假尿嘧啶核苷

假尿嘧啶核苷
	IUPAC名; 5-[(2S,3R,4S,5R)-3,4-Dihydroxy-5-(hydroxymethyl)-oxolan-2-yl]-1H-pyrimidine-2,4-dione
别名	psi-Uridine, 5-Ribosyluracil, beta-D-Pseudouridine, 5-(beta-D-Ribofuranosyl)uracil
识别
CAS号	1445-07-4
PubChem	15047
ChemSpider	14319
SMILES	O=C1N\C=C(/C(=O)N1)[C@@H]2O[C@H](CO)[C@@H](O)[C@H]2O;
InChI	1/C9H12N2O6/c12-2-4-5(13)6(14)7(17-4)3-1-10-9(16)11-8(3)15/h1,4-7,12-14H,2H2,(H2,10,11,15,16)/t4-,5-,6-,7+/m1/s1;
InChIKey	PTJWIQPHWPFNBW-GBNDHIKLBY
ChEBI	17802
性质
化学式	C9H12N2O6
摩尔质量	244.20 g/mol g·mol⁻¹
外观	白色粉末
溶解性（水）	易溶於水
	若非注明，所有数据均出自标准状态（25 ℃，100 kPa）下。

假尿嘧啶核苷（Pseudouridine，簡稱Ψ或Q^[1]）或稱5-核糖尿嘧啶（5-ribosyluracil）、假尿苷，是尿苷（U）的一種同分異構物，有別於尿苷中尿嘧啶以碳－氮鍵（C1-N1）與核糖相連，假尿嘧啶核苷中尿嘧啶和核糖是以碳－碳鍵（C1-C5）連接，故其結構較有彈性^[2]，比尿苷多出了一個可形成氫鍵的位點，且在RNA中產生的重疊效應高於尿苷^[3]。假尿嘧啶核苷最早於1951年發現，為細胞RNA中最常見的修飾，在三域生物中皆有，有A、U、C、G之外的「第五種核苷」之稱^[4]。

假尿嘧啶核苷是細胞中最常見的RNA修飾，是轉錄後修飾的機制之一，在轉錄結束後由假尿苷合成酶（PUS）自尿苷轉化而來，此修飾可能影響RNA的結構、功能、位置與半衰期。mRNA、tRNA、rRNA、snRNA與snoRNA中均有發現假尿嘧啶核苷修飾，在tRNA與rRNA中可穩定RNA的結構，與其轉譯的功能相關^[2]^[5]^[6]；在snRNA中則可促進剪接體對前体信使RNA（英语：pre-mRNA）的切割^[7]；在mRNA中的功能仍不清楚，有研究顯示終止密碼子中的假尿嘧啶核苷可能會造成轉譯連讀（translation readthrough）^[8]。假尿嘧啶核苷還可能被細胞用作識別自身與外來RNA的機制，即RIG-I和蛋白激酶R（英语：Protein kinase R）等先天免疫蛋白可識別不含有假尿嘧啶核苷的病毒RNA而啟動免疫反應^[8]。

