Medicinal and Pharmaceutical Chemistry Commons^™

Loss-Of-Function KCa2.2 Mutations Abolish Channel Activity, Young-Woo Nam, Mohammad Asikur Rahman, Grace Yang, Razan Orfali, Meng Cui, Miao Zhang

Pharmacy Faculty Articles and Research

Small-conductance Ca²⁺-activated potassium channels subtype 2 (K_Ca2.2, also called SK2) are operated exclusively by a Ca²⁺-calmodulin gating mechanism. Heterozygous genetic mutations of K_Ca2.2 channels have been associated with autosomal dominant neurodevelopmental disorders including cerebellar ataxia and tremor in humans and rodents. Taking advantage of these pathogenic mutations, we performed structure-function studies of the rat K_Ca2.2 channel. No measurable current was detected from HEK293 cells heterologously expressing these pathogenic K_Ca2.2 mutants. When co-expressed with the K_Ca2.2_WT channel, mutations of the pore-lining amino acid residues (I360M, Y362C, G363S …