Potassium channel tetramerization domain-containing protein 3 (KCTD3)

Potassium channel tetramerization domain-containing protein 3 (KCTD3) is a cytoplasmic protein that is a member of the KCTD protein family, characterized by an N-terminal BTB/POZ domain which mediates protein–protein interactions. KCTD3 acts as an accessory subunit for hyperpolarization-activated cyclic nucleotide-gated channel 3 (HCN3), increasing its cell-surface expression and current density without altering its channel voltage dependence or kinetics. In humans, KCTD3 mutations—particularly biallelic loss-of-function variants—are associated with severe neurodevelopmental syndromes, including developmental and epileptic encephalopathies with global developmental delay and structural brain defects. KCTD family proteins, including KCTD3, also act as adaptors for Cullin 3-based ubiquitin ligases, potentially affecting protein ubiquitination and degradation processes relevant to multiple cellular signaling pathways. KCTD3 is also known as NY-REN-45, a renal carcinoma antigen, but a direct mechanistic connection to cancer has not been elucidated. There are no approved drugs or established mechanisms of therapeutic targeting specific to KCTD3, nor validated biomarkers or safety issues directly attributed to its modulation.

Other names

BTB/POZ domain-containing protein KCTD3NY-REN-45Renal carcinoma antigen NY-REN-45NY-REN-45 antigen