TERRA 长非编码 RNA 在端粒功能和维护中发挥关键作用。它们可以协调端粒染色质重塑，通过端粒酶和同源定向修复调节端粒维持，并参与端粒 DNA 损伤反应。 TERRA 通过碱基配对形成 R 环与染色体末端结合，这是由 RAD51 DNA 重组酶及其伙伴 RAD51AP1 介导的。端粒 R 环干扰复制叉的进展，刺激端粒维持从半保守 DNA 复制向同源定向修复 (HDR) 的转变。后一种机制被缺乏端粒酶（称为 ALT）的癌细胞子集所利用。此外，TERRA 在衰老过程中刺激短端粒的 HDR，延缓细胞衰老。在癌变过程中，当端粒被侵蚀的细胞进入复制危机时，TERRA 会充当信号分子来介导自噬性细胞死亡。版权所有 © 2024 作者。由爱思唯尔有限公司出版。保留所有权利。

TERRA long noncoding RNAs play key roles in telomere function and maintenance. They can orchestrate telomeric chromatin remodeling, regulate telomere maintenance by telomerase and homology-directed repair, and they participate in the telomeric DNA damage response. TERRA associates with chromosome ends through base-pairing forming R-loops, which are mediated by the RAD51 DNA recombinase and its partner RAD51AP1. Telomeric R-loops interfere with replication fork progression, stimulating a switch of telomere maintenance from semiconservative DNA replication to homology-directed repair (HDR). The latter mechanism is exploited by a subset of cancer cells that lack telomerase, referred to as ALT. In addition, TERRA stimulates HDR at short telomeres during aging, delaying cellular senescence. During carcinogenesis, when cells with eroded telomeres enter replicative crisis, TERRA acts as a signaling molecule to mediate autophagic cell death.Copyright © 2024 The Author(s). Published by Elsevier Ltd.. All rights reserved.