Amyotrophic lateral sclerosis (ALS) is a devastating neurodegenerative disorder characterized by the progressive degeneration of motor neurons, leading to muscle weakness, paralysis, and death. Although significant progress has been made in understanding ALS, its molecular mechanisms remain complex and multifactorial. This review explores the potential convergent mechanisms underlying ALS pathogenesis, focusing on the roles of key proteins including NEK1, C21ORF2, cyclin F, VCP, and TDP-43. Recent studies suggest that mutations in C21ORF2 lead to the stabilization of NEK1, while cyclin F mutations activate VCP, resulting in TDP-43 aggregation. TDP-43 aggregation, a hallmark of ALS, impairs RNA processing and protein transport, both of which are essential for neuronal function. Furthermore, TDP-43 has emerged as a key player in DNA damage repair, translocating to DNA damage sites and recruiting repair proteins. Given that NEK1, VCP, and cyclin F are also involved in DNA repair, this review examines how these proteins may intersect to disrupt DNA damage repair mechanisms, contributing to ALS progression. Impaired DNA repair and protein homeostasis are suggested to be central downstream mechanisms in ALS pathogenesis. Ultimately, understanding the interplay between these pathways could offer novel insights into ALS and provide potential therapeutic targets. This review aims to highlight the emerging connections between protein aggregation, DNA damage repair, and cellular dysfunction in ALS, fostering a deeper understanding of its molecular basis and potential avenues for intervention.

Amyotrophic lateral sclerosis (ALS) is a neurodegenerative disease characterized by selective loss of motor neurons. Although multiple pathophysiological mechanisms have been identified, no comprehensive understanding of these heterogeneous processes has been achieved. The ALS-associated RNA-binding protein (RBP) TDP-43 has previously been shown to stabilize UNC13A mRNA by preventing cryptic exon inclusion. Here, we show that the ALS-associated RBPs MATR3, FUS, and hnRNPA1 regulate UNC13A expression by targeting the transcriptional repressor REST. These RBPs bind to and downregulate REST mRNA to promote UNC13A transcription. Loss of any of these RBPs in cultured cells or in iPSC-derived motor neurons carrying the ALS-causing FUS P525L mutation leads to REST overexpression, and the same is observed in motor neurons of individuals with familial or sporadic ALS. The functional convergence of four RBPs on the regulation of UNC13A expression underscores the important role of this process for synaptic integrity, and its association with ALS pathogenesis could be relevant for the development of new therapeutic agents.

Dysferlinopathy is an adult‐onset form of muscular dystrophy caused by mutations in the dysferlin gene and is inherited in an autosomal recessive manner. Dysferlin is primarily known for its role in plasma membrane repair. Although several proteins associated with dysferlin have been identified, many aspects of its signaling pathways and protein–protein interactions remain unclear. Here, we focused on the region between the third and fourth C2 domains, where frequent genetic mutations occur and functional domains are concentrated, and identified the protein kinase CK2α (formerly known as casein kinase 2) as a novel dysferlin‐binding protein. CK2α was found to accumulate at membrane injury sites along with dysferlin in mouse skeletal muscle, and membrane repair was delayed in CK2α knockout cells. Furthermore, overexpression of CK2α in dysferlin‐deficient mouse muscle led to improved membrane repair. Additionally, we revealed that CK2α plays a role in phosphorylating annexin A1, which is known to bind to dysferlin and is involved in plasma membrane repair. Our results indicated that CK2α controls membrane repair by participating in the phosphorylation of annexin A1. The molecular interplay among dysferlin, CK2α, and phosphorylated annexin A1 represents a novel therapeutic target for promoting membrane repair.

Amyotrophic lateral sclerosis (ALS) is a devastating neurodegenerative disorder characterized by the progressive degeneration of motor neurons, leading to muscle weakness, paralysis, and death. Although significant progress has been made in understanding ALS, its molecular mechanisms remain complex and multifactorial. This review explores the potential convergent mechanisms underlying ALS pathogenesis, focusing on the roles of key proteins including NEK1, C21ORF2, Cyclin F, VCP, and TDP-43. Recent studies suggest that mutations in C21ORF2, lead to the stabilization of NEK1, while Cyclin F mutations activate VCP, resulting in TDP-43 aggregation. TDP-43 aggregation, a hallmark of ALS, impairs RNA processing and protein transport, both of which are essential for neuronal function. Furthermore, TDP-43 has emerged as a key player in DNA damage repair, translocating to DNA damage sites and recruiting repair proteins. Given that NEK1, VCP, and Cyclin F are also involved in DNA repair, this review examines how these proteins may intersect to disrupt DNA damage repair mechanisms, contributing to ALS progression. Impaired DNA repair and protein homeostasis are suggested to be central downstream mechanisms in ALS pathogenesis. Ultimately, understanding the interplay between these pathways could offer novel insights into ALS and provide potential therapeutic targets. This review aims to highlight the emerging connections between protein aggregation, DNA damage repair, and cellular dysfunction in ALS, fostering a deeper understanding of its molecular basis and potential avenues for intervention.

Amyotrophic lateral sclerosis (ALS) is a neurodegenerative disease characterized by the selective loss of motor neurons. Although multiple pathophysiological mechanisms have been identified, a unified molecular basis for ALS has remained elusive. The ALS-associated RNA binding protein (RBP) TDP-43 has previously been shown to stabilize UNC13A mRNA by preventing cryptic exon inclusion. We here show that three ALS-associated RBPs—MATR3, FUS, and hnRNPA1—regulate UNC13A expression by targeting the silencing transcription factor REST. These three RBPs bind to and downregulate REST mRNA and thereby promote UNC13A transcription. REST overexpression was detected not only in response to the loss of each of these three RBPs in cultured cells but also in motor neurons of individuals with familial or sporadic ALS. The functional convergence of four RBPs on the regulation of UNC13A , a gene essential for synaptic transmission, highlights a pivotal contribution of these proteins to maitainance of synaptic integrity. Our findings thus provide key insight into ALS pathogenesis and a basis for the development of new therapeutic agents.