核小核糖核蛋白

核小核糖核蛋白（英文：small nuclear ribonucleoproteins，簡稱snRNP）是一種大型RNA-蛋白質複合物，其與未修飾的mRNA前體(pre-mRNA)和各種其他蛋白質結合形成剪接體，功能是mRNA前體的剪接。snRNP的參與對於去除mRNA前體中的內含子至關重要，僅發生在真核細胞核中RNA轉錄後修飾的其中一部分。另外，snRNP的變體-U7 snRNP並不參與剪接，其僅負責處理組蛋白mRNA前體的3'端。^[1]

結構

snRNP由蛋白質分子和RNA所組成，而在每個snRNP顆粒中發現的RNA則稱為小核RNA（snRNA），通常長度約為150個核苷酸。snRNP的snRNA成分是藉著“識別”內含子的5'和3'末端以及分支位點(branch site)的關鍵剪接信號序列來賦予單個內含子的特異性。snRNP中的snRNA與核醣體RNA相似，因其直接結合酶促反應和結構作用。^[2]

發現

SnRNPs是由Michael R. Lerner和Joan A. Steitz發現的^[3]^[4]。Thomas R. Cech和Sidney Altman也發現到RNA可以在細胞發育中扮演催化劑的作用，故在1989年獲得諾貝爾化學獎。^[5]

參考資料

^ Schümperli, D.; R. S. Pillai. The special Sm core structure of the U7 snRNP: far-reaching significance of a small nuclear ribonucleoprotein (PDF). Cellular and Molecular Life Sciences. 2004-10-01, 61 (19–20): 2560–2570 [2021-04-17]. ISSN 1420-682X. PMID 15526162. doi:10.1007/s00018-004-4190-0. （原始内容存档 (PDF)于2019-04-28）.
^ SnRNP. ScienceDirect Topics. [2024-12-12] （英语）.
^ Lerner MR, Steitz JA. Antibodies to small nuclear RNAs complexed with proteins are produced by patients with systemic lupus erythematosus. Proc. Natl. Acad. Sci. U.S.A. November 1979, 76 (11): 5495–9. Bibcode:1979PNAS...76.5495R. PMC 411675 . PMID 316537. doi:10.1073/pnas.76.11.5495.
^ Lerner MR, Boyle JA, Mount SM, Wolin SL, Steitz JA. Are snRNPs involved in splicing?. Nature. January 1980, 283 (5743): 220–4. Bibcode:1980Natur.283..220L. PMID 7350545. doi:10.1038/283220a0.
^ The Nobel Prize in Chemistry 1989. NobelPrize. [2024-12-12] （英语）.

外部連結

Joan Steitz's Short Talk: "SNURPs and Serendipity" （英文）（页面存档备份，存于互联网档案馆）
醫學主題詞表（MeSH）：snRNP（英文）

[U7_snRNP-1] Schümperli, D.; R. S. Pillai. The special Sm core structure of the U7 snRNP: far-reaching significance of a small nuclear ribonucleoprotein (PDF). Cellular and Molecular Life Sciences. 2004-10-01, 61 (19–20): 2560–2570 [2021-04-17]. ISSN 1420-682X. PMID 15526162. doi:10.1007/s00018-004-4190-0. （原始内容存档 (PDF)于2019-04-28）.

[2] SnRNP. ScienceDirect Topics. [2024-12-12] （英语）.

[3] Lerner MR, Steitz JA. Antibodies to small nuclear RNAs complexed with proteins are produced by patients with systemic lupus erythematosus. Proc. Natl. Acad. Sci. U.S.A. November 1979, 76 (11): 5495–9. Bibcode:1979PNAS...76.5495R. PMC 411675 . PMID 316537. doi:10.1073/pnas.76.11.5495.

[4] Lerner MR, Boyle JA, Mount SM, Wolin SL, Steitz JA. Are snRNPs involved in splicing?. Nature. January 1980, 283 (5743): 220–4. Bibcode:1980Natur.283..220L. PMID 7350545. doi:10.1038/283220a0.

[5] The Nobel Prize in Chemistry 1989. NobelPrize. [2024-12-12] （英语）.

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