Component of the SWR1 complex which mediates the ATP-dependent exchange of histone H2A for the H2A variant H2A.F/Z leading to transcriptional regulation of selected genes (e.g. FLC) by chromatin remodeling. Coodinates SWR1-C, FRI-C (FLC transcription activator complex), histone methyltransferase and general transcription factors. Represses flowering by positively regulating FLC and MAF4. Binds to the promoter region of FLC chromatin. Homodimer. Component of the SWR1 chromatin-remodeling complex composed of at least ARP6/ESD1/SUF3, PIE1, SWC6, SWC2 and H2AZs (HTA8, HTA9, HTA11). Interacts directly with ARP6, PIE1 and SWC2. Interacts with FLX and SUF4, two component of the transcription activator complex FRI-C, and with ASHH2 and TAF14. Relocates to the nuclear periphery when interacting with ARP6. Expressed in root, lateral root primordia, shoot apex, leaves, stems, inflorescences, flowers, axillary buds, developing siliques and premature seeds. Not regulated by circadian rhythm, photoperiod or vernalization. Early flowering, leaf serration, production of extra petals and weak apical dominance. Belongs to the ZNHIT1 family.