TY - JOUR TI - The C9ORF72 GGGGCC expansion forms RNA G-quadruplex inclusions and sequesters hnRNP H to disrupt splicing in ALS brains AU - Conlon, Erin G AU - Lu, Lei AU - Sharma, Aarti AU - Yamazaki, Takashi AU - Tang, Timothy AU - Shneider, Neil A AU - Manley, James L A2 - Black, Douglas L VL - 5 PY - 2016 DA - 2016/09/13 SP - e17820 C1 - eLife 2016;5:e17820 DO - 10.7554/eLife.17820 UR - https://doi.org/10.7554/eLife.17820 AB - An expanded GGGGCC hexanucleotide in C9ORF72 (C9) is the most frequent known cause of amyotrophic lateral sclerosis (ALS) and frontotemporal dementia (FTD). It has been proposed that expanded transcripts adopt G-quadruplex (G-Q) structures and associate with proteins, but whether this occurs and contributes to disease is unknown. Here we show first that the protein that predominantly associates with GGGGCC repeat RNA in vitro is the splicing factor hnRNP H, and that this interaction is linked to G-Q formation. We then show that G-Q RNA foci are more abundant in C9 ALS patient fibroblasts and astrocytes compared to those without the expansion, and more frequently colocalize with hnRNP H. Importantly, we demonstrate dysregulated splicing of multiple known hnRNP H-target transcripts in C9 patient brains, which correlates with elevated insoluble hnRNP H/G-Q aggregates. Together, our data implicate C9 expansion-mediated sequestration of hnRNP H as a significant contributor to neurodegeneration in C9 ALS/FTD. KW - amyotrophic lateral sclerosis KW - RNA structure KW - disease mechanism JF - eLife SN - 2050-084X PB - eLife Sciences Publications, Ltd ER -