Department of Functional Genomics and Proteomics, Faculty of Science, Central European Institute of Technology, Masaryk University, Brno, Czech Republic.
Curr Protein Pept Sci. 2011 Mar;12(2):105-11. doi: 10.2174/138920311795684922.
Chromosome stability is conditioned by functional chromatin structure of chromosome ends - telomeres. Organisation and regulation of telomere maintenance represent a complex process whose details still remain enigmatic, especially in plants. Several telomere-binding or telomere-associated proteins and distinct epigenetic marks have been shown to influence telomere length and telomerase activity. HMGB proteins play important role in dynamic changes of chromatin structure and are involved in regulation of cellular processes of key importance, such as replication, transcription, recombination and DNA-repair. HMGB proteins in plants are more diversified than in other eukaryotes. Here, we summarise the roles of plant HMGB proteins in regulation of chromatin structure and dynamics and report on the newly identified role of AtHMGB1 protein in the regulation of plant telomere length. Astonishingly, contrary to mice mHMGB1 homologue, AtHMGB1 does not affect telomerase activity and AtHMGB1 loss or overexpression does not cause any obvious changes in chromatin architecture.
染色体稳定性取决于染色体末端——端粒的功能染色质结构。端粒维持的组织和调节是一个复杂的过程，其细节在植物中仍然很神秘。已经表明，几种端粒结合或与端粒相关的蛋白质和独特的表观遗传标记会影响端粒长度和端粒酶活性。HMGB 蛋白在染色质结构的动态变化中发挥重要作用，并参与调节细胞的关键过程，如复制、转录、重组和 DNA 修复。植物中的 HMGB 蛋白比其他真核生物更加多样化。在这里，我们总结了植物 HMGB 蛋白在调节染色质结构和动态方面的作用，并报告了 AtHMGB1 蛋白在调节植物端粒长度方面的新发现的作用。令人惊讶的是，与小鼠 mHMGB1 同源物相反，AtHMGB1 不影响端粒酶活性，AtHMGB1 的缺失或过表达不会导致染色质结构的任何明显变化。
