Potassium channel tetramerization domain-containing protein 16 (KCTD16)

Potassium channel tetramerization domain-containing protein 16 (KCTD16) is a cytoplasmic, predominantly neuronal protein that acts as an auxiliary subunit of the metabotropic GABA_B receptor complex[1][2][4]. It is not itself an ion channel but is named for its conserved N-terminal domain, which is homologous to the tetramerization domain of voltage-gated potassium channels[1][2]. KCTD16 assembles as an open pentamer and binds directly to the C-terminus of the GABA_B2 subunit, modifying the kinetics and signal transduction properties of the GABA_B receptor, particularly influencing the activation rate of linked downstream effectors like G protein-activated inwardly rectifying potassium (GIRK) channels[1][2]. KCTD16, along with other KCTD family members, confers subtype-specific properties on the GABA_B receptor—KCTD16 uniquely prevents desensitization of GABA_B responses in contrast to KCTD12, for example[1][2]. Recent studies also suggest KCTD16 may have non-neuronal roles and can participate in oncogenic fusion events, serving as a potential disease biomarker in select settings[4]. There are currently no approved therapeutic drugs that directly target KCTD16, but the protein's modulation of GABA_B receptor function may make it of future therapeutic interest in neuropsychiatric and neurodegenerative disease contexts[1][2][4].

Other names

BTB/POZ domain-containing protein KCTD16KIAA1317potassium channel tetramerisation domain-containing 16KCTD16

Not directly targeted by current drugs; modulation of GABA_B receptor signaling through auxiliary subunit interaction alters GABA_B receptor function and downstream signaling kinetics (not direct binding or inhibition/activation)[1][2].