Human genome-wide RNAi screen identifies an essential role for inositol pyrophosphates in type-I interferon response
The pattern recognition receptor RIG-I is critical for Type-I interferon production. However, the global regulation of RIG-I signaling is only partially understood. Using a human genome-wide RNAi-screen, we identified 226 novel regulatory proteins of RIG-I mediated interferon-β production. Furthermo...
| Main Authors: | , , , , , , , , , , , , , , , |
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| Format: | Journal article |
| Language: | English |
| Published: |
PLoS
2014
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| _version_ | 1797097409095925760 |
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| author | Pulloor, N Nair, S Kostic, A Bist, P Weaver, J Riley, A Tyagi, R Uchil, P York, J Snyder, S García-Sastre, A Potter, B Lin, R Shears, S Xavier, R Krishnan, M |
| author_facet | Pulloor, N Nair, S Kostic, A Bist, P Weaver, J Riley, A Tyagi, R Uchil, P York, J Snyder, S García-Sastre, A Potter, B Lin, R Shears, S Xavier, R Krishnan, M |
| author_sort | Pulloor, N |
| collection | OXFORD |
| description | The pattern recognition receptor RIG-I is critical for Type-I interferon production. However, the global regulation of RIG-I signaling is only partially understood. Using a human genome-wide RNAi-screen, we identified 226 novel regulatory proteins of RIG-I mediated interferon-β production. Furthermore, the screen identified a metabolic pathway that synthesizes the inositol pyrophosphate 1-IP7 as a previously unrecognized positive regulator of interferon production. Detailed genetic and biochemical experiments demonstrated that the kinase activities of IPPK, PPIP5K1 and PPIP5K2 (which convert IP5 to1-IP7) were critical for both interferon induction, and the control of cellular infection by Sendai and influenza A viruses. Conversely, ectopically expressed inositol pyrophosphate-hydrolases DIPPs attenuated interferon transcription. Mechanistic experiments in intact cells revealed that the expression of IPPK, PPIP5K1 and PPIP5K2 was needed for the phosphorylation and activation of IRF3, a transcription factor for interferon. The addition of purified individual inositol pyrophosphates to a cell free reconstituted RIG-I signaling assay further identified 1-IP7 as an essential component required for IRF3 activation. The inositol pyrophosphate may act by β-phosphoryl transfer, since its action was not recapitulated by a synthetic phosphonoacetate analogue of 1-IP7. This study thus identified several novel regulators of RIG-I, and a new role for inositol pyrophosphates in augmenting innate immune responses to viral infection that may have therapeutic applications. |
| first_indexed | 2024-03-07T04:55:05Z |
| format | Journal article |
| id | oxford-uuid:d650fcb1-4ebf-416d-ae76-ab86373634ae |
| institution | University of Oxford |
| language | English |
| last_indexed | 2024-03-07T04:55:05Z |
| publishDate | 2014 |
| publisher | PLoS |
| record_format | dspace |
| spelling | oxford-uuid:d650fcb1-4ebf-416d-ae76-ab86373634ae2022-03-27T08:32:40ZHuman genome-wide RNAi screen identifies an essential role for inositol pyrophosphates in type-I interferon responseJournal articlehttp://purl.org/coar/resource_type/c_dcae04bcuuid:d650fcb1-4ebf-416d-ae76-ab86373634aeEnglishSymplectic Elements at OxfordPLoS2014Pulloor, NNair, SKostic, ABist, PWeaver, JRiley, ATyagi, RUchil, PYork, JSnyder, SGarcía-Sastre, APotter, BLin, RShears, SXavier, RKrishnan, MThe pattern recognition receptor RIG-I is critical for Type-I interferon production. However, the global regulation of RIG-I signaling is only partially understood. Using a human genome-wide RNAi-screen, we identified 226 novel regulatory proteins of RIG-I mediated interferon-β production. Furthermore, the screen identified a metabolic pathway that synthesizes the inositol pyrophosphate 1-IP7 as a previously unrecognized positive regulator of interferon production. Detailed genetic and biochemical experiments demonstrated that the kinase activities of IPPK, PPIP5K1 and PPIP5K2 (which convert IP5 to1-IP7) were critical for both interferon induction, and the control of cellular infection by Sendai and influenza A viruses. Conversely, ectopically expressed inositol pyrophosphate-hydrolases DIPPs attenuated interferon transcription. Mechanistic experiments in intact cells revealed that the expression of IPPK, PPIP5K1 and PPIP5K2 was needed for the phosphorylation and activation of IRF3, a transcription factor for interferon. The addition of purified individual inositol pyrophosphates to a cell free reconstituted RIG-I signaling assay further identified 1-IP7 as an essential component required for IRF3 activation. The inositol pyrophosphate may act by β-phosphoryl transfer, since its action was not recapitulated by a synthetic phosphonoacetate analogue of 1-IP7. This study thus identified several novel regulators of RIG-I, and a new role for inositol pyrophosphates in augmenting innate immune responses to viral infection that may have therapeutic applications. |
| spellingShingle | Pulloor, N Nair, S Kostic, A Bist, P Weaver, J Riley, A Tyagi, R Uchil, P York, J Snyder, S García-Sastre, A Potter, B Lin, R Shears, S Xavier, R Krishnan, M Human genome-wide RNAi screen identifies an essential role for inositol pyrophosphates in type-I interferon response |
| title | Human genome-wide RNAi screen identifies an essential role for inositol pyrophosphates in type-I interferon response |
| title_full | Human genome-wide RNAi screen identifies an essential role for inositol pyrophosphates in type-I interferon response |
| title_fullStr | Human genome-wide RNAi screen identifies an essential role for inositol pyrophosphates in type-I interferon response |
| title_full_unstemmed | Human genome-wide RNAi screen identifies an essential role for inositol pyrophosphates in type-I interferon response |
| title_short | Human genome-wide RNAi screen identifies an essential role for inositol pyrophosphates in type-I interferon response |
| title_sort | human genome wide rnai screen identifies an essential role for inositol pyrophosphates in type i interferon response |
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