Molecular cloning and characterisation of the general control non-derepressible 2 protein kinase from Triticum aestivum.
Doctoral thesis, UCL (University College London).
General control non-derepressible 2 (GCN2) is a kinase that functions to sense and respond to amino acid starvation. GCN2 was first identified in yeast where it senses a reduction in cellular amino acid concentration and responds by phosphorylating the eukaryotic translation initiation factor 2 (eIF2), which is one of the principle proteins involved in translation initiation. GCN2 therefore acts as a master control switch, regulating global protein synthesis in response to amino acid availability in the cell. The aim of this project was to elucidate components of the GCN2 signalling pathway in wheat. GCN2 cDNA was identified and cloned, the nucleotide and peptide sequence analysis revealed it be a genuine GCN2-like kinase. Under normal nutrient conditions, analysis of expression and abundance revealed wheat GCN2 to exist at steady levels in leaves and under developmental control in grain. Levels of GCN2 increased in response to nitrogen deprivation. In order to further understand the role of GCN2 in wheat, transgenic wheat lines were produced in which GCN2 was either knocke-down by RNAi, or overexpressed. Wheat plants were genetically modified using particle bombardment and grown to the T2 or T3 generation for analysis. Analysis of the grain from transgenic plants revealed altered free amino acid levels, some transgenic plants were found to have an increased yield relative to the controls. The results suggest that TaGCN2 is involved in the link between free amino acid levels and protein synthesis in the grain.
|Title:||Molecular cloning and characterisation of the general control non-derepressible 2 protein kinase from Triticum aestivum|
|Additional information:||Permission for digitisation not received|
|UCL classification:||UCL > School of Life and Medical Sciences > Faculty of Life Sciences > Biosciences (Division of) > Genetics, Evolution and Environment|
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