The Arabidopsis CPSF30 ortholog (AtCPSF30) is an RNA-binding endonuclease that is part of the plant polyadenylation complex. Previous work (B. Addepalli, A.G. Hunt, Nucleic Acids Res. 35 (2007) 4453-4463) demonstrated that different zinc finger motifs in the protein were responsible for RNA-binding and nuclease activity, respectively. In this study, a more detailed functional map of AtCPSF30 is presented, a map that includes descriptions of novel biochemical activities. Elevated temperatures, the specific zinc chelator 1,10-phenanthroline, and the sulfhydryl reagent dithiothreitol all had differential inhibitory effects on the RNA-binding and nuclease activities. The endonuclease activity of AtCPSF30 was inhibited by relatively high (>100 μM) concentrations of zinc, and this inhibition required a plant-specific N-terminal domain apart from the zinc finger core of the protein. ATP stimulated the nuclease activity in the presence of zinc, and this stimulation required a plant-specific C-terminal domain, again apart from the zinc finger core. These studies reveal a subtle and unexpected complexity to AtCPSF30, and raise the possibility that multiple avenues of regulation may impinge on this protein through different functional domains.
|Number of pages||8|
|Journal||Archives of Biochemistry and Biophysics|
|State||Published - May 1 2008|
Bibliographical noteFunding Information:
The authors thank Carol Von Lanken for excellent technical and administrative support. This work was supported by NSF Arabidopsis 2010 Grant MCB-0313472.
- CCCH zinc finger
ASJC Scopus subject areas
- Molecular Biology