Preprints (www.preprints.org) | NOT PEER-REVIEWED | Posted: 2 November 2018 doi:10.20944/preprints201811.0037.v1 Peer-reviewed version available at Biomolecules 2018, 8, 161; doi:10.3390/biom8040161 1 Review 2 Structural and Functional Insights into Human 3 Nuclear Cyclophilins 4 Caroline Rajiv12 and Tara L. Davis13,* 5 1 Department of Biochemistry and Molecular Biology, Drexel University College of Medicine, 6 Philadelphia PA USA 19102. 7 2 Janssen Pharmaceuticals, Inc., 22-21062, 1400 McKean Rd, Spring House, PA 19477; 8
[email protected] 9 3 FORMA Therapeutics, 550 Arsenal St. Ste. 100, Boston, MA 02472;
[email protected] 10 11 * Correspondence:
[email protected]; Tel.: +01-857-209-2342 12 13 Abstract: The peptidyl-prolyl isomerases of the cyclophilin type are distributed throughout human 14 cells, including eight found solely in the nucleus. Nuclear cyclophilins are involved in complexes 15 that regulate chromatin modification, transcription, and pre-mRNA splicing. This review collects 16 what is known about the eight human nuclear cyclophilins: PPIH, PPIE, PPIL1, PPIL2, PPIL3, PPIG, 17 CWC27, and PPWD1. Each “spliceophilin” is evaluated in relation to the spliceosomal complex in 18 which it has been studied, and current work studying the biological roles of these cyclophilins in 19 the nucleus are discussed. The eight human splicing complexes available in the RCSB are analyzed 20 from the viewpoint of the human spliceophilins. Future directions in structural and cellular biology, 21 and the importance of developing spliceophilin-specific inhibitors, are considered. 22 23 Keywords: Peptidyl-prolyl isomerases; nuclear cyclophilins; spliceophilins; alternative splicing; 24 spliceosomes; NMR; x-ray crystallography 25 26 27 1.