Generation of tools for visualizing understudied KvS potassium channel proteins

摘要

Abstract Voltage-gated ion channels are modulated by many existing drugs and the targets of pharmaceutical development programs to treat a diverse array of maladies. A major obstacle to developing ion channel drugs is identification and validation of molecular targets that ameliorate disorders while limiting side effects. Recently, transcriptomics projects have identified transcripts for KvS voltage-gated K+ channels in somatosensory and motor neuron subtypes, suggesting that studying these KvS subunits could potentially identify strategies to ameliorate neuropathic pain or motor dysfunctions. KvS proteins are voltage-gated K+ channel subunits which are “electrically silent” unless they coassemble with voltage-gated K+ channel subunits of the Kv2 family. The function of many KvS subunits and their role in disease remains largely unexplored, however, as there are few or no research tools for these subunits. The Illuminating the Druggable Genome program has appropriately identified several KvS family members as “understudied” including KCNG2-4 (encoding Kv6.2-6.4) and KCNS1 (encoding Kv9.1). Gene expression studies show that these KvS subunits are robustly expressed in select spinal cord and dorsal root ganglia neurons where their participation in electrical signaling would be expected to influence movement, proprioception, and pain. However, there is little information available on the expression of these KvS subunits at the protein level due to a lack of well-validated reagents for their detection in native tissue. The objectives of this project are (i) to develop specific monoclonal antibody and genetically-encoded tools to visualize understudied KvS subunits, and (ii) to use these reagents to define the cellular and subcellular localization of KvS subunits in spinal cord and dorsal root ganglia neurons. These tools and information on where Kv2/KvS heterotetrameric channels are expressed will provide an essential platform for further studies on the physiological role of KvS subunits and their role in neurological disorders and potential utility as drug targets. This research could potentially identify specific KvS subunits as selective drug targets for the treatment of motor and sensory neuron disorders, including excitotoxicity in amyotrophic lateral sclerosis, and hypersensitivity in neuropathic pain.