XRCC1 mutation is associated with PARP1 hyperactivation and cerebellar ataxia.

XRCC1 is a molecular scaffold protein that assembles multi-protein complexes involved in DNA single-strand break repair. Here we show that biallelic mutations in the human XRCC1 gene are associated with ocular motor apraxia, axonal neuropathy, and progressive cerebellar ataxia. Cells from a patient with mutations in XRCC1 exhibited not only reduced rates of single-strand break repair but also elevated levels of protein ADP-ribosylation. This latter phenotype is recapitulated in a related syndrome caused by mutations in the XRCC1 partner protein PNKP and implicates hyperactivation of poly(ADP-ribose) polymerase/s as a cause of cerebellar ataxia. Indeed, remarkably, genetic deletion of Parp1 rescued normal cerebellar ADP-ribose levels and reduced the loss of cerebellar neurons and ataxia in Xrcc1-defective mice, identifying a molecular mechanism by which endogenous single-strand breaks trigger neuropathology. Collectively, these data establish the importance of XRCC1 protein complexes for normal neurological function and identify PARP1 as a therapeutic target in DNA strand break repair-defective disease.

Citation

Nicolas C Hoch, Hana Hanzlikova, Stuart L Rulten, Martine Tétreault, Emilia Komulainen, Limei Ju, Peter Hornyak, Zhihong Zeng, William Gittens, Stephanie A Rey, Kevin Staras, Grazia M S Mancini, Peter J McKinnon, Zhao-Qi Wang, Justin D Wagner, Care4Rare Canada Consortium, Grace Yoon, Keith W Caldecott. XRCC1 mutation is associated with PARP1 hyperactivation and cerebellar ataxia. Nature. 2017 Jan 05;541(7635):87-91

Mesh Tags

Substances

PMID: 28002403

search → result