackson Robert J Caughey Steven B Riedmuller Scott Bartolett Siqing Liu Joseph O Rich Philip J Farrelly Tauseef R Butt Joshua Labaer Michael A Cotta 《Journal of peptide science》2008,14(9):1039-1050
New methods of safe biological pest control are required as a result of evolution of insect resistance to current biopesticides. Yeast strains being developed for conversion of cellulosic biomass to ethanol are potential host systems for expression of commercially valuable peptides, such as bioinsecticides, to increase the cost-effectiveness of the process. Spider venom is one of many potential sources of novel insect-specific peptide toxins. Libraries of mutants of the small amphipathic peptide lycotoxin-1 from the wolf spider were produced in high throughput using an automated integrated plasmid-based functional proteomic platform and screened for ability to kill fall armyworms, a significant cause of damage to corn (maize) and other crops in the United States. Using amino acid scanning mutagenesis (AASM) we generated a library of mutagenized lycotoxin-1 open reading frames (ORF) in a novel small ubiquitin-like modifier (SUMO) yeast expression system. The SUMO technology enhanced expression and improved generation of active lycotoxins. The mutants were engineered to be expressed at high level inside the yeast and ingested by the insect before being cleaved to the active form (so-called Trojan horse strategy). These yeast strains expressing mutant toxin ORFs were also carrying the xylose isomerase (XI) gene and were capable of aerobic growth on xylose. Yeast cultures expressing the peptide toxins were prepared and fed to armyworm larvae to identify the mutant toxins with greatest lethality. The most lethal mutations appeared to increase the ability of the toxin alpha-helix to interact with insect cell membranes or to increase its pore-forming ability, leading to cell lysis. The toxin peptides have potential as value-added coproducts to increase the cost-effectiveness of fuel ethanol bioproduction. Copyright (c) 2008 European Peptide Society and John Wiley & Sons, Ltd. 相似文献
964.
Mi Kwon Shozo Fujioka Ji Hyun Jeon Ho Bang Kim Suguru Takatsuto Shigeo Yoshida Chung Sun An Sunghwa Choe 《Journal of Plant Biology》2005,48(2):237-244
Brassinosteroid (BR)-6-oxidases mediate the bridge reactions that connect the late and early C-6 oxidation pathways by converting
6-deoxoBR to 6-oxoBRs. Two similar genes ofArabidopsis, CYP85A1 (At5g38970) andCYP85A2 (At3g30180), are proposed to encode BR-6-oxidases based on findings that heterologously expressed genes mediate BR-6-oxidation
reactions in yeast. However, genetic evidence that both genes are critically involved in the BR-6-oxidation step inArabidopsis has been limited. Here, we show that a double mutant for the two genes displays dwarfism similar to that of typical BR biosynthesis-deficient
mutants, suggesting that they are the major BR-6-oxidases inArabidopsis. Examination of endogenous BR levels and metabolism monitoring tests using this double mutant revealed a great reduction
in the levels of 6-oxoBRs, e.g., TY and CS, due to a lack in the conversion reactions from 6-deoxoCS to CS, and from 6-deoxoTY
to TY. Surprisingly, the double mutant accumulated a significant amount of 6-oxocampestanol, suggesting that the upstream
C-6 oxidation of campestanol to 6-oxocampestanol is not catalyzed by the two BR-6-oxidases inArabidopsis, rather, by another enzyme yet to be discovered. 相似文献
965.
Yaw Joo Kim Ho Bang Kim Eun Hye Baek Sunggi Heu Chung Sun An 《Journal of Plant Biology》2005,48(1):39-46
Plant chitinases have been known as pathogenesis-related (PR) proteins, but recent studies suggest that they play functional
roles during normal plant growth and development. We previously isolated two cDNA clones encoding endochitinases,EuNOD-CHT1 and -CHT2, from the root nodules ofElaeagnus umbellata. These genes show differential expression patterns, with theEuNOD-CHT1 gene being active in the root nodules and meristems, whileEuNOD-CHT2 is preferentially expressed in the infected cells of those nodules. To elucidate the functional roles of these two endochitinases,
we have now constitutively expressed each gene in a heterologous plant system,Arabidopsis thaliana. Stable inheritance and expression of the transgenes were confirmed by genomic Southern hybridization and RT-PCR. Our transgenic
plants did not differ morphologically from the wild types. However, constitutive expression ofEuNOD-CHT1 and -CHT2 inArabidopsis resulted in increased resistance against a fungal pathogen,Botrytis cinerea, but not against a bacterial agent,Pseudomonas syringae pv. Tomato DC3000. Expression levels were enhanced by both wounding and jasmonic acid treatments (forEuNOD-CHT1), or by jasmonic acid only (forEuNOD-CHT2). These data suggest thatEuNOD-CHT1 and -CHT2 primarily play defensive roles during root nodule development inE. umbellata. 相似文献
966.
Plant peroxidases (POD) reduce hydrogen peroxide (H2O2) in the presence of an electron donor. Extracellular POD can also induce H2O2 production and may perform a significant function in responses to environmental stresses via the regulation of H2O2 in plants. We previously described the isolation of 10 POD cDNA clones from cell cultures of sweetpotato (Ipomoea batatas). Among them, the expression of the swpa4 gene was profoundly induced by a variety of abiotic stresses and pathogenic infections (Park et al. in Mol Gen Genome 269:542–552
2003; Jang et al. in Plant Physiol Biochem 42:451–455 2004). In the present study, transgenic tobacco (Nicotiana tabacum) plants overexpressing the swpa4 gene under the control of the CaMV 35S promoter were generated in order to assess the function of swpa4
in planta. The transgenic plants exhibited an approximately 50-fold higher POD specific activity than was observed in control plants.
