Transcriptional regulator involved in leaf proximal/distal patterning. May act by sequestering BELL transcription factors. Interacts with KNAT1, KNAT3, KNAT4, BEL1, BLH2, BLH4 and BLH9, but not with BLH8 or the KNATM-A and KNATM-C isoforms. Isoforms KNATM-A and KNATM-C: no interactions with KNATM-B, KNOXX or BELL proteins. Detected in inflorescences, seedlings, leaves, hydathodes, stems, roots, embryo and siliques. Expressed in a polar pattern in organ primordia and at the boundary of mature organs. Detected in the lateral domains of flower meristems, but not in the inflorescence meristem or the vegetative shoot apical meristem. Down-regulated by the AS1 repressor complex including HDA6. The MEINOX domain (33-138) is sufficient for interactions with BELL proteins (PubMed:18398054). The BP-interacting domain (BPID, 1-32) is necessary for interactions with KNOX proteins (PubMed:18398054).