CLC-2 voltage-gated chloride channel structure and ligand recognition

在中枢神经系统（CNS）中，电压门控离子通道在动作电位形成中起着重要作用

In the central nervous system (CNS), voltage-gated ion channels play central roles in shaping action-potential firing. The cation-selective voltage-gated channels – sodium (Na+), potassium (K+), and calcium (Ca2+)) channels – have received intense scrutiny over the past decades. In contrast, the chloride (Cl–)-selective voltage-gated channel, CLC-2, is less well understood, despite its broad expression in neurons and glia throughout the CNS. A complete understanding of CLC-2’s contribution to CNS function will include an understanding of CLC-2’s molecular structure. Structurally, CLC channels possess a unique double-barreled architecture and operate through distinct gating (opening/closing) mechanisms that differ markedly from those of the well-studied Na+, K+, and Ca2+ channels. In addition to providing a critical framework for studying CLC-2 channel gating and permeation mechanisms, another compelling rationale for determining the CLC-2 structure is its value for understanding ligand interactions and guiding design of small-molecule probes. Such probes would be of great value in investigations of CLC-2 neurophysiology. Accordingly, the goal of this R21 project is develop expression and purification protocols for CLC-2 and to use cryo-electron microscopy to determine CLC-2 structures in the absence and presence of the selective CLC-2 inhibitor AK-42.