The transcription factor interacting protein RCD1 contains a novel conserved domain.

The RCD1 protein is a regulator of both developmental and stress responses in Arabidopsis thaliana and it interacts with several transcription factors. Its closest homolog, SRO1, seems to be dispensable for proper plant responses but the hardly viable phenotype of the rcd1 sro1 double mutant reveals that it encodes a functional protein that can partially compensate for the loss of RCD1 in the single rcd1 mutant. Both RCD1 and SRO1 contain a WWE domain, the catalytic core of poly(ADP-ribose) polymerases and a novel conserved domain termed RST which is also found in the transcription initiation complex component TAF4. Here we summarize recent findings on the protein-protein interactions mediated by RCD1 and highlight the different functional possibilities that form the basis of our future experiments concerning the biochemical function of RCD1.