Počet záznamů: 1  

Structural analysis of phosphatidylinositol 4-kinase III beta (PI4KB) - 14-3-3 protein complex reveals internal flexibility and explains 14-3-3 mediated protection from degradation in vitro

  1. 1.
    0481821 - ÚOCHB 2018 RIV US eng J - Článek v odborném periodiku
    Chalupská, Dominika - Eisenreichová, Andrea - Rozycki, B. - Řežábková, L. - Humpolíčková, Jana - Klíma, Martin - Bouřa, Evžen
    Structural analysis of phosphatidylinositol 4-kinase III beta (PI4KB) - 14-3-3 protein complex reveals internal flexibility and explains 14-3-3 mediated protection from degradation in vitro.
    Journal of Structural Biology. Roč. 200, č. 1 (2017), s. 36-44. ISSN 1047-8477. E-ISSN 1095-8657
    Grant CEP: GA ČR(CZ) GA17-05200S
    Institucionální podpora: RVO:61388963
    Klíčová slova: lipid * kinase * PI4KB * 14-3-3 protein * phosphatidylinositol
    Obor OECD: Biochemistry and molecular biology
    Impakt faktor: 3.433, rok: 2017

    Phosphatidylinositol 4-kinase III beta (PI4KB) is responsible for the synthesis of the Golgi and trans-Golgi network (TGN) pool of phosphatidylinositol 4-phospahte (PI4P). PI4P is the defining lipid hallmark of Golgi and TGN and also serves as a signaling lipid and as a precursor for higher phosphoinositides. In addition, PI4KB is hijacked by many single stranded plus RNA (+RNA) viruses to generate PI4P-rich membranes that serve as viral replication organelles. Given the importance of this enzyme in cells, it has to be regulated. 14-3-3 proteins bind PI4KB upon its phosphorylation by protein kinase D, however, the structural basis of PI4KB recognition by 14-3-3 proteins is unknown. Here, we characterized the PI4KB:14-3-3 protein complex biophysically and structurally. We discovered that the PI4KB:14-3-3 protein complex is tight and is formed with 2:2 stoichiometry. Surprisingly, the enzymatic activity of PI4KB is not directly modulated by 14-3-3 proteins. However, 14-3-3 proteins protect PI4KB from proteolytic degradation in vitro. Our structural analysis revealed that the PI4KB:14-3-3 protein complex is flexible but mostly within the disordered regions connecting the 14-3-3 binding site of the PI4KB with the rest of the PI4KB enzyme. It also predicted no direct modulation of PI4KB enzymatic activity by 14-3-3 proteins and that 14-3-3 binding will not interfere with PI4KB recruitment to the membrane by the ACBD3 protein. In addition, the structural analysis explains the observed protection from degradation, it revealed that several disordered regions of PI4KB become protected from proteolytical degradation upon 14-3-3 binding. All the structural predictions were subsequently biochemically validated.
    Trvalý link: http://hdl.handle.net/11104/0277472

     
     
Počet záznamů: 1  

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