@article{32439510ef1040b7baa5e90a3fd0e92e,
title = "Flexible Tethering of ASPP Proteins Facilitates PP-1c Catalysis",
abstract = "ASPP (apoptosis-stimulating proteins of p53) proteins bind PP-1c (protein phosphatase 1) and regulate p53 impacting cancer cell growth and apoptosis. Here we determine the crystal structure of the oncogenic ASPP protein, iASPP, bound to PP-1c. The structure reveals a 1:1 complex that relies on interactions of the iASPP SILK and RVxF motifs with PP-1c, plus interactions of the PP-1c PxxPxR motif with the iASPP SH3 domain. Small-angle X-ray scattering analyses suggest that the crystal structure undergoes slow interconversion with more extended conformations in solution. We show that iASPP, and the tumor suppressor ASPP2, enhance the catalytic activity of PP-1c against the small-molecule substrate, pNPP as well as p53. The combined results suggest that PxxPxR binding to iASPP SH3 domain is critical for complex formation, and that the modular ASPP-PP-1c interface provides dynamic flexibility that enables functional binding and dephosphorylation of p53 and other diverse protein substrates.",
keywords = "ANK repeats, ASPP2, PP-1c, RVxF motif, SH3, Small angle X-ray scattering, X-ray crystallography, dephosphorylation, iASPP, p53",
author = "Yeyun Zhou and Robyn Millott and Kim, {Hyeong Jin} and Shiyun Peng and Edwards, {Ross A.} and Tamara Skene-Arnold and Michal Hammel and Lees-Miller, {Susan P.} and Tainer, {John A.} and Holmes, {Charles F.B.} and Glover, {J. N.Mark}",
note = "Funding Information: We thank Scott Classen and the staff at the Advanced Light Source beamline 12.3.1 for assistance with synchrotron data collection. This work was funded by grants from the Canadian Cancer Society Research Institute to J.N.M.G. and C.F.B.H. (no. 703775 ), NIH to J.N.M.G., M.H., and J.A.T. ( PO1CA092584 ), and Natural Sciences and Engineering Council of Canada to J.N.M.G. ( 2016-05163 ). J.A.T. is also supported by NIH R35 CA22043 , a Robert A. Welch Chemistry Chair, and the Cancer Prevention and Research Institute of Texas . This research used resources of the ALS SIBYLS facilities, which are a DOE Office of Science User Facility supported under the Integrated Diffraction Analysis Technologies (IDAT) program. Funding Information: We thank Scott Classen and the staff at the Advanced Light Source beamline 12.3.1 for assistance with synchrotron data collection. This work was funded by grants from the Canadian Cancer Society Research Institute to J.N.M.G. and C.F.B.H. (no. 703775), NIH to J.N.M.G. M.H. and J.A.T. (PO1CA092584), and Natural Sciences and Engineering Council of Canada to J.N.M.G. (2016-05163). J.A.T. is also supported by NIH R35 CA22043, a Robert A. Welch Chemistry Chair, and the Cancer Prevention and Research Institute of Texas. This research used resources of the ALS SIBYLS facilities, which are a DOE Office of Science User Facility supported under the Integrated Diffraction Analysis Technologies (IDAT) program. C.F.B.H. and J.N.M.G. designed the research. Y.Z. R.A.E. J.A.T. and J.N.M.G. performed crystallographic structure analysis. R.M. and T.S.-A. performed phosphatase assays. S.P.L.-M. purified DNA-PKcs. H.J.K. S.P. R.A.E. M.H. J.A.T. and J.N.M.G. performed and analyzed SEC-SAXS. H.J.K. performed EMSA. All authors contributed to writing of the paper. The authors declare no competing financial interests. Publisher Copyright: {\textcopyright} 2019 Elsevier Ltd",
year = "2019",
month = oct,
day = "1",
doi = "10.1016/j.str.2019.07.012",
language = "English (US)",
volume = "27",
pages = "1485--1496.e4",
journal = "Structure",
issn = "0969-2126",
publisher = "Cell Press",
number = "10",
}