Génétique, Reproduction et Développement, UMR CNRS - Clermont Université - INSERM U, UFR Sciences et Technologies, Université Blaise Pascal, Aubière, France.
Curr Protein Pept Sci. 2011 Mar;12(2):84-92. doi: 10.2174/138920311795684931.
Repair of DNA damage is essential for the maintenance of the integrity and transmission of the genome in development and reproduction. Telomeres are nucleoprotein structures which protect the ends of (linear) eukaryotic chromosomes. Telomere dysfunction results in loss of this protection and the telomeres being recognised as DNA damage by the cellular DNA Damage Repair and Response (DDR) machinery, leading to senescence or cell death. Telomeric homeostasis is thus tightly controlled and many specific and non-specific proteins are involved in its regulation. Among these, DNA damage and Repair proteins contribute both to the recognition of telomere dysfunction and more surprisingly, are directly implicated in telomere homeostasis itself. Plants offer a great opportunity to study these mechanisms due to the fact that many key DNA repair and recombination proteins are non-essential in plants, in contrast to vertebrates. In the following text, after a brief summary of the current state of knowledge on telomere-specific proteins in plants, we review the DDR processes and the related proteins implicated in plant telomere stability. We focus specifically on telomere signalling and on recombination events induced by unprotected telomeres, at the origin of genome rearrangements and instability when telomere function is affected.
DNA 损伤的修复对于基因组的完整性和在发育和生殖过程中的传递至关重要。端粒是保护（线性）真核染色体末端的核蛋白结构。端粒功能障碍导致这种保护的丧失，并且端粒被细胞 DNA 损伤修复和反应 (DDR) 机制识别为 DNA 损伤，导致衰老或细胞死亡。因此，端粒稳态受到严格控制，许多特定和非特定的蛋白质参与其调节。在这些蛋白质中，DNA 损伤和修复蛋白不仅有助于识别端粒功能障碍，而且更令人惊讶的是，它们直接参与端粒稳态本身。由于许多关键的 DNA 修复和重组蛋白在植物中是非必需的，与脊椎动物形成对比，因此植物为研究这些机制提供了很好的机会。在简要总结了目前关于植物中端粒特异性蛋白的知识状况之后，我们回顾了 DDR 过程以及与植物端粒稳定性相关的蛋白。我们特别关注端粒信号和无保护端粒诱导的重组事件，这些事件是基因组重排和不稳定的起源，当端粒功能受到影响时。
