小 RNA 介导的转录后沉默
中文名称
通路描述
小 RNA 与 RNA 诱导沉默复合体（RISC）的组分一起，转录后抑制 mRNA 的表达（综述：Nowotny and Yang 2009, Chua et al. 2009）。存在两种机制：1) 由含有 Argonaute2（AGO2, EIF2C2）和与靶 mRNA 完全匹配的指导 RNA 的复合物切割靶 RNA；2) 由含有 AGO2 和不完全匹配指导 RNA 的复合物抑制靶 RNA 的翻译，或由含有非核酸内切酶活性 Argonaute（AGO1（EIF2C1）、AGO3（EIF2C3）或 AGO4（EIF2C4））和完全或不完全匹配指导 RNA 的复合物抑制。小干扰 RNA（siRNA）和微 RNA（miRNA）可以在这两种机制中作为指导 RNA。
RNAi 似乎还指导染色质修饰，导致转录基因沉默（综述：Verdel et al. 2009）。
RNAi 似乎还指导染色质修饰，导致转录基因沉默（综述：Verdel et al. 2009）。
英文描述
Post-transcriptional silencing by small RNAs Small RNAs act with components of the RNA-induced silencing complex (RISC) to post-transcriptionally repress expression of mRNAs (reviewed in Nowotny and Yang 2009, Chua et al. 2009). Two mechanisms exist: 1) cleavage of target RNAs by complexes containing Argonaute2 (AGO2, EIF2C2) and a guide RNA that exactly matches the target mRNA and 2) inhibition of translation of target RNAs by complexes containing AGO2 and an inexactly matching guide RNA or by complexes containing a nonendonucleolytic Argonaute (AGO1 (EIF2C1), AGO3 (EIF2C3), or AGO4 (EIF2C4)) and a guide RNA of exact or inexact match. Small interfering RNAs (siRNAs) and microRNAs (miRNAs) can serve as guide RNAs in both types of mechanism.
RNAi also appears to direct chromatin modifications that cause transcriptional gene silencing (reviewed in Verdel et al. 2009).
RNAi also appears to direct chromatin modifications that cause transcriptional gene silencing (reviewed in Verdel et al. 2009).
所含基因
7 个基因