Global ETD Search

1	The Bromodomain Proteins GTE9 and GTE11 Associate with BT2-based E3 Ligase Complex and Mediate Responses to Multiple Signals in Arabidopsis thaliana. Misra, Anjali 2011 December 1900 (has links) BT2 is an Arabidopsis thaliana protein with N-terminal BTB, central TAZ and a C-terminal calmodulin binding domain and associates with Cullin3 to form an E3 ubiquitin ligase. We have shown previously that BT2 regulates telomerase activity in mature vegetative organs and controls a variety of hormone, stress and metabolic responses in Arabidopsis thaliana. Loss of BT2 results in plants that are hypersensitive to inhibition of germination by ABA and sugars. Conversely, overexpression of BT2 results in resistance to ABA and sugars, suggesting that BT2 is a negative regulator of ABA and sugar responses. Here, we report the roles of BT2-interacting partners GTE9 and GTE11, bromodomain and extraterminal-domain proteins of Global Transcription Factor Group E, in BT2-mediated responses to sugars and hormones. Loss-of-function mutants gte9-1 and gte11-1 phenocopy the bt2-1-null mutant responses; germination in all three mutants is hypersensitive to inhibition by glucose and ABA. Loss of either GTE9 or GTE11 in a BT2 over-expressing background blocks resistance to sugars and ABA, indicating that both GTE9 and GTE11 are required for BT2 function. Additionally, loss of GTE9 or GTE11, similar to loss of BT2, suppresses transcriptional gene activation mediated by CaMV 35S enhancers in Arabidopsis. The suppressed phenotype was accompanied by decreased transcription and hypermethylation of the 35S enhancers in the activation-tagged lines. We showed that BT2 and GTE9 co-immunoprecipitate and physically interact in vivo to mediate diverse responses to biotic and abiotic signals and 35S enhancer activity. Our working model is that the GTE9 and GTE11 function as chromatin adaptors that localize the BT2-CULLIN3 E3 ubiquitin ligase complex to acetylated chromatin on transcriptionally competent promoters in response to calcium signals detected by BT2’s calmodulin-binding domain. Bromodomain protein Global transcription Factor group E Arabidopsis GTE protein Arabidopsis BET protein
2	Synthesis and characterisation of substituted smithsonite and calcite Hales, Matthew Cameron January 2008 (has links) Carbonate minerals play a very important role in nature, they represent some of the most diverse and common mineral species on the Planet. They are directly involved in the carbon dioxide (CO2) cycle acting as relatively stable long term chemical storage reservoirs, moderating both global warming trends and oceanaquatic chemistry through carbonate buffering systems. A range of synthetic metal carbonates have been synthesised for analysis under multiple experimental conditions, in order to study the variation in physical and chemical properties such as phase specificity, metal substitution, hydration/hydroxy carbonate formation under varying partial pressures of CO2 and thermal stability. Synthetic samples were characterised by a variety of instrumental analysis techniques in order to investigate chemical purity and phase specificity. Some of the techniques included, vibrational spectroscopy (IR/Raman), thermal analysis (TGA-MS) (thermal Raman), X-Ray diffraction (XRD) and electron microscopy (SEM-EDX). From the instrumental characterisation techniques, it was found that single phase smithsonite, hydrozincite, calcite and nesquehonite could successfully be synthesised under the conditions used. Minor impurities of other minerals and / or phases were found to form under specific chemical or physical conditions such as in the case of hydrozincite / simonkolleite if zinc chloride was used during hydrothermal synthesis. Raman Infrared IR spectroscopy characterisation synthesis synthetic natural scanning electron microscopy SEM thermo-gravimetric analysis mass spectroscopy TGA-MS X-Ray diffraction XRD carbonate hydrogen carbonate hydroxy hydrate minerals crystal point group factor group phase symmetry elements calcite magnesite aragonite vaterite aurichalcite azurite malachite hydrozincite zincite nesquehonite strontianite witherite oxide zone partial pressure carbon dioxide CO2 geological settling coral geo-sequestration green house gas

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The Bromodomain Proteins GTE9 and GTE11 Associate with BT2-based E3 Ligase Complex and Mediate Responses to Multiple Signals in Arabidopsis thaliana.

Synthesis and characterisation of substituted smithsonite and calcite