catalytic activity:Peptidylproline (omega=180) = peptidylproline (omega=0).,domain:The RS domain is required for the interaction with the phosphorylated C-terminal domain of RNA polymerase II.,enzyme regulation:Cyclosporin A (CsA)-sensitive.,function:PPIases accelerate the folding of proteins.,function:PPIases accelerate the folding of proteins. It catalyzes the cis-trans isomerization of proline imidic peptide bonds in oligopeptides.,function:PPIases accelerate the folding of proteins. It catalyzes the cis-trans isomerization of proline imidic peptide bonds in oligopeptides. May be implicated in the folding, transport, and assembly of proteins. May play an important role in the regulation of pre-mRNA splicing.,PTM:Phosphorylated upon DNA damage, probably by ATM or ATR.,similarity:Belongs to the cyclophilin-type PPIase family.,similarity:Contains 1 PPIase cyclophilin-type domain.,subcellular location:Colocalizes with RNA splicing factors at nuclear speckles.,subunit:Interacts with CLK1, PNN and with the phosphorylated C-terminal domain of RNA polymerase II.,tissue specificity:Ubiquitous.,