BAM7 and BAM8 Are Nuclear Proteins Comprising a Putative DNA Binding Domain of the BZR1-Type and a Glycoside Hydrolase–Like Domain.
(A) Protein models of Arabidopsis BAM3, BAM7, BAM8, and BZR1. Red, BZR1 domain; yellow, glycoside–hydrolase family 14 domain; green, transit peptide (TP; Fulton et al. 2008) for chloroplast localization; cyan, putative bipartite nuclear localization signal. aa, amino acids.
(B) Transiently expressed BAM7-GFP and BAM8-GFP in Arabidopsis protoplasts localize to nucleus. Localization studies were performed using C-terminal GFP fusions with the complete BAM7 and BAM8 sequence. Chlorophyll autofluorescence (Chl) and 4′,6-diamidino-2-phenylindole (DAPI) staining serve as markers for chloroplasts and nuclei, respectively.
(C) Immunoblots of total homogenate, soluble, and nuclear-enriched fractions from the wild-type plants using an anti-BAM8 antibody. The majority of the endogenous BAM8 protein was detected in the nuclear fraction.Disproportionating enzyme2 (DPE2) and Histone3 (H3) are used as cytosolic and nuclear markers, respectively. Molecular weight markers are indicated in kilodaltons.
(D) Immunoblots of total homogenate, soluble, and nuclear-enriched fractions from HA-BAM7–overexpressing plants using an anti-HA antibody. HA-BAM7 protein was primarily detected in the nuclear fraction.