RT Journal Article SR Electronic T1 Biallelic ADPRHL2 mutations in complex neuropathy affect ADP ribosylation and DNA damage response JF Life Science Alliance JO Life Sci. Alliance FD Life Science Alliance LLC SP e202101057 DO 10.26508/lsa.202101057 VO 4 IS 11 A1 Danique Beijer A1 Thomas Agnew A1 Johannes Gregor Matthias Rack A1 Evgeniia Prokhorova A1 Tine Deconinck A1 Berten Ceulemans A1 Stojan Peric A1 Vedrana Milic Rasic A1 Peter De Jonghe A1 Ivan Ahel A1 Jonathan Baets YR 2021 UL https://www.life-science-alliance.org/content/4/11/e202101057.abstract AB ADP ribosylation is a reversible posttranslational modification mediated by poly(ADP-ribose)transferases (e.g., PARP1) and (ADP-ribosyl)hydrolases (e.g., ARH3 and PARG), ensuring synthesis and removal of mono-ADP-ribose or poly-ADP-ribose chains on protein substrates. Dysregulation of ADP ribosylation signaling has been associated with several neurodegenerative diseases, including Parkinson’s disease, amyotrophic lateral sclerosis, and Huntington’s disease. Recessive ADPRHL2/ARH3 mutations are described to cause a stress-induced epileptic ataxia syndrome with developmental delay and axonal neuropathy (CONDSIAS). Here, we present two families with a neuropathy predominant disorder and homozygous mutations in ADPRHL2. We characterized a novel C26F mutation, demonstrating protein instability and reduced protein function. Characterization of the recurrent V335G mutant demonstrated mild loss of expression with retained enzymatic activity. Although the V335G mutation retains its mitochondrial localization, it has altered cytosolic/nuclear localization. This minimally affects basal ADP ribosylation but results in elevated nuclear ADP ribosylation during stress, demonstrating the vital role of ADP ribosylation reversal by ARH3 in DNA damage control.