GO:0033613
— Molecular Function — activating transcription factor binding
GO:0043565
— Molecular Function — sequence-specific DNA binding
GO:0046982
— Molecular Function — protein heterodimerization activity
Family Introduction
NF-Y transcription factors are likely found in all eukaryotes and have roles in the regulation of diverse genes (McNabb et al., 1995; Edwards et al., 1998; Maity and de Crombrugghe, 1998; Mantovani, 1999). In mammals, where their biochemistry is well described, the NF-Y transcription factor complex is composed of three unique subunits: NF-YA, NF-YB, and NF-YC. Assembly of the NF-Y heterotrimer in mammals follows a strict, stepwise pattern (Sinha et al., 1995, 1996). Initially, a heterodimer is formed in the cytoplasm between the subunits NF-YB and NF-YC. This dimer then translocates to the nucleus, where the third subunit, NF-YA, is recruited to generate the mature, heterotrimeric NF-Y transcription factor (Frontini et al., 2004; Kahle et al., 2005). Mature NF-Y binds promoters with the core pentamer nucleotide sequence CCAAT, and this can result in either positive or negative transcriptional regulation(Peng and Jahroudi, 2002, 2003; Ceribelli et al., 2008).
As with NF-YA, NF-YB and NF-YC families have well-described subunit interaction and DNA-binding domains ( Kim et al., 1996; Sinha et al., 1996; McNabb et al., 1997; Romier et al., 2003). The conserved regions of NF-YB and NF-YC have structural and amino acid homology to histone fold motifs. Specifically, NF-YB is related to the histone fold motifs of H2B histones, while NF-YC subunits are related to H2A histones (Mantovani, 1999).
