Corepressor targeting diverse transcription regulators. Functions in brown adipose tissue (BAT) differentiation (By similarity). Isoform 2 probably acts as a scaffold for specialized synapses. Can form homodimers or heterodimers of CTBP1 and CTBP2. Interacts with HIPK2 and ZNF217. Interacts with PRDM16; represses white adipose tissue (WAT)-specific genes expression (By similarity). Interacts with PNN, NRIP1 and WIZ. Interacts with MCRIP1 (PubMed:25728771). (Microbial infection) Interacts with human adenovirus 5 E1A protein; this interaction seems to potentiate viral replication. Ubiquitous. Highest levels in heart, skeletal muscle, and pancreas. Belongs to the D-isomer specific 2-hydroxyacid dehydrogenase family.