Abstract
The Small Acidic Protein 1 (SMAP1) gene was identified as a regulator for 2,4-D response in Arabidopsis root. SMAP1 has the conserved phenylalanine and aspartate rich region (F/D region) in its C terminal. Previously, we reported that the F/D region is essential for the SMAP1 function and that SMAP1-GFP binds to COP9 signalosome (CSN). In this study, to further elucidate the interaction between SMAP1 and CSN, GST-tagged SMAP1 proteins were expressed in E. coli, purified, mixed with total proteins of aar1 that lacks SMAP1 gene, and examined by pull-down and western analysis. The GST-SMAP1 and GST-F/D proteins were pulled down with CSN but not GST-SMAP1ΔF/D, suggesting that the F/D region was required and sufficient for the interaction between SMAP1 and CSN.
