Inhibits translesion DNA synthesis by preventing monoubiquitination of PCNA, this is necessary to counteract damage due to ultraviolet light-induced replication stress (By similarity). SDE2 is cleaved following PCNA binding, and its complete degradation is necessary to allow S-phase progression following DNA damage (By similarity).
Plays a role in pre-mRNA splicing by facilitating excision of relatively short introns featuring weak 3'-splice sites (ss) and high GC content (By similarity). May recruit CACTIN to the spliceosome (By similarity).
Plays a role in ribosome biogenesis by enabling SNORD3- and SNORD118-dependent cleavage of the 47S rRNA precursor (By similarity). Binds ncRNA (non-coding RNA) including the snoRNAs SNORD3 and SNORD118 (By similarity).
Subcellular locations: Nucleus, Cytoplasm