Regulatory alpha-subunit of the voltage-gated potassium (Kv) channel which, when coassembled with KCNB1 or KCNB2, can modulate their expression and their gating kinetics by acting on deactivation upon repolarization and inactivation during maintained depolarization (PubMed:19074135). Potassium channel subunit that does not form functional channels by itself (PubMed:19074135). . This is the function of ENSG00000026559 (KCNG1, potassium voltage-gated channel modifier subfamily G member 1).