{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2026,10,3]],"date-time":"2026-10-03T22:13:32Z","timestamp":1791065612191,"version":"4.1.0"},"reference-count":21,"publisher":"National Academy of Sciences","issue":"44","content-domain":{"domain":["www.pnas.org"],"crossmark-restriction":true},"short-container-title":["Proc. Natl. Acad. Sci. U.S.A."],"published-print":{"date-parts":[[2008,11,4]]},"abstract":"<jats:p>As part of the mammalian cell innate immune response, the double-stranded RNA activated protein kinase PKR phosphorylates the translation initiation factor eIF2\u03b1 to inhibit protein synthesis and thus block viral replication. Poxviruses including vaccinia and smallpox viruses express PKR inhibitors such as the vaccinia virus K3L protein that resembles the N-terminal substrate-targeting domain of eIF2\u03b1. Whereas high-level expression of human PKR was toxic in yeast, this growth inhibition was suppressed by coexpression of the K3L protein. We used this yeast assay to screen for PKR mutants that are resistant to K3L inhibition, and we identified 12 mutations mapping to the C-terminal lobe of the PKR kinase domain. The PKR mutations specifically conferred resistance to the K3L protein both in yeast and in vitro. Consistently, the PKR-D486V mutation led to nearly a 15-fold decrease in K3L binding affinity yet did not impair eIF2\u03b1 phosphorylation. Our results support the identification of the eIF2\u03b1-binding site on an extensive face of the C-terminal lobe of the kinase domain, and they indicate that subtle changes to the PKR kinase domain can drastically impact pseudosubstrate inhibition while leaving substrate phosphorylation intact. We propose that these paradoxical effects of the PKR mutations on pseudosubstrate vs. substrate interactions reflect differences between the rigid K3L protein and the plastic nature of eIF2\u03b1 around the Ser-51 phosphorylation site.<\/jats:p>","DOI":"10.1073\/pnas.0805524105","type":"journal-article","created":{"date-parts":[[2008,10,29]],"date-time":"2008-10-29T21:09:33Z","timestamp":1225314573000},"page":"16894-16899","update-policy":"https:\/\/doi.org\/10.1073\/pnas.cm10313","source":"Crossref","is-referenced-by-count":40,"title":["Protein kinase PKR mutants resistant to the poxvirus pseudosubstrate K3L protein"],"prefix":"10.1073","volume":"105","author":[{"given":"Eun Joo","family":"Seo","sequence":"first","affiliation":[{"name":"Laboratory of Gene Regulation and Development, Eunice Kennedy Shriver National Institute of Child Health and Human Development, National Institutes of Health, Bethesda, MD 20892;"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Furong","family":"Liu","sequence":"additional","affiliation":[{"name":"Laboratory of Gene Regulation and Development, Eunice Kennedy Shriver National Institute of Child Health and Human Development, National Institutes of Health, Bethesda, MD 20892;"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Makiko","family":"Kawagishi-Kobayashi","sequence":"additional","affiliation":[{"name":"Laboratory of Gene Regulation and Development, Eunice Kennedy Shriver National Institute of Child Health and Human Development, National Institutes of Health, Bethesda, MD 20892;"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Tekly L.","family":"Ung","sequence":"additional","affiliation":[{"name":"Laboratory of Gene Regulation and Development, Eunice Kennedy Shriver National Institute of Child Health and Human Development, National Institutes of Health, Bethesda, MD 20892;"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Chune","family":"Cao","sequence":"additional","affiliation":[{"name":"Laboratory of Gene Regulation and Development, Eunice Kennedy Shriver National Institute of Child Health and Human Development, National Institutes of Health, Bethesda, MD 20892;"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Arvin C.","family":"Dar","sequence":"additional","affiliation":[{"name":"Program in Systems Biology, Samuel Lunenfeld Research Institute, Mount Sinai Hospital, Toronto, ON, Canada M5G 1X5; and"},{"name":"Department of Molecular Genetics, University of Toronto, Toronto, ON, Canada