The function of Ensembl gene identifier ENSG00000138231 (DBR1, debranching RNA lariats 1) is as follows. Cleaves the 2'-5' phosphodiester linkage at the branch point of excised lariat intron RNA and converts them into linear molecules that can be subsequently degraded, thereby facilitating ribonucleotide turnover (PubMed:10982890, PubMed:16232320, PubMed:2435736). Linked to its role in pre-mRNA processing mechanism, may also participate in retrovirus replication via an RNA lariat intermediate in cDNA synthesis and have an antiviral cell-intrinsic defense function in the brainstem (PubMed:16232320, PubMed:29474921). {ECO:0000269|PubMed:10982890, ECO:0000269|PubMed:16232320, ECO:0000269|PubMed:2435736, ECO:0000269|PubMed:29474921}.