环素A向TRIM5的逆转换解释了猫头对HIV-1的抗性
David M Sayah1, Elena Sokolskaja, Lionel Berthoux
1Department of Microbiology, Columbia University, College of Physicians and Surgeons, 701 West 168th Street, HHSC 1502 New York, New York 10032, USA.
Nature
|July 10, 2004
概括
猫头通过TRIMCyp,一种融合蛋白质来限制人类免疫缺陷病毒1型 (HIV-1). 这种抗病毒TRIMCyp基因源于LINE-1逆转移子将环素A (CypA) DNA插入TRIM5基因.
科学领域:
- 病毒学 病毒学
- 遗传学 是一个遗传学.
- 进化生物学 进化生物学
背景情况:
- 旧世界灵长类动物拥有TRIM5-alpha,抑制人类免疫缺陷病毒1型 (HIV-1) 进入后.
- 结合病毒囊的环素A (CypA) 通常可以保护HIV-1免受人类细胞的限制.
- 猫头在新世界灵长类动物中是独一无二的,因为它们表现出HIV-1的入境后限制.
研究的目的:
- 为了研究猫头入境后限制HIV-1的机制.
- 为了确定负责这种抗病毒活性的特定遗传因素.
- 为了理解这种灵长类特异性防御的进化起源.
主要方法:
- 使用RNA干扰 (RNAi) 来降低猫头的环素A (CypA).
- 在接受治疗的细胞中重新引入CypA蛋白.
- 对额外的RNAi目标的查确定了TRIMCyp.
- 用人类和老鼠细胞进行基因转移实验.
主要成果:
- 淘汰猫头CypA与减少的抗HIV-1活性相关,但重新引入并没有恢复它.
- 确定TRIMCyp,TRIM5-CypA融合蛋白,是导致入境后限制的原因.
- 当转移到人类和老鼠细胞时,TRIMCyp 赋予了HIV-1 限制.
- TRIMCyp基因可能源于LINE-1逆转移素介导的CypAcDNA插入TRIM5位点.
结论:
- 在猫头中,TRIMCyp是进入后HIV-1限制的关键媒介.
- 这种基因代表了一种新的进化机制,其中一个逆转移子促进了脊椎动物的外子混合.
- 在不同物种中,TRIMCyp能够阻止HIV-1感染,这突显了其强大的抗病毒功能.
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