Institute of Pharmacology and Toxicology, Paracelsus Medical University, Strubergasse 18, 5020 Salzburg, Austria.
EB House Austria, Research Program for Molecular Therapy of Genodermatoses, Department of Dermatology and Allergology, University Hospital of the Paracelsus Medical University, 5020 Salzburg, Austria.
Int J Mol Sci. 2021 Mar 24;22(7):3296. doi: 10.3390/ijms22073296.
The transcriptional regulator peroxisome proliferator activated receptor gamma coactivator 1A (PGC-1α), encoded by , has been linked to neurodegenerative diseases. Recently discovered CNS-specific transcripts are initiated far upstream of the reference promoter, spliced to exon 2 of the reference gene, and are more abundant than reference gene transcripts in post-mortem human brain samples. The proteins translated from the CNS and reference transcripts differ only at their N-terminal regions. To dissect functional differences between CNS-specific isoforms and reference proteins, we used clustered regularly interspaced short palindromic repeats transcriptional activation (CRISPRa) for selective endogenous activation of the CNS or the reference promoters in SH-SY5Y cells. Expression and/or exon usage of the targets was ascertained by RNA sequencing. Compared to controls, more differentially expressed genes were observed after activation of the CNS than the reference gene promoter, while the magnitude of alternative exon usage was comparable between activation of the two promoters. Promoter-selective associations were observed with canonical signaling pathways, mitochondrial and nervous system functions and neurological diseases. The distinct N-terminal as well as the shared downstream regions of PGC-1α isoforms affect the exon usage of numerous genes. Furthermore, associations of risk genes of amyotrophic lateral sclerosis and Parkinson's disease were noted with differentially expressed genes resulting from the activation of the CNS and reference gene promoter, respectively. Thus, CNS-specific isoforms markedly amplify the biological functions of and CNS-specific isoforms and reference proteins have common, complementary and selective functions relevant for neurodegenerative diseases.
转录调节因子过氧化物酶体增殖物激活受体 γ 共激活因子 1A（PGC-1α），由 编码，与神经退行性疾病有关。最近发现的中枢神经系统特异性 转录本起始于参考启动子的上游很远的位置，拼接至参考基因的外显子 2，并在死后人类大脑样本中比参考基因转录本更为丰富。从 CNS 和参考转录本翻译的蛋白质仅在其 N 端区域不同。为了剖析 CNS 特异性异构体和参考蛋白之间的功能差异，我们使用规律成簇间隔短回文重复转录激活（CRISPRa）在 SH-SY5Y 细胞中选择性地激活 CNS 或参考启动子。通过 RNA 测序确定靶基因的表达和/或外显子使用情况。与对照相比，在激活 CNS 启动子后观察到更多差异表达的基因，而两种启动子激活后，替代外显子使用的幅度相当。启动子选择性关联与经典信号通路、线粒体和神经系统功能以及神经退行性疾病有关。PGC-1α 异构体独特的 N 端以及共享的下游区域影响许多基因的外显子使用。此外，肌萎缩侧索硬化症和帕金森病风险基因的关联与 CNS 和参考基因启动子激活分别导致的差异表达基因有关。因此，CNS 特异性异构体显著放大了 的生物学功能，CNS 特异性异构体和参考蛋白具有共同的、互补的和选择性的功能，与神经退行性疾病相关。
