The C-terminal region (640-967) of Arabidopsis CPL1 interacts with the abiotic stress- and ABA-responsive transcription factors

Abstract Proteins in CPL1 family are unique to plants and contain a phosphatase catalytic domain and double-stranded RNA (dsRNA)-binding motifs (DRMs) in a single peptide. Though DRMs are important for the function of Arabidopsis CPL1 in vivo , the role of CPL1 DRM has been obscure. We have isolated two transcription factors, ANAC019 ( At1g52890 ) and AtMYB3 ( At1g22640 ), which specifically interact with the C-terminal region (640–967) of AtCPL1 containing two DRMs. Detailed interaction analysis indicated that AtMYB3 specifically interacted with the first DRM but not with the second DRM in CPL1 C-terminal fragment. GFP-fusion analysis indicated that AtMYB3 localized in nuclei-like CPL1, and its expression is induced by abiotic stress and ABA treatment. These results suggest that AtMYB3 function in abiotic stress signaling in concert with CPL1.