Component of the sequence-specific heterotrimeric transcription factor (nfya-2-NF-Y) which specifically recognizes a 5'-CCAAT-3' box motif found in the promoters of its target genes to regulate their expression and control cellular identity in particular tissue types (PubMed:17574230). In association with the components in the nfya-2-NF-Y complex, may repress the expression of the T-box transcription factor tbx-2 throughout larval development, which most likely restricts its expression to certain tissues (PubMed:23933492). Forms a heterotrimeric transcription factor complex (nfya-2-NF-Y complex) composed of nfya-2, nfyb-1 and nfyc-1 (PubMed:17574230). Interacts with the nfyb-1 and nfyc-1 dimer; the interaction is required for subsequent binding to the 5'-CCAAT-3' box motif in DNA (PubMed:17574230). Does not interact with either nfyb-1 or nfyc-1 in their monomeric form (PubMed:17574230). Highly expressed in certain parts of the gonads (PubMed:15704008). Expressed in the spermatheca, intestine and in some neurons in the head (PubMed:17574230). Not expressed in the intestine, the hypodermis, body wall muscle surrounding the pseudocoelomic space, secretory cells in the pharyngeal terminal bulb wall, in the small ganglia surrounding the pharynx and in the neurons running anteriorly to the sensory organs in the head (PubMed:15704008). Expressed at all developmental stages (PubMed:17574230). Highly expressed in the intestine at all developmental stages (PubMed:17574230). RNAi-mediated knockdown results in weak ectopic expression of tbx-2 in seam cells of the head in young adults. Belongs to the NFYA/HAP2 subunit family.