Component of the NF-Y/HAP transcription factor complex. The NF-Y complex stimulates the transcription of various genes by recognizing and binding to a CCAAT motif in promoters. May act through association with MADS-box proteins. May regulate the expression of genes involved in flowering. Heterotrimeric transcription factor composed of three components, NF-YA, NF-YB and NF-YC. NF-YB and NF-YC must interact and dimerize for NF-YA association and DNA binding (By similarity). Interacts with MADS18. Forms a ternary complex with the MADS6-MADS18 heterodimer. Expressed in developing kernels. Probably not a component of a NF-Y/HAP transcription factor complex. Shows impaired association with NF-YA/HAP2 and CAAT motif binding. Belongs to the NFYB/HAP3 subunit family.