DDX60 (DEAD-Box Helicase 60) is an RNA helicase involved in antiviral immunity and RNA metabolism. It acts as a cofactor for RIG-I signaling and is important for the cellular response to viral infection. DDX60 belongs to the DEAD-box helicase family, characterized by the conserved Asp-Glu-Ala-Asp motif, and plays roles in both innate immunity and RNA processing.
| Symbol | DDX60 |
|---|---|
| Full Name | DEAD-Box Helicase 60 |
| Aliases | LRR51, DDX60L, RHIV-1 |
| Chromosomal Location | Chr4q33 |
| NCBII Gene ID | 55626 |
| Protein Class | DEAD-box RNA helicase |
DDX60 is a large RNA helicase with multiple functional domains:
DDX60 participates in several cellular processes:
Antiviral Immunity: DDX60 is a key component of the RIG-I signaling pathway. It interacts with RIG-I (DDX58) and MDA5 (IFIH1) to enhance antiviral responses against RNA viruses. DDX60 promotes the phosphorylation of IRF3 and IRF7, leading to type I interferon production. [3]
RNA Processing: DDX60 is involved in various aspects of RNA metabolism, including:
DNA Damage Response: Recent studies suggest DDX60 may play a role in the DNA damage response, though this function is less characterized. [4]
DDX60 has emerged as a relevant player in Alzheimer's disease pathogenesis:
Viral Defense Hypothesis: DDX60's antiviral function intersects with the viral hypothesis of AD. Herpes simplex virus type 1 (HSV-1) has been implicated in AD pathogenesis, and DDX60-mediated antiviral responses may influence this relationship. The balance between viral detection and inflammatory responses could affect amyloid-beta deposition and tau pathology. [5]
Interferon Signaling: Chronic activation of interferon signaling has been observed in AD brains. DDX60 is involved in interferon-stimulated gene (ISG) regulation, and dysregulation of this pathway may contribute to neuroinflammation and neuronal dysfunction. [6]
RNA Metabolism Defects: AD is characterized by widespread RNA processing abnormalities, including altered splicing and mRNA translation. DDX60's role in RNA metabolism suggests it may contribute to these defects. [7]
Neuroinflammation: DDX60 expression is upregulated in inflammatory conditions. In PD, chronic neuroinflammation driven by microglial activation contributes to dopaminergic neuron death. DDX60-mediated pathways may modulate this inflammatory response. [8]
Viral Susceptibility: Certain viruses have been proposed as environmental triggers for PD. DDX60's antiviral function could influence susceptibility to virus-triggered parkinsonism. [9]
Mitochondrial RNA Processing: DDX60 may interact with mitochondrial RNA processing pathways. Mitochondrial dysfunction is central to PD pathogenesis, and any contribution from RNA metabolism defects could be relevant. [10]
Antiviral Responses in ALS: Elevated interferon signatures have been reported in ALS patients and models. DDX60, as an interferon-stimulated gene, may be part of this dysregulated antiviral-like response. [11]
RNA Metabolism and TDP-43: ALS is characterized by cytoplasmic TDP-43 inclusions, reflecting disrupted RNA metabolism. DDX60's involvement in RNA processing positions it to potentially interact with or compensate for TDP-43 dysfunction. [12]
Stress Granule Formation: DDX60 may participate in stress granule formation, which is altered in ALS. Stress granules are cytoplasmic aggregates that form in response to cellular stress and are relevant to ALS pathogenesis. [13]
Viral Trigger Hypothesis: MS is thought to involve viral triggers, including Epstein-Barr virus (EBV). DDX60's antiviral function may influence susceptibility to EBV-associated demyelination. [14]
Interferon Therapy Response: Interferon-beta is used to treat MS. DDX60 is an interferon-stimulated gene, and its expression may influence treatment response. [15]
Targeting DDX60 pathways presents therapeutic opportunities:
| Protein | Interaction Type | Function |
|---|---|---|
| RIG-I (DDX58) | Direct interaction | Antiviral signaling |
| MDA5 (IFIH1) | Direct interaction | Antiviral signaling |
| IKKε | Kinase substrate | IRF3/7 phosphorylation |
| TBK1 | Kinase | Signaling downstream of RIG-I |
| IRF3 | Transcription factor | Type I interferon induction |
| OASL | Co-factor | Antiviral effector |
DDX60 is an RNA helicase with important roles in antiviral immunity and RNA metabolism. Its involvement in interferon-stimulated gene pathways connects it to neuroinflammation in Alzheimer's disease, Parkinson's disease, and ALS. The viral defense functions of DDX60 may be particularly relevant given the proposed viral triggers for several neurodegenerative conditions. Understanding DDX60's role in neurodegeneration may lead to novel therapeutic approaches targeting antiviral immunity and neuroinflammation.
Fairman-Williams et al. DEAD-box helicase family (2010). 2010. ↩︎
Moy et al. LRR domains in protein interactions (2009). 2009. ↩︎
Sohda et al. DDX60 and RIG-I signaling (2015). 2015. ↩︎
Jankowsky & Harris, RNA helicases in DNA repair (2015). 2015. ↩︎
Itzhaki et al. Herpes simplex virus and AD (2016). 2016. ↩︎
Lam et al. Interferon signatures in AD (2019). 2019. ↩︎
Liu et al. RNA metabolism defects in AD (2017). 2017. ↩︎
Lassmann et al. Neuroinflammation in PD (2012). 2012. ↩︎
Wang et al. Interferon signatures in ALS (2018). 2018. ↩︎
Rademakers & Rovelet-Lecrux, TDP-43 in neurodegeneration (2009). 2009. ↩︎
Fitzgerald et al. Interferon-beta therapy in MS (2015). 2015. ↩︎