Involved in repair of DNA damage following UV irradiation, acting either in the absence of ERCC6 or synergistically with ERCC6. Involved in the regulation of gene expression. In the absence of ERCC6, induces the expression of genes characteristic of interferon-like antiviral responses. This response is almost completely suppressed in the presence of ERCC6. In the presence of ERCC6, regulates the expression of genes involved in metabolism regulation, including IGFBP5 and IGFBP7. In vitro binds to PGBD3-related transposable elements, called MER85s; these non-autonomous 140 bp elements are characterized by the presence of PGBD3 terminal inverted repeats and the absence of internal transposase ORF. Expressed in heart and oocytes, but not in granulosa cells (at protein level). The protein represented in this entry is involved in disease pathogenesis. Disease-causing variants affect isoform CSB-PGBD3, which is a chimeric protein between ERCC6 N-terminus and the entire PGBD3 sequence. Produced by an alternative splicing event that joins the first 5 exons of ERCC6 gene in frame to the entire PGBD3 coding region, which is located within ERCC6 intron 5. The resulting chimeric protein consists of the N-terminal 465 residues of ERCC6 tethered to the entire PGBD3 sequence.