Transcription factor that binds to specific DNA sequences in target gene promoters. BZIP2-BZIP63-KIN10 complex binds to the ETFQO promoter to up-regulate its transcription (PubMed:29348240). Forms heterodimers with BZIP9, BZIP10, BZIP25 and BZIP63 (PubMed:16709202). Component of a ternary complex composed of BZIP2-BZIP63 heterodimer and KIN10 (PubMed:29348240). Expressed in the shoot meristem during vegetative to reproductive phase transition.