State Key Laboratory of Tree Genetics and Breeding, National Engineering Research Center of Tree Breeding and Ecological Restoration, Beijing Forestry University, Beijing 100083, China; The Tree and Ornamental Plant Breeding and Biotechnology Laboratory of National Forestry and Grassland Administration, College of Biological Sciences and Technology, Beijing Forestry University, Beijing 100083, China.
State Key Laboratory of Tree Genetics and Breeding, National Engineering Research Center of Tree Breeding and Ecological Restoration, Beijing Forestry University, Beijing 100083, China; The Tree and Ornamental Plant Breeding and Biotechnology Laboratory of National Forestry and Grassland Administration, College of Biological Sciences and Technology, Beijing Forestry University, Beijing 100083, China; School of Biology and Engineering (School of Modern Industry for Health and Medicine), Guizhou Medical University, Guiyang 561113, China.
Int J Biol Macromol. 2024 Nov;279(Pt 4):135240. doi: 10.1016/j.ijbiomac.2024.135240. Epub 2024 Sep 7.
The heat shock protein 90 (HSP90) family members are not only widely involved in animal cellular immune response and signal transduction pathway regulation, but also play an important role in plant development and environmental stress response. Here,we identified a HSP90 family member in Ginkgo biloba, designated as GbHSP90, which performs a dual functional role to regulate telomere stability. GbHSP90 was screened by a yeast one-hybrid library using the Ginkgo biloba telomeric DNA (TTTAGGG). Fluorescence polarization, surface plasmon resonance(SPR) and EMSA technologyies revealed a specific interaction between GbHSP90 and the double-stranded telomeric DNA via its N-CR region, with no affinity for the single-stranded telomeric DNA or human double-stranded telomeric DNA. Furthermore, yeast two-hybrid system and Split-LUC assay demonstrated that GbHSP90 can interacts with two telomere end-binding proteins:the ginkgo telomerase reverse transcriptase (GbTERT) and the ginkgo Structural Maintenance of Chromosomes protein 1 (GbSMC1). Overexpression of GbHSP90 in human 293 T and HeLa cells increased cell growth rate, the content of telomerase reverse transcriptase (TERT), and promote cell division and inhibit cell apoptosis. Our results indicated GbHSP90 have dually functions: as a telomere-binding protein that binds specifically to double-stranded telomeric DNA and as a molecular chaperone that modulates cell differentiation and apoptosis by binding to telomere protein complexes in Ginkgo biloba. This study contributes to a significantly understanding of the unique telomere complex structure and regulatory mechanisms in Ginkgo biloba, a long-lived tree species.
热休克蛋白 90（HSP90）家族成员不仅广泛参与动物细胞免疫反应和信号转导途径的调节，而且在植物发育和环境胁迫反应中也发挥着重要作用。在这里，我们鉴定了银杏中的一个 HSP90 家族成员，命名为 GbHSP90，它具有调节端粒稳定性的双重功能。GbHSP90 是通过银杏端粒 DNA（TTTAGGG）的酵母单杂交文库筛选出来的。荧光偏振、表面等离子体共振（SPR）和 EMSA 技术表明，GbHSP90 通过其 N-CR 区域与双链端粒 DNA 特异性相互作用，而与单链端粒 DNA 或人双链端粒 DNA 没有亲和力。此外，酵母双杂交系统和 Split-LUC 测定表明，GbHSP90 可以与两个端粒末端结合蛋白相互作用：银杏端粒酶逆转录酶（GbTERT）和银杏结构维持染色体蛋白 1（GbSMC1）。在人 293T 和 HeLa 细胞中过表达 GbHSP90 会增加细胞生长速度、端粒酶逆转录酶（TERT）的含量，促进细胞分裂并抑制细胞凋亡。我们的结果表明，GbHSP90 具有双重功能：作为一种端粒结合蛋白，特异性结合双链端粒 DNA，以及作为一种分子伴侣，通过与银杏中端粒蛋白复合物结合来调节细胞分化和凋亡。这项研究有助于深入了解银杏这一长寿树种独特的端粒复合物结构和调控机制。
