从人类氨基酸-tRNA合成酶中释放的两个不同的细胞因子
1The Skaggs Institute for Chemical Biology, The Scripps Research Institute, Beckman Center, 10550 North Torrey Pines Road, La Jolla, CA 92037, USA.
概括
人类氨基-tRNA合成酶分裂成两个细胞因子活性片段. 这些在亡过程中产生的碎片表现出强大的白细胞和单细胞激活功能,影响细胞过程.
科学领域:
- 生物化学 生物化学
- 分子生物学分子生物学
- 免疫学 免疫学 免疫学
背景情况:
- 氨基酸-tRNA合成酶是蛋白质合成的关键酶,催化氨基酸与它们的同源转移RNA (tRNA) 的附着.
- 新出现的证据表明,这些酶的非正规功能超出了它们的催化作用.
研究的目的:
- 为了研究人类氨基-tRNA合成酶的潜在细胞因子类活性.
- 为了确定tRNA合成酶的不同片段的功能性质.
主要方法:
- 人类铁酸-tRNA合成酶的生物化学碎片化.
- 对白细胞和单细胞化学反应的测定.
- 测量骨髓氧化酶,瘤亡因子-α和组织因子的产生.
- 对联蛋白-8型A受体的结合的分析.
- 在亡条件下进行细胞培养实验.
主要成果:
- 人类氨基-tRNA合成酶可以分裂成两个具有明显细胞因子活动的碎片.
- 碳氧终端域表现出内皮单细胞激活多II类活性,促进白细胞和单细胞化学反应,刺激炎症介质的产生.
- 氨基终端域结合于INTERLEUKIN-8型A受体,作为一种类似INTERLEUKIN-8的细胞因子起作用.
- 在亡条件下,全长的酶被白细胞弹性酶分泌和分裂成这些活性细胞因子碎片.
结论:
- 人类氨基-tRNA合成酶具有由其独特的域介导的双细胞因子活动.
- 在亡过程中分泌和碎片化tRNA合成酶的分泌和碎片化可能会通过阻止翻译和产生炎症性细胞因子,促进亡过程.
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One of the unique features of tRNA is the presence of modified bases. In some tRNAs, modified bases account for nearly 20% of the total bases in the molecule. Altogether, these unusual bases protect the tRNA from enzymatic degradation by RNases.
Each of these chemical modifications is carried by a specific enzyme, post-transcription. All of these enzymes have unique base and site-specificity. Methylation, the most common chemical modification, is carried by at least nine different enzymes, with...
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