The nuclear-encoded RNA polymerase RpoT;2 from Arabidopsis
thaliana differs from the polymerases that transcribe the
plant's nuclear genes and resembles RNA polymerases from
bacteriophages. In the 15 November EMBO Reports, Hedtke et al.
describe the use of GFP (green fluorescent protein) fusion
proteins to examine the subcellular localization of RpoT;2 (EMBO
Reports 2000, 1:435-440). The RpoT;2 transit peptide targeted
GFP fusion proteins to both mitochondrial and chloroplast
compartments in tobacco protoplasts and transgenic Arabidopsis
plants. RpoT;2 may therefore be able to transcribe genes from
two different genomes. This is in contrast to two other phage-
type RNA polymerases from Arabidopsis, which are exclusively
targeted to either mitochondria (RpoT;1) or chloroplasts
(RpoT;3). GFP applications page