翻訳と辞書 Words near each other ・ Protein inhibitor of activated STAT ・ Protein inhibitor of activated STAT2 ・ Protein isoform ・ Protein K ・ Protein K (gene expression) ・ Protein K (porin) ・ Protein kinase ・ Protein kinase A ・ Protein kinase B ・ Protein kinase C ・ Protein kinase C zeta type ・ Protein kinase D1 ・ Protein kinase domain ・ Protein kinase inhibitor ・ Protein kinase N1 ・ Protein kinase R ・ Protein kinase, AMP-activated, alpha 1 ・ Protein L ・ Protein ligand ・ Protein Local Optimization Program ・ Protein losing enteropathy ・ Protein M ・ Protein mass spectrometry ・ Protein metabolism ・ Protein methods ・ Protein methylase I ・ Protein methylation ・ Protein methyltransferase II ・ Protein microarray ・ Protein mimetic Dictionary Lists mini英和辞書 mini和英辞書 Webster 1913 Latin-English FOLDOC Wikipedia English ウィキペディア

翻訳と辞書　辞書検索 [ 開発暫定版 ] スポンサード リンク Protein kinase R ： ウィキペディア英語版 Protein kinase R Protein kinase RNA-activated also known as protein kinase R (PKR), interferon-induced, double-stranded RNA-activated protein kinase, or eukaryotic translation initiation factor 2-alpha kinase 2 (EIF2AK2) is an enzyme that in humans is encoded by the ''EIF2AK2'' gene.〔(【引用サイトリンク】 url = http://www.ncbi.nlm.nih.gov/sites/entrez?db=gene&cmd=retrieve&dopt=default&list_uids=5610&rn=1 )〕 PKR protects against viral infections. == Mechanism of action == Protein kinase-R is activated by double-stranded RNA (dsRNA), the synthesis of which is caused virally. PKR can also be activated by the protein PACT or by heparin. PKR contains an N-terminal dsRNA binding domain (dsRBD) and a C-terminal kinase domain, that gives it pro-apoptotic (cell-killing) functions. The dsRBD consists of two tandem copies of a conserved double stranded RNA binding motif, dsRBM1 and dsRBM2. PKR is induced by interferon in a latent state. Binding to dsRNA is believed to activate PKR by inducing dimerization and subsequent auto-phosphorylation reactions. In situations of viral infection, the dsRNA created by viral replication and gene expression binds to the N-terminal domain, activating the protein. Once active, PKR is able to phosphorylate the eukaryotic translation initiation factor EIF2A. This inhibits further cellular mRNA translation, thereby preventing viral protein synthesis. Since ElF2A is involved in the commonly initiation translation from an AUG codon, the alternative non-AUG initiation takes place instead. An example of mRNAs using non-AUG initiation are mRNAs for the heat shock proteins. Active PKR is also able to mediate the activation of the transcription factor NFkB, by phosphorylating its inhibitory subunit, IkB. Activated NFkB upregulates the expression of Interferon cytokines, which work to spread the antiviral signal locally. Active PKR is also able to activate tumor suppressor PP2A which regulates the cell cycle and the metabolism. Through complex mechanisms, active PKR is also able to induce cellular apoptosis, to prevent further viral spread. 抄文引用元・出典: フリー百科事典『 ウィキペディア（Wikipedia）』 ■ウィキペディアで「Protein kinase R」の詳細全文を読む スポンサード リンク 翻訳と辞書 : 翻訳のためのインターネットリソース Copyright(C) kotoba.ne.jp 1997-2016. All Rights Reserved.