RNASEL binds 2'-5' oligoadenylate

Stable Identifier
Reaction [transition]
Homo sapiens
Related Species
Rotavirus A
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Ribonuclease L (RNASEL) gene encodes an ankyrin (ANK) repeat domain containing dual endoribonuclease-pseudokinase RNase L that functions in the interferon (IFN) antiviral response (Wreschner DH et al. 1982; Zhou A et al.1993; Hassel BA et al. 1993; Huang H et al. 2014; Han Y et al. 2014). Upon activation by viral double-stranded RNA, 5'-triphosphorylated 2'-5'-linked oligoadenylates (2-5A) are synthesized by one of several 2'-5' oligoadenylate synthetases (OAS). The 2-5A binds to monomeric, inactive RNase L causing it to dimerize through the ANK domains (Dong B & Silverman RH 1995; Tanaka N et al. 2004, 2005; Han Y et al., 2012). Activated RNase L cleaves single-stranded viral and cellular RNA, predominantly after UpU and UpA dinucleotides (Floyd-Smith G et al. 1981; Wreschner DH et al. 1981). The triadenylate form of 2-5A is the minimal active molecule, however, longer 2',5'-oligoadenylates retain the ability to activate RNase L (Dong B et al. 1994).

RNase L possesses nine ankyrin repeats (the 9th being incomplete) in the N-terminus, and pseudokinase and nuclease domains in the C-terminus, which is also termed the kinase-extension nuclease (KEN) domain (Hassel BA et al. 1993; Tanaka N et al. 2004; Han Y et al. 2014; Huang H et al. 2014). The monomeric RNase L lacks nucleolytic activity, however, deletion of ankyrin repeats caused constitutive, albeit reduced, ribonuclease activity (Dong B et al. 1997). Crystal structure data indicate that 2-5A binds to the second and fourth ankyrin repeats and the pseudokinase domain (Tanaka N et al. 2004; Huang H et al. 2014; Han Y et al. 2014). These interactions, in conjunction with binding between the pseudokinase domains of the two protomers, mediate dimerization and enzymatic activation within minutes (Huang H et al. 2014; Han Y et al. 2012, 2014). Once active, RNase L cleaves ssRNA, including cellular mRNA and rRNA as well as microbial RNAs. In uninfected cells RNase L interacts with the actin-binding protein filamin A (FLNA) to modulate the actin cytoskeleton and inhibit virus entry into cells (Malathi K et al. 2014; Ezelle HJ et al. 2016). Upon infection and activation of its enzymatic activity by 2-5A, RNase L dissociates from FLNA to mediate its antiviral signaling (Malathi K et al. 2014; Ezelle HJ et al. 2016).

Literature References
PubMed ID Title Journal Year
26760998 The Roles of RNase-L in Antimicrobial Immunity and the Cytoskeleton-Associated Innate Response

Hassel, BA, Malathi, K, Ezelle, HJ

Int J Mol Sci 2016
24578532 Structure of human RNase L reveals the basis for regulated RNA decay in the IFN response

Korennykh, A, Rath, S, Chitrakar, A, Han, Y, Whitney, G, Donovan, J

Science 2014
25352621 RNase L interacts with Filamin A to regulate actin dynamics and barrier function for viral entry

Hassel, BA, Malathi, K, Zeng, C, Ezelle, HJ, Naji, M, Dayal, S, Siddiqui, MA, Zhou, A

MBio 2014
23084743 Innate immune messenger 2-5A tethers human RNase L into active high-order complexes

Korennykh, A, Han, Y, Whitney, G, Donovan, J

Cell Rep 2012
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