Role of NAD binding and catalytic residues in the C-terminal binding protein corepressor.

CtBP corepressor proteins potentiate the activity of many metazoan transcriptional repressors. These proteins are homologous to prokaryotic D-2-hydroxyacid dehydrogenases, possessing an NAD/NADH binding fold and conserved active site residues. When expressed in Drosophila, a catalytic site mutant retains biological activity, however, we find that an NAD binding mutant lacks biological activity.

Developmental expression and phylogenetic conservation of alternatively spliced forms of the C-terminal binding protein corepressor.

The C-terminal binding protein (CtBP) is an evolutionarily conserved transcriptional corepressor found in multicellular eukaryotes. Multiple forms of the protein are typically found in animal cells, produced from separate genes and by alternative splicing. CtBP isoforms have also been implicated in cytoplasmic functions, including Golgi fission and vesicular trafficking.