COVID-19 researchGene: RNASEL
Evidence Summary from Illumina curation team (Alison Coffey and Julie Taylor): RNASEL, also known as 2-5A-dependent RNase is a component of the interferon-regulated 2-5A system that functions in the antiviral interferon pathway. Treatment of cells with interferon results in enhanced levels of both 2-5A-dependent RNase and a group of synthetases that produce 5-prime-triphosphorylated, 2-prime,5-prime-oligoadenylates (2-5A) from ATP. The role of the 2-5A system in the control of viral and cellular growth suggests that defects in the 2-5A-dependent RNase gene could result in reduced immunity to virus infections and cancer (Hassel et al., 1993). Several studies aiming to identify a genetic association between RNASEL and viral susceptibility have failed to identified statistically significant SNPs (Yakub et al. 2005; Arredondo et al. 2012). However, there is sufficient experimental evidence, including a mouse model and in-vitro studies that RNASEL is an important contributor in host defence against several viruses (Gusho et al. 2016 (review); Zhou et al. 1997; Panda et al. 2019).
PMID 27595182: Gusho et al. 2016 (review) - RNase L is a unique IFN-regulated endoribonuclease that serves as an important mediator of antiviral innate immunity with possible roles in antibacterial defense and prostate cancer. It is controlled by IFN-inducible oligo-adenylate synthetases (OASs) and double-stranded RNAs (dsRNAs). OAS-RNase L (Fig. 1) pathway, discovered in the mid-1970s, was one of the first IFN-dependent antiviral pathways to be characterized. OASs are IFN-I/-III-inducible genes that are expressed at very low basal levels in many cell types. OASs1-3 act as pathogen recognition receptors that sense dsRNAs and activate the synthesis of 5’-phosphorylated 2’-5’ linked oligoadenylates from ATP (2-5A). 2-5A acts as a second messenger and binds monomeric RNase L, and activates its dimer formation. Active RNase L cleaves cellular and viral RNAs within single-stranded regions. RNA degradation directly and indirectly activates subsequent events, including the elimination of viral genomes, inhibition of cellular and viral protein synthesis; and activation of several cellular signaling pathways, including those involved in autophagy, apoptosis, senescence, IFN-b production, and NLRP3-inflammasome activation as part of its antiviral mechanism (references provided). Authors state that many viruses have evolved or acquired strategies that antagonize the OAS-RNase L pathway to evade antiviral innate immunity. Some, such as Influenza A (IAV), HSV and Vaccinia virus act through an RNA-binding domain which binds to and sequesters dsRNA, the activator of OAS. Others bind directly to monomeric RNase L preventing it from activation by dimerization. Some coronaviruses (MERS-CoV and MHV) are described to act through their ns-domains with 2’-5’ PDE activity that degrades 2-5A and thus prevent activation of RNase L.
Some additional evidence of interest:
-OAS3 was shown to exert antiviral activity against Dengue virus in an RNase L-dependent manner, indicating that OAS3 synthesizes active 2-5A in sufficient amounts for RNase L activation
-RNase L activation by dsRNA signaling or viral infection contributes to IFN-b production, indicating its important role in innate immunity. The ribonuclease function of RNase L is essential for its effect on IFN-b production
-Moreover, mice deficient in RNase L had several-fold reduced levels of IFN-b induction after infection with RNA viruses (EMCV and Sendai virus)
-Stable expression of wild-type human full-length RNase L, but not ribonuclease dead mutant (R667A), activates IL-1b and caspase 1 secretion in RNase L-deficient THP1 cells after virus infection or 2-5A transfection
PMID 9351818: Zhou et al. (1997) RNASEL Mouse model
To determine the physiological roles of the 2-5A system, mice were generated with a targeted disruption of the RNase L gene. The antiviral effect of interferon was impaired in RNaseL–/– mice providing the first evidence that the 2-5A system functions as an antiviral pathway in animals. Authors showed that EMCV replicates more efficiently in cells lacking RNase L than in wild type cells, even after interferon treatment, although the effect is relatively small. Next, authors determined that survival of RNaseL-/- mice after EMCV infection was significantly reduced both in presence and absence of IF (Fig 3). Enlarged thymus and reduced level of apoptosis in thymus and spleen were also found (Fig 4-5).
PMID 31156620 Panda et al (2019)
Interferon regulatory factor-1 (IRF1) regulates expression of RNaseL and knockdown of RNaseL in BEAS-2B cells resulted in significantly increased VSV infection rates. (Fig.6)
PMID 22356654 Arredondo et al. 2012
Authors studied allelic variants in RNASEL gene at codon 462 (R462Q, rs486907) for susceptibility to viral infection, prostate cancer and chronic fatigue syndrome. The allelic distribution at codon 462 was 139 (33.9%), 204 (49.8%), and 67 (16.3%) for RR, RQ, and QQ, respectively, in 410 individuals in Spain. There were no significant differences comparing 105 blood donors and 71 patients with HIV-1 infection, 27 with chronic hepatitis C, 67 with prostate cancer, and 107 with chronic fatigue syndrome. In contrast, two-thirds of 18 patients with HTLV-1 infection and 15 with chronic hepatitis B harbored RR (Table 1). Thus, polymorphisms at the RNASEL gene do not seem to influence the susceptibility to common viral infections or conditions potentially of viral etiology. They conclude that the role in influencing the susceptibility to HTLV-1 or HBV chronic infection warrants further examination in larger patient populations.
Created: 28 May 2020, 3:27 p.m. | Last Modified: 28 May 2020, 3:27 p.m.
Panel Version: 0.349
Identified through an OMIM search for potential viral susceptibility genes, and subsequently triaged/reviewed by Illumina curation team.
Created: 28 May 2020, 12:36 p.m. | Last Modified: 28 May 2020, 12:36 p.m.
Panel Version: 0.336
gene: RNASEL was added gene: RNASEL was added to COVID-19 research. Sources: Expert list,OMIM,Expert Review Green Mode of inheritance for gene: RNASEL was set to Unknown