FIGURE 2.

Two molecular mechanisms by which NF-Y modulates gene expression. (A) The NF-YB-YC heterodimers translocate into the nucleus and interact with NF-YA to form an active heterotrimer. This heterotrimer binds to the CCAAT box in the promoter regions of the target genes and mediates their expression. (B) The NF-YB-YC heterodimer interacts with the transcription factor (TF) to form a NF-YB-YC-TF heterotrimer and binds to specific cis-element (indicated by XXX). NF-YA can competitively inhibit the interaction of the TF with NF-YB/NF-YC.