Maurel Cindy, Scherer Natalie M, Luu Luan, Radford Rowan A, Hogan Alison, Merjane Jessica, Vidal-Itriago Andres, Don Emily K, Chapman Tyler, Cull Stephen, Vourc'h Patrick, Lisowski Leszek, Lee Albert, Chung Roger S, Morsch Marco
Faculty of Medicine, Health & Human Sciences, Macquarie Medical School, MND Research Centre, Macquarie University, Sydney, NSW 2109, Australia.
Translational Vectorology Research Unit, Children's Medical Research Institute, Faculty of Medicine and Health, The University of Sydney, Westmead, NSW 2145, Australia.
iScience. 2025 May 27;28(7):112761. doi: 10.1016/j.isci.2025.112761. eCollection 2025 Jul 18.
TDP-43 is a nuclear RNA-binding protein that undergoes liquid-liquid phase separation (LLPS) and forms insoluble aggregates in neurodegenerative diseases. By studying TDP-43 in living vertebrates, we confirmed that TDP-43 undergoes LLPS and forms dynamic biomolecular condensates in spinal motor neurons. We validated that interfering with the lysine residue at position 136 altered the phase separation behavior of TDP-43 by reducing cytoplasmic mislocalization and aggregation. These alterations were post-translational modification (PTM) independent, highlighting that residue 136 is a key structural regulator of TDP-43 function. We further established an adeno-associated virus (AAV)-mediated expression approach in mice that confirmed altered nuclear condensation characteristics of lysine-modified TDP-43. These assessments exposed the formation of dynamic nuclear TDP-43 condensates and emphasize the important role of lysine 136 in maintaining TDP-43 function. Altogether, we establish lysine 136 as a molecular regulator for phase separation and TDP-43 aggregation in amyotrophic lateral sclerosis (ALS) in two platforms.
TDP-43是一种核RNA结合蛋白，在神经退行性疾病中会发生液-液相分离（LLPS）并形成不溶性聚集体。通过在活体脊椎动物中研究TDP-43，我们证实TDP-43会发生LLPS，并在脊髓运动神经元中形成动态生物分子凝聚物。我们验证了干扰136位赖氨酸残基可通过减少细胞质错误定位和聚集来改变TDP-43的相分离行为。这些改变与翻译后修饰（PTM）无关，突出表明136位残基是TDP-43功能的关键结构调节因子。我们进一步在小鼠中建立了一种腺相关病毒（AAV）介导的表达方法，该方法证实了赖氨酸修饰的TDP-43的核凝聚特征发生了改变。这些评估揭示了动态核TDP-43凝聚物的形成，并强调了赖氨酸136在维持TDP-43功能中的重要作用。总之，我们在两个平台上确定赖氨酸136是肌萎缩侧索硬化症（ALS）中相分离和TDP-43聚集的分子调节因子。
