Sykes Aaron, Caruth Lannawill, Gross Sophia, Verma Shefali Setia, Hoshi Toshinori, Deutsch Carol
Department of Physiology, University of Pennsylvania, Philadelphia, PA 19104-6085, United States.
Department of Pathology and Laboratory Medicine, University of Pennsylvania, Philadelphia, PA 19104-6085, United States.
J Mol Biol. 2025 Sep 1;437(17):169226. doi: 10.1016/j.jmb.2025.169226. Epub 2025 May 21.
Nascent proteins fold in a stepwise manner during all stages of biogenesis. This progression is particularly complex for ion channels composed of multiple biogenic and functional domains and subunits. The human Kv1.3 ion channel, encoded by KCNA3, is expressed in neuronal and immune cells. Its dysregulation produces chronic inflammatory disease and autoimmune disorders, which affect many in the US population, especially women. Using the unbiased 'genome-first' approach with integrated patient biobank databases, we identified KCNA3 gene variants associated with human disease and examined their impact on Kv1.3 channel biogenesis. Our tertiary and quaternary folding assays and all-atom molecular dynamics simulations show that KCNA3 gene variants in T1, the channel's intersubunit recognition domain, manifest early-stage T1 folding defects, energetic instabilities, and conformational distortion of subunits concomitant with tertiary unwinding. These findings identify molecular mechanisms by which patient-associated variants influence channel assembly, potentially contributing to diverse clinical phenotypes underlying human disease.
新生蛋白质在生物合成的所有阶段都以逐步的方式折叠。对于由多个生物发生和功能结构域及亚基组成的离子通道而言，这种进程尤为复杂。由KCNA3编码的人类Kv1.3离子通道在神经元和免疫细胞中表达。其失调会引发慢性炎症性疾病和自身免疫性疾病，影响了许多美国人群，尤其是女性。通过使用具有整合患者生物样本库数据库的无偏倚“基因组优先”方法，我们鉴定出了与人类疾病相关的KCNA3基因变体，并研究了它们对Kv1.3通道生物合成的影响。我们的三级和四级折叠测定以及全原子分子动力学模拟表明，通道亚基间识别结构域T1中的KCNA3基因变体表现出早期T1折叠缺陷、能量不稳定性以及伴随着三级解旋的亚基构象扭曲。这些发现确定了患者相关变体影响通道组装的分子机制，这可能导致人类疾病潜在的多种临床表型。