參考文獻

^ Hamma, Tomoko; Ferré-D'Amaré, Adrian R. Pseudouridine Synthases. Chemistry & Biology. November 2006, 13 (11): 1125–1135. ISSN 1074-5521. PMID 17113994. doi:10.1016/j.chembiol.2006.09.009.
^ ^2.0 ^2.1 Gray, Michael Charette, Michael W. Pseudouridine in RNA: What, Where, How, and Why. IUBMB Life. 2000-05-01, 49 (5): 341–351. ISSN 1521-6543. PMID 10902565. doi:10.1080/152165400410182.
^ Zhao BS, He C. Pseudouridine in a new era of RNA modifications.. Cell Res. 2015, 25 (2): 153–4. PMC 4650566 . PMID 25367125. doi:10.1038/cr.2014.143.
^ Katherine M. McKenney, Mary Anne T. Rubio, Juan D. Alfonzo. Chapter Two - The Evolution of Substrate Specificity by tRNA Modification Enzymes. The Enzymes 41. 2017: 51-88 [2021-04-23]. doi:10.1016/bs.enz.2017.03.002. （原始内容存档于2021-04-25）.
^ Ge, Junhui; Yu, Yi-Tao. RNA pseudouridylation: new insights into an old modification. Trends in Biochemical Sciences. April 2013, 38 (4): 210–218. ISSN 0968-0004. PMC 3608706 . PMID 23391857. doi:10.1016/j.tibs.2013.01.002.
^ Rintala-Dempsey, Anne C.; Kothe, Ute. Eukaryotic stand-alone pseudouridine synthases – RNA modifying enzymes and emerging regulators of gene expression?. RNA Biology. 2017-01-03, 14 (9): 1185–1196. ISSN 1547-6286. PMC 5699540 . PMID 28045575. doi:10.1080/15476286.2016.1276150.
^ Wu, Guowei; Radwan, Mohamed K.; Xiao, Mu; Adachi, Hironori; Fan, Jason; Yu, Yi-Tao. TheTORsignaling pathway regulates starvation-induced pseudouridylation of yeast U2 snRNA. RNA. 2016-06-07, 22 (8): 1146–1152. ISSN 1355-8382. PMC 4931107 . PMID 27268497. doi:10.1261/rna.056796.116.
^ ^8.0 ^8.1 Borchardt EK, Martinez NM, Gilbert WV. Regulation and Function of RNA Pseudouridylation in Human Cells.. Annu Rev Genet. 2020, 54: 309–336. PMC 8007080 . PMID 32870730. doi:10.1146/annurev-genet-112618-043830.

[:0-1] Hamma, Tomoko; Ferré-D'Amaré, Adrian R. Pseudouridine Synthases. Chemistry & Biology. November 2006, 13 (11): 1125–1135. ISSN 1074-5521. PMID 17113994. doi:10.1016/j.chembiol.2006.09.009.

[:3-2] 2.0 ^2.1 Gray, Michael Charette, Michael W. Pseudouridine in RNA: What, Where, How, and Why. IUBMB Life. 2000-05-01, 49 (5): 341–351. ISSN 1521-6543. PMID 10902565. doi:10.1080/152165400410182.

[pmid25367125-3] Zhao BS, He C. Pseudouridine in a new era of RNA modifications.. Cell Res. 2015, 25 (2): 153–4. PMC 4650566 . PMID 25367125. doi:10.1038/cr.2014.143.

[4] Katherine M. McKenney, Mary Anne T. Rubio, Juan D. Alfonzo. Chapter Two - The Evolution of Substrate Specificity by tRNA Modification Enzymes. The Enzymes 41. 2017: 51-88 [2021-04-23]. doi:10.1016/bs.enz.2017.03.002. （原始内容存档于2021-04-25）.

[5] Ge, Junhui; Yu, Yi-Tao. RNA pseudouridylation: new insights into an old modification. Trends in Biochemical Sciences. April 2013, 38 (4): 210–218. ISSN 0968-0004. PMC 3608706 . PMID 23391857. doi:10.1016/j.tibs.2013.01.002.

[:2-6] Rintala-Dempsey, Anne C.; Kothe, Ute. Eukaryotic stand-alone pseudouridine synthases – RNA modifying enzymes and emerging regulators of gene expression?. RNA Biology. 2017-01-03, 14 (9): 1185–1196. ISSN 1547-6286. PMC 5699540 . PMID 28045575. doi:10.1080/15476286.2016.1276150.

[7] Wu, Guowei; Radwan, Mohamed K.; Xiao, Mu; Adachi, Hironori; Fan, Jason; Yu, Yi-Tao. TheTORsignaling pathway regulates starvation-induced pseudouridylation of yeast U2 snRNA. RNA. 2016-06-07, 22 (8): 1146–1152. ISSN 1355-8382. PMC 4931107 . PMID 27268497. doi:10.1261/rna.056796.116.

[pmid32870730-8] 8.0 ^8.1 Borchardt EK, Martinez NM, Gilbert WV. Regulation and Function of RNA Pseudouridylation in Human Cells.. Annu Rev Genet. 2020, 54: 309–336. PMC 8007080 . PMID 32870730. doi:10.1146/annurev-genet-112618-043830.

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