Corepressor targeting diverse transcription regulators. Functions in brown adipose tissue (BAT) differentiation (By similarity). Isoform 2 probably acts as a scaffold for specialized synapses. Interacts with the C-terminus of adenovirus E1A protein. Can form homodimers or heterodimers of CTBP1 and CTBP2. Interacts with HIPK2. Interacts with ZNF217, PNN, NRIP1 and WIZ. Interacts with PRDM16; represses white adipose tissue (WAT)-specific genes expression (By similarity). Interacts with MCRIP1 (By similarity). Isoform 2 is specifically localized in synaptic ribbon (at protein level). Belongs to the D-isomer specific 2-hydroxyacid dehydrogenase family.