open access

https://hdl.handle.net/2115/62919

Evolution of the DEAD box helicase family in chicken : chickens have no DHX9 ortholog

Genetic deficiency of DHX9 in chicken

英語

type I interferon

2015-10

Wiley-Blackwell

Microbiology and immunology

59(10)

633-640

Viral RNA represents a pattern molecule that can be recognized by RNA sensors in innate immunity. Humans and mice possess cytoplasmic DNA/RNA sensors for detecting viral replication. There are a number of DEAD (Asp-Glu-Ala-Asp; DExD/H) box-type helicases in mammals, among which retinoic acid-inducible gene 1 (RIG-I) and melanoma differentiation-associated protein 5 (MDA50) are indispensable for RNA sensing; however, they are functionally supported by a number of sensors that directly bind viral RNA or replicative RNA intermediates to convey signals to RIG-I and MDA5. Some DEAD box helicase members recognize DNA irrespective of the origin. These sensors transmit IFN-inducing signals through adaptors, including mitochondrial antiviral signaling. Viral double-stranded RNAs are reportedly sensed by the helicases DDX1, DDX21, DHX36, DHX9, DDX3, DDX41, LGP2 and DDX60, in addition to RIG-I and MDA5, and induce type I IFNs, thereby blocking viral replication. Humans and mice have all nucleic acid sensors listed here. In the RNA sensing system in chicken, it was found in the present study that most DEAD box helicases are conserved; however, DHX9 is genetically deficient in addition to reported RIG-I. Based on the current genome databases, similar DHX9 deficiency was observed in ducks and several other bird species. Because chicken, but not duck, was found to be deficient in RIG-I, the RNA-sensing system of chicken lacks RIG-I and DHX9 and is thus more fragile than that of duck or mammal. DHX9 may generally compensate for the function of RIG-I and deficiency of DHX9 possibly participates in exacerbations of viral infection such as influenza in chickens.

学術雑誌論文

Accepted Manuscript

This is the peer reviewed version of the following article: Sato, H., Oshiumi, H., Takaki, H., Hikono, H. and Seya, T. (2015), Evolution of the DEAD box helicase family in chicken: chickens have no DHX9 ortholog. Microbiology and Immunology, 59: 633–640., which has been published in final form at http://dx.doi.org/10.1111/1348-0421.12322. This article may be used for non-commercial purposes in accordance with Wiley Terms and Conditions for Self-Archiving.

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