LRRC55 modulates BK channels to support Purkinje cell plasticity and motor coordination.

ABSTRACT: Large-conductance Ca²⁺- and voltage-activated K⁺ (BK) channels are widely expressed, including in the brain where they shape neuronal excitability. Their physiological functions are strongly influenced by cell-type-specific auxiliary subunits. The auxiliary γ3 subunit (LRRC55) enhances BK-channel activation by shifting voltage-dependent gating toward more negative potentials; however, its protein distribution and in vivo function remain unclear. Here, we generated knock-in mice carrying a C-terminal epitope tag on endogenous LRRC55 to map its expression, and Lrrc55 knockout mice to test its function. LRRC55 protein was selectively enriched in cerebellar Purkinje cells. Lrrc55 deletion produced ataxia-like impairments in gait, balance, and coordination. I

SUBMITTER: Guan X 

PROVIDER: S-EPMC12873909 | biostudies-literature | 2026 Feb

REPOSITORIES: biostudies-literature