title: Structural probing of a protein phosphatase 2A network by chemical cross-linking and mass spectrometry.
abstract: The identification of proximate amino acids by chemical cross-linking and mass spectrometry (XL-MS) facilitates the structural analysis of homogeneous protein complexes. We gained distance restraints on a modular interaction network of protein complexes affinity-purified from human cells by applying an adapted XL-MS protocol. Systematic analysis of human protein phosphatase 2A (PP2A) complexes identified 176 interprotein and 570 intraprotein cross-links that link specific trimeric PP2A complexes to a multitude of adaptor proteins that control their cellular functions. Spatial restraints guided molecular modeling of the binding interface between immunoglobulin binding protein 1 (IGBP1) and PP2A and revealed the topology of TCP1 ring complex (TRiC) chaperonin interacting with the PP2A regulatory subunit 2ABG. This study establishes XL-MS as an integral part of hybrid structural biology approaches for the analysis of endogenous protein complexes.
authors.affiliation: Department of Biology, Institute of Molecular Systems Biology, Eidgenössische Technische Hochschule Zürich, Wolfgang-Pauli Strasse 16, 8093 Zurich, Switzerland.
authors.forename: Franz
authors.initials: F
authors.lastname: Herzog
authors.forename: Abdullah
authors.initials: A
authors.lastname: Kahraman
authors.forename: Daniel
authors.initials: D
authors.lastname: Boehringer
authors.forename: Raymond
authors.initials: R
authors.lastname: Mak
authors.forename: Andreas
authors.initials: A
authors.lastname: Bracher
authors.forename: Thomas
authors.initials: T
authors.lastname: Walzthoeni
authors.forename: Alexander
authors.initials: A
authors.lastname: Leitner
authors.forename: Martin
authors.initials: M
authors.lastname: Beck
authors.forename: Franz-Ulrich
authors.initials: FU
authors.lastname: Hartl
authors.forename: Nenad
authors.initials: N
authors.lastname: Ban
authors.forename: Lars
authors.initials: L
authors.lastname: Malmström
authors.forename: Ruedi
authors.initials: R
authors.lastname: Aebersold
mesh_terms: D018833:Chaperonins / Q000737:chemistry; D003432:Cross-Linking Reagents / Q000737:chemistry; D018360:Crystallography, X-Ray; D006801:Humans; D013058:Mass Spectrometry / Q000379:methods*; D053858:Metabolic Networks and Pathways; D011487:Protein Conformation; D025941:Protein Interaction Mapping / Q000379:methods*; D054648:Protein Phosphatase 2 / Q000737:chemistry*
chemical_list: D003432:Cross-Linking Reagents; D054648:Protein Phosphatase 2; D018833:Chaperonins