Project description:Glutathione peroxidase (Gpx) is a selenium-containing enzyme that catalyses the reduction of a variety of biological peroxides at the expense of reduced glutathione (GSH). Gpx1 is the most abundant isoform and its role has been implicated in neurodegenerative disorders such as Parkinson’s disease (PD), dementia with Lewy bodies tissue (DLB) (Power and Blumbergs, 2009) and traumatic brain injury (Tsuru-Aoyagi et al., 2009). Due to its high abundance, mutation of the Gpx1 allele would lower overall Gpx activity in the brain significantly. Gpx1 knockout (Gpx1-/-) mice do not show overt phenotypic differences, but all indications suggest that these mice are in a chronic “pro-oxidant” state (Cheng et al. 1999; de Haan et al. 2004). Indeed, a recent study from our laboratory illustrated that the absence of Gpx1 exacerbated stroke injury via increased ROS production and vascular permeability (Wong et al. 2008). Furthermore, Gpx1-/- mice demonstrated an increase in caspase-3 activation and greater infarct volume (Crack et al. 2001)
Project description:The tea plant (Camellia sinensis (L.) O. Kuntze) is often commercially used as a source of non-alcoholic beverages and is an economically important woody crop (Chen et al., 2007). As living standards have improved, the requirement for high-quality life has increased in modern society. ‘Anji Baicha’ (alias ‘Baiye 1’ or ‘White Leaf 1’) is an excellent tea cultivar with albino phenotype and it is popular in producing high-quality green tea. The traits of ‘Anji Baicha’ are as follows. Young ‘Anji Baicha’ shoots are yellow-green when the early spring temperature is below 20°C. As the leaves fully expand, the leaves become white. The leaves gradually return to green when the environmental temperature increases (Cheng et al., 1999; Li et al., 2002, 2011). Previous reports have suggested a positive correlation between amino acid concentration and albinism as well as a negative correlation between tea polyphenols and albinism (Li et al., 1996; Du et al., 2006; Xiong et al., 2013). Therefore, the quality of ‘Anji Baicha’ is much higher when new shoots become albino due to their rich amino acid content and modest tea polyphenol content. Plants adjust their metabolism in response to environmental stimuli to eventually bring about changes in protein activities and levels, and this adaptive process includes posttranslational protein modifications (PTMs) (Prabakaran et al., 2012). PTMs have been reported to regulate various processes, including DNA interaction, protein-protein interactions, enzyme activation and protein stability. Among the hundreds of different PTMs, lysine acetylation is an abundant, reversible and highly regulated PTM (Zhang et al., 2009; Wu et al., 2011).