Transcription factor required for normal cell differentiation. Interacts directly with asymmetric leaves 2 (AS2) to repress the knox homeobox genes. Homodimer. Interacts with AS2, WRKY1, HIRA, a probable histone chaperone, and RIK, a predicted RNA binding protein. Localized in discrete subnuclear bodies. Expressed in lateral organ promordia. A C-terminal domain (245-347) is required for dimerization.