CTBP2

C-terminal-binding protein 2 also known as CtBP2 is a protein that in humans is encoded by the CTBP2 gene.

Function

The CtBPs - CtBP1 and CtBP2 in mammals - are among the best characterized transcriptional corepressors. They typically turn their target genes off. They do this by binding to sequence-specific DNA-binding proteins that carry a short motif of the general form Proline-Isoleucine-Aspartate-Leucine-Serine (the PIDLS motif). They then recruit histone modifying enzymes, histone deacetylases, histone methylases and histone demethylases. These enzymes are thought to work together to remove activating and add repressive histone marks. For example, histone deacetylase 1 (HDAC1) and HDAC2 can remove the activating mark histone 3 acetyl lysine 9 (H3K9Ac), then the histone methylase G9a can add methyl groups, while the histone demethylase lysine specific demethylase 1 (LSD1) can remove the activating mark H3K4me.

The CtBPs bind to many different DNA-binding proteins and also bind to co-repressors that are themselves bound to DNA-binding proteins, such as Friend of GATA (Fog). CtBPs can also dimerize and multimerize to bridge larger transcriptional complexes. They appear to be primarily scaffold proteins that allow the assembly of gene repression complexes.