M5S 1A8"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Frank","family":"Sicheri","sequence":"additional","affiliation":[{"name":"Program in Systems Biology, Samuel Lunenfeld Research Institute, Mount Sinai Hospital, Toronto, ON, Canada M5G 1X5; and"},{"name":"Department of Molecular Genetics, University of Toronto, Toronto, ON, Canada M5S 1A8"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Thomas E.","family":"Dever","sequence":"additional","affiliation":[{"name":"Laboratory of Gene Regulation and Development, Eunice Kennedy Shriver National Institute of Child Health and Human Development, National Institutes of Health, Bethesda, MD 20892;"}],"role":[{"vocabulary":"crossref","role":"author"}]}],"member":"341","published-online":{"date-parts":[[2008,11,4]]},"reference":[{"key":"e_1_3_3_1_2","doi-asserted-by":"publisher","DOI":"10.1128\/JVI.78.1.197-205.2004"},{"key":"e_1_3_3_2_2","doi-asserted-by":"publisher","DOI":"10.1016\/S0163-7258(97)00165-4"},{"key":"e_1_3_3_3_2","first-page":"545","volume-title":"Translational Control in Biology and Medicine","author":"Mohr IJ","year":"2007","unstructured":"IJ Mohr, T Pe'ery, MB Mathews Translational Control in Biology and Medicine, eds MB Mathews, N Sonenberg, JWB Hershey (Cold Spring Harbor Lab Press, Cold Spring Harbor, MS), pp. 545\u2013599 (2007)."},{"key":"e_1_3_3_4_2","doi-asserted-by":"publisher","DOI":"10.1016\/S1097-2765(02)00590-7"},{"key":"e_1_3_3_5_2","doi-asserted-by":"publisher","DOI":"10.1016\/S0022-2836(02)00858-6"},{"key":"e_1_3_3_6_2","doi-asserted-by":"publisher","DOI":"10.1128\/jvi.66.4.1943-1950.1992"},{"key":"e_1_3_3_7_2","doi-asserted-by":"publisher","DOI":"10.1016\/S0021-9258(18)31463-7"},{"key":"e_1_3_3_8_2","doi-asserted-by":"publisher","DOI":"10.1074\/jbc.271.40.24526"},{"key":"e_1_3_3_9_2","doi-asserted-by":"publisher","DOI":"10.1016\/j.cell.2005.06.041"},{"key":"e_1_3_3_10_2","doi-asserted-by":"publisher","DOI":"10.1128\/MCB.16.8.4172"},{"key":"e_1_3_3_11_2","doi-asserted-by":"publisher","DOI":"10.1111\/j.1432-1033.1997.00085.x"},{"key":"e_1_3_3_12_2","doi-asserted-by":"publisher","DOI":"10.1016\/j.cell.2005.06.044"},{"key":"e_1_3_3_13_2","doi-asserted-by":"publisher","DOI":"10.1002\/j.1460-2075.1992.tb05200.x"},{"key":"e_1_3_3_14_2","doi-asserted-by":"publisher","DOI":"10.1073\/pnas.90.10.4616"},{"key":"e_1_3_3_15_2","doi-asserted-by":"publisher","DOI":"10.1128\/MCB.15.1.365"},{"key":"e_1_3_3_16_2","doi-asserted-by":"publisher","DOI":"10.1006\/viro.2000.0561"},{"key":"e_1_3_3_17_2","doi-asserted-by":"publisher","DOI":"10.1128\/MCB.17.7.4146"},{"key":"e_1_3_3_18_2","doi-asserted-by":"publisher","DOI":"10.1016\/j.jmb.2003.09.045"},{"key":"e_1_3_3_19_2","doi-asserted-by":"publisher","DOI":"10.1074\/jbc.M111804200"},{"key":"e_1_3_3_20_2","doi-asserted-by":"publisher","DOI":"10.1093\/genetics\/117.3.409"},{"key":"e_1_3_3_21_2","doi-asserted-by":"publisher","DOI":"10.1093\/emboj\/20.14.3728"}],"container-title":["Proceedings of the National Academy of Sciences"],"original-title":[],"language":"en","link":[{"URL":"https:\/\/pnas.org\/doi\/pdf\/10.1073\/pnas.0805524105","content-type":"unspecified","content-version":"vor","intended-application":"similarity-checking"}],"deposited":{"date-parts":[[2022,4,12]],"date-time":"2022-04-12T18:09:26Z","timestamp":1649786966000},"score":1,"resource":{"primary":{"URL":"https:\/\/pnas.org\/doi\/full\/10.1073\/pnas.0805524105"}},"subtitle":[],"short-title":[],"issued":{"date-parts":[[2008,11,4]]},"references-count":21,"journal-issue":{"issue":"44","published-print":{"date-parts":[[2008,11,4]]}},"alternative-id":["10.1073\/pnas.0805524105"],"URL":"https:\/\/doi.org\/10.1073\/pnas.0805524105","relation":{},"ISSN":["0027-8424","1091-6490"],"issn-type":[{"value":"0027-8424","type":"print"},{"value":"1091-6490","type":"electronic"}],"subject":[],"published":{"date-parts":[[2008,11,4]]},"assertion":[{"value":"2008-06-10","order":0,"name":"received","label":"Received","group":{"name":"publication_history","label":"Publication History"}},{"value":"2008-11-04","order":2,"name":"published","label":"Published","group":{"name":"publication_history","label":"Publication History"}}]}}