Activates gene expression by recruiting HAG1/GCN5 and triggering subsequent histone H3 acetylation of target genes promoters. Interacts with HAG1/GCN5. Expressed in flowers, leaves, stems and siliques. Induced by cold and salt (PubMed:17151888). Probably repressed by HAG1/GCN5 (PubMed:17151888).