PPIases accelerate the folding of proteins. It catalyzes the cis-trans isomerization of proline imidic peptide bonds in oligopeptides. Influences somehow regulation of RNA pol II (CTD) phosphorylation. Binds RNA with preferences for GC-rich sequences. Probably involved in activities connecting transcription and pre-mRNA processing. Involved in brassinostroid response. [protein]-peptidylproline (omega=180) = [protein]-peptidylproline (omega=0) Component of the BZR1 complex. Interacts with NRPB1 (via CTD domain), SCL28, SCL30, SCL30A, SCL33, SC35, SR30, SR34, RSZ21, RS2Z33, RS31 and RS40. Shows a punctuate localization pattern distinct from the nuclear speckles. Ubiquitous. Belongs to the cyclophilin-type PPIase family.