| Structural highlights
Function
[PP1G_HUMAN] Protein phosphatase that associates with over 200 regulatory proteins to form highly specific holoenzymes which dephosphorylate hundreds of biological targets. Protein phosphatase 1 (PP1) is essential for cell division, and participates in the regulation of glycogen metabolism, muscle contractility and protein synthesis. Dephosphorylates RPS6KB1. Involved in regulation of ionic conductances and long-term synaptic plasticity. May play an important role in dephosphorylating substrates such as the postsynaptic density-associated Ca(2+)/calmodulin dependent protein kinase II. Component of the PTW/PP1 phosphatase complex, which plays a role in the control of chromatin structure and cell cycle progression during the transition from mitosis into interphase.[1] [2] [CDCA2_HUMAN] Regulator of chromosome structure during mitosis required for condensin-depleted chromosomes to retain their compact architecture through anaphase. Acts by mediating the recruitment of phopsphatase PP1-gamma subunit (PPP1CC) to chromatin at anaphase and into the following interphase. At anaphase onset, its association with chromatin targets a pool of PPP1CC to dephosphorylate substrates.[3] [4]
Publication Abstract from PubMed
Ki-67 and RepoMan have key roles during mitotic exit. Previously, we showed that Ki-67 organizes the mitotic chromosome periphery and recruits protein phosphatase 1 (PP1) to chromatin at anaphase onset, in a similar manner as RepoMan (Booth et al., 2014). Here we show how Ki-67 and RepoMan form mitotic exit phosphatases by recruiting PP1, how they distinguish between distinct PP1 isoforms and how the assembly of these two holoenzymes are dynamically regulated by Aurora B kinase during mitosis. Unexpectedly, our data also reveal that Ki-67 and RepoMan bind PP1 using an identical, yet novel mechanism, interacting with a PP1 pocket that is engaged only by these two PP1 regulators. These findings not only show how two distinct mitotic exit phosphatases are recruited to their substrates, but also provide immediate opportunities for the design of novel cancer therapeutics that selectively target the Ki-67:PP1 and RepoMan:PP1 holoenzymes.
The Ki-67 and RepoMan mitotic phosphatases assemble via an identical, yet novel mechanism.,Kumar GS, Gokhan E, De Munter S, Bollen M, Vagnarelli P, Peti W, Page R Elife. 2016 Aug 30;5. pii: e16539. doi: 10.7554/eLife.16539. PMID:27572260[5]
From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine.
See Also
References
- ↑ Djouder N, Metzler SC, Schmidt A, Wirbelauer C, Gstaiger M, Aebersold R, Hess D, Krek W. S6K1-mediated disassembly of mitochondrial URI/PP1gamma complexes activates a negative feedback program that counters S6K1 survival signaling. Mol Cell. 2007 Oct 12;28(1):28-40. PMID:17936702 doi:http://dx.doi.org/10.1016/j.molcel.2007.08.010
- ↑ Lee JH, You J, Dobrota E, Skalnik DG. Identification and characterization of a novel human PP1 phosphatase complex. J Biol Chem. 2010 Aug 6;285(32):24466-76. doi: 10.1074/jbc.M110.109801. Epub 2010, Jun 1. PMID:20516061 doi:http://dx.doi.org/10.1074/jbc.M110.109801
- ↑ Trinkle-Mulcahy L, Andersen J, Lam YW, Moorhead G, Mann M, Lamond AI. Repo-Man recruits PP1 gamma to chromatin and is essential for cell viability. J Cell Biol. 2006 Feb 27;172(5):679-92. Epub 2006 Feb 21. PMID:16492807 doi:http://dx.doi.org/10.1083/jcb.200508154
- ↑ Vagnarelli P, Hudson DF, Ribeiro SA, Trinkle-Mulcahy L, Spence JM, Lai F, Farr CJ, Lamond AI, Earnshaw WC. Condensin and Repo-Man-PP1 co-operate in the regulation of chromosome architecture during mitosis. Nat Cell Biol. 2006 Oct;8(10):1133-42. Epub 2006 Sep 24. PMID:16998479 doi:http://dx.doi.org/ncb1475
- ↑ Kumar GS, Gokhan E, De Munter S, Bollen M, Vagnarelli P, Peti W, Page R. The Ki-67 and RepoMan mitotic phosphatases assemble via an identical, yet novel mechanism. Elife. 2016 Aug 30;5. pii: e16539. doi: 10.7554/eLife.16539. PMID:27572260 doi:http://dx.doi.org/10.7554/eLife.16539
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