PROSITE documentation PDOC52098Protein phosphatase 1 (PP1)-binding domain profile
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PURL: https://purl.expasy.org/prosite/documentation/PDOC52098
Mitotic exit comprises a complex series of events that includes sister chromatid segregation, mitotic spindle disassembly, nuclear-envelope re-assembly and chromosome decondensation. Exiting mitosis requires the specific engagement and activation of protein phosphatases, including ser/thr phosphatase protein phosphatase 1 (PP1). While PP1 exhibits broad specificity, it acts in a highly specific manner by forming stable complexes, known as holoenzymes, with a host of regulatory proteins that direct PP1 activity towards specific substrates and localize PP1 to specific regions of the cell. During mitotic exit, PP1, in particular PP1γ (PP1 isoforms include PP1α, PP1β, PP1γ and PP1γ2), is essential for histone dephosphorylation, nuclear-envelope reassembly and chromatin remodeling. Repo-Man (recruits PP1γ onto mitotic chromatin at anaphase, also known as cell division cycle associated 2, CDCA2), and Ki-67 are important chromatin-associated PP1 regulatory subunits. Repo-Man and Ki-67 target PP1γ to anaphase chromosomes through their PP1-binding domains. This is required during mitotic exit to reverse mitotic histone phosphorylation. Repo-Man and Ki-67 bind PP1 using an identical mechanism, interacting with a PP1 pocket that is engaged only by these two PP1 regulators. These proteins exhibit sequence similarity in only a very short region, of about 40 residues. This region includes the canonical RVxF small linear motif (SLiM) that is critical for PP1 binding. The Ki-67 and Repo-Man PP1-binding domains form a classical β-hairpin on the top of PP1 that extends from the PP1 RVxF binding pocket towards the PP1 N-terminus and then back again (see <PDB:5J28>) [1,2,3,4].
The profile we developed covers the entire PP1-binding domain.
Last update:April 2026 / First entry.
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PROSITE method (with tools and information) covered by this documentation:
| 1 | Authors | Trinkle-Mulcahy L. Andersen J. Lam Y.W. Moorhead G. Mann M. Lamond A.I. |
| Title | Repo-Man recruits PP1 gamma to chromatin and is essential for cell viability. | |
| Source | J. Cell. Biol. 172:679-692(2006). | |
| PubMed ID | 16492807 | |
| DOI | 10.1083/jcb.200508154 |
| 2 | Authors | Booth D.G. Takagi M. Sanchez-Pulido L. Petfalski E. Vargiu G. Samejima K. Imamoto N. Ponting C.P. Tollervey D. Earnshaw W.C. Vagnarelli P. |
| Title | Ki-67 is a PP1-interacting protein that organises the mitotic chromosome periphery. | |
| Source | Elife 3:E01641-E01641(2014). | |
| PubMed ID | 24867636 | |
| DOI | 10.7554/eLife.01641 |
| 3 | Authors | Kumar G.S. Gokhan E. De Munter S. Bollen M. Vagnarelli P. Peti W. Page R. |
| Title | The Ki-67 and RepoMan mitotic phosphatases assemble via an identical, yet novel mechanism. | |
| Source | Elife 5:0-0(2016). | |
| PubMed ID | 27572260 | |
| DOI | 10.7554/eLife.16539 |
| 4 | Authors | Remnant L. Kochanova N.Y. Reid C. Cisneros-Soberanis F. Earnshaw W.C. |
| Title | The intrinsically disorderly story of Ki-67. | |
| Source | Open. Biol. 11:210120-210120(2021). | |
| PubMed ID | 34375547 | |
| DOI | 10.1098/rsob.210120 |
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