Regulation of chloroplast gene expression by the maturase MatK

点击翻译按钮获取中文摘要

The intron maturase MatK is the only putative RNA splicing factor encoded in the chloroplast genome. Different from related monospecific bacterial maturases, MatK is capable of associating with multiple introns. While all other chloroplast RNA processing factors are nuclear encoded, MatK has been maintained in the chloroplast genome in all autotrophic, group II intron-containing streptophytes. Because of the fact that bacterial maturases have been demonstrated to regulate their own expression, it is here hypothesized that MatK is also involved in regulatory feed-back loops that require its expression in cis in the chloroplast and prevent transfer of the gene to the nucleus. To test this hypothesis, a three-pronged approach is proposed: (1) We will try to perturb the interaction of MatK with its own RNA by transplastomic approaches. (2) To embrace the larger MatK-network we will measure kinetics of various components known to interact with MatK or to be dependent on MatK function across tobacco development. This will allow developing a mathematical model of MatK-dependent regulation of gene expression in order to identify critical steps/factors in the network. (3) In order to understand also the biochemical network of MatK, we will characterize MatK-containing ribonucleoprotein particles by mass-spectrometry and additional biochemical techniques.