14-3-3 protein masks the nuclear localization sequence of caspase-2

0498388 - FGÚ 2019 RIV GB eng J - Článek v odborném periodiku
Šmídová, Aneta - Alblová, Miroslava - Kalábová, Dana - Pšenáková, Katarína - Rosůlek, Michal - Herman, P. - Obšil, Tomáš - Obšilová, Veronika
14-3-3 protein masks the nuclear localization sequence of caspase-2.
FEBS Journal. Roč. 285, č. 22 (2018), s. 4196-4213. ISSN 1742-464X. E-ISSN 1742-4658
Grant CEP: GA ČR(CZ) GA17-00726S; GA MŠMT(CZ) ED1.1.00/02.0109
Institucionální podpora: RVO:67985823 ; RVO:61388971
Klíčová slova: 14‐3‐3 protein * caspase‐2 * fluorescence * nuclear localization sequence * protein–protein interactions * small angle X‐ray scattering
Obor OECD: Biochemistry and molecular biology
Impakt faktor: 4.739, rok: 2018

Caspase-2 is an apical protease responsible for the proteolysis of cellular substrates directly involved in mediating apoptotic signaling cascades. Caspase-2 activation is inhibited by phosphorylation followed by binding to the scaffolding protein 14-3-3, which recognizes two phosphoserines located in the linker between the caspase recruitment domain and the p19 domains of the caspase-2 zymogen. However, the structural details of this interaction and the exact role of 14-3-3 in the regulation of caspase-2 activation remain unclear. Moreover, the caspase-2 region with both 14-3-3-binding motifs also contains the nuclear localization sequence (NLS), thus suggesting that 14-3-3 binding may regulate the subcellular localization of caspase-2. Here, we report a structural analysis of the 14-3-3 zeta:caspase-2 complex using a combined approach based on small angle X-ray scattering, NMR, chemical cross-linking, and fluorescence spectroscopy. The structural model proposed in this study suggests that phosphorylated caspase-2 and 14-3-3 zeta form a compact and rigid complex in which the p19 and the p12 domains of caspase-2 are positioned within the central channel of the 14-3-3 dimer and stabilized through interactions with the C-terminal helices of both 14-3-3 zeta protomers. In this conformation, the surface of the p12 domain, which is involved in caspase-2 activation by dimerization, is sterically occluded by the 14-3-3 dimer, thereby likely preventing caspase-2 activation. In addition, 14-3-3 protein binding to caspase-2 masks its NLS. Therefore, our results suggest that 14-3-3 protein binding to caspase-2 may play a key role in regulating caspase-2 activation.
Trvalý link: http://hdl.handle.net/11104/0290764