Putative RNA exonuclease which protects neurons from the toxic effects of expanded poly-Q disease proteins (PubMed:12486229). It is unknown whether this is via participation in the pathogenic mechanism underlying poly-Q-induced neurodegeneration or if it is by acting as a genetic modifier of the age of onset or progression of neurodegeneration (PubMed:12486229). Regulates gene expression in neurons (PubMed:22870397). Forms aggregates in the nucleus. Expressed in the excretory canal, vulval cells, the intestine and in head and tail neurons including ASH, RIC and AIZ neurons. The Gln/Pro-rich N-terminus and the Arg/Asp/Glu/Lys-rich charged domain are critical in protecting glutamatergic ASH sensory neurons from degeneration. ASH neurons expressing isoforms lacking these domains show progressive degeneration. Belongs to the REXO1/REXO3 family.