Both transient expression analysis with the swpa4-GFP fusion protein and POD activity assays in the apoplastic washing fluid
revealed that the swpa4 protein is secreted into the apoplastic space. In addition, a significantly enhanced tolerance to
a variety of abiotic and biotic stresses occurred in the transgenic plants. These plants harbored increased lignin and phenolic
content, and H2O2 was also generated under normal conditions. Furthermore, they showed an increased expression level of a variety of apoplastic
acidic pathogenesis-related (PR) genes following enhanced H2O2 production. These results suggest that the expression of swpa4 in the apoplastic space may function as a positive defense signal in the H2O2-regulated stress response signaling pathway. 相似文献
967.
Integration of cytogenetic and genetic linkage maps unveils the physical architecture of tomato chromosome 2 总被引:1,自引:1,他引:0 下载免费PDF全文
We report the integration of the linkage map of tomato chromosome 2 with a high-density bacterial artificial chromosome fluorescence in situ hybridization (BAC-FISH)-based cytogenetic map. The euchromatic block of chromosome 2 resides between 13 and 142 cM and has a physical length of 48.12 microm, with 1 microm equivalent to 540 kb. BAC-FISH resolved a pair of loci that were 3.7-3.9 Mb apart and were not resolved on the linkage map. Most of the regions had crossover densities close to the mean of approximately 200 kb/cM. Relatively hot and cold spots of recombination were unevenly distributed along the chromosome. The distribution of centimorgan/micrometer values was similar to the previously reported recombination nodule distribution along the pachytene chromosome. FISH-based physical maps will play an important role in advanced genomics research for tomato, including map-based cloning of agronomically important traits and whole-genome sequencing. 相似文献
968.
Metabolic Behavior of Lactococcus lactis MG1363 in Microaerobic Continuous Cultivation at a Low Dilution Rate 总被引:1,自引:0,他引:1 下载免费PDF全文
Niels Bang Siemsen Jensen Claus Rix Melchiorsen Kirsten Vver Jokumsen John Villadsen 《Applied microbiology》2001,67(6):2677-2682
Minute amounts of oxygen were supplied to a continuous cultivation of Lactococcus lactis subsp. cremoris MG1363 grown on a defined glucose-limited medium at a dilution rate of 0.1 h−1. More than 80% of the carbon supplied with glucose ended up in fermentation products other than lactate. Addition of even minute amounts of oxygen increased the yield of biomass on glucose by more than 10% compared to that obtained under anaerobic conditions and had a dramatic impact on catabolic enzyme activities and hence on the distribution of carbon at the pyruvate branch point. Increasing aeration caused carbon dioxide and acetate to replace formate and ethanol as catabolic end products while hardly affecting the production of either acetoin or lactate. The negative impact of oxygen on the synthesis of pyruvate formate lyase was confirmed. Moreover, oxygen was shown to down regulate the protein level of alcohol dehydrogenase while increasing the enzyme activity levels of the pyruvate dehydrogenase complex, α-acetolactate synthase, and the NADH oxidases. Lactate dehydrogenase and glyceraldehyde dehydrogenase enzyme activity levels were unaffected by aeration. 相似文献
969.
The Sigma Factor AlgU (AlgT) Controls Exopolysaccharide Production and Tolerance towards Desiccation and Osmotic Stress in the Biocontrol Agent Pseudomonas fluorescens CHA0 总被引:3,自引:0,他引:3 下载免费PDF全文
Ursula Schnider-Keel Kirsten Bang Lejblle Eric Baehler Dieter Haas Christoph Keel 《Applied microbiology》2001,67(12):5683-5693
A variety of stress situations may affect the activity and survival of plant-beneficial pseudomonads added to soil to control root diseases. This study focused on the roles of the sigma factor AlgU (synonyms, AlgT, RpoE, and ς22) and the anti-sigma factor MucA in stress adaptation of the biocontrol agent Pseudomonas fluorescens CHA0. The algU-mucA-mucB gene cluster of strain CHA0 was similar to that of the pathogens Pseudomonas aeruginosa and Pseudomonas syringae. Strain CHA0 is naturally nonmucoid, whereas a mucA deletion mutant or algU-overexpressing strains were highly mucoid due to exopolysaccharide overproduction. Mucoidy strictly depended on the global regulator GacA. An algU deletion mutant was significantly more sensitive to osmotic stress than the wild-type CHA0 strain and the mucA mutant were. Expression of an algU′-′lacZ reporter fusion was induced severalfold in the wild type and in the mucA mutant upon exposure to osmotic stress, whereas a lower, noninducible level of expression was observed in the algU mutant. Overexpression of algU did not enhance tolerance towards osmotic stress. AlgU was found to be essential for tolerance of P. fluorescens towards desiccation stress in a sterile vermiculite-sand mixture and in a natural sandy loam soil. The size of the population of the algU mutant declined much more rapidly than the size of the wild-type population at soil water contents below 5%. In contrast to its role in pathogenic pseudomonads, AlgU did not contribute to tolerance of P. fluorescens towards oxidative and heat stress. In conclusion, AlgU is a crucial determinant in the adaptation of P. fluorescens to dry conditions and hyperosmolarity, two major stress factors that limit bacterial survival in the environment. 相似文献