2KNV

NMR dimer structure of the UBA domain of p62 (SQSTM1)

2KNV の概要

• エントリーDOI: 10.2210/pdb2knv/pdb
• 関連するPDBエントリー: 2JY7 2K0B
• 分子名称: Sequestosome-1 (1 entity in total)
• 機能のキーワード: ubiquitin binding, ubiquitin-associated domain, paget s disease of bone, helical bundle, dimer, protein binding
• 由来する生物種: Homo sapiens (human)
• 細胞内の位置: Cytoplasm: Q13501
• タンパク質・核酸の鎖数: 2
• 化学式量合計: 11488.81

構造登録者

Long, J.E.,Searle, M.S. (登録日: 2009-09-04, 公開日: 2009-12-15, 最終更新日: 2024-05-29)

主引用文献

Long, J.,Garner, T.P.,Pandya, M.J.,Craven, C.J.,Chen, P.,Shaw, B.,Williamson, M.P.,Layfield, R.,Searle, M.S.
Dimerisation of the UBA Domain of p62 Inhibits Ubiquitin Binding and Regulates NF-kappaB Signalling
J.Mol.Biol., 2009

PubMed Abstract: The ubiquitin (Ub)-binding p62 scaffold protein (encoded by the SQSTM1 gene) regulates a diverse range of signalling pathways leading to activation of the nuclear factor kappa B (NF-kappaB) family of transcription factors and is an important regulator of macroautophagy. Mutations within the gene encoding p62 are commonly found in patients with Paget's disease of bone and largely cluster within the C-terminal ubiquitin-associated (UBA) domain, impairing its ability to bind Ub, resulting in dysregulated NF-kappaB signalling. However, precisely how Ub-binding is regulated at the molecular level is unclear. NMR relaxation dispersion experiments, coupled with concentration-dependent NMR, CD, isothermal titration calorimetry and fluorescence kinetic measurements, reveal that the p62 UBA domain forms a highly stable dimer (K(dim) approximately 4-12 microM at 298 K). NMR analysis shows that the dimer interface partially occludes the Ub-binding surface, particularly at the C-terminus of helix 3, making UBA dimerisation and Ub-binding mutually exclusive processes. Somewhat unusually, the monomeric UBA appears to be the biologically active form and the dimer appears to be the inactive one. Engineered point mutations in loop 1 (E409K and G410K) are shown to destabilise the dimer interface, lead to a higher proportion of the bound monomer and, in NF-kappaB luciferase reporter assays, are associated with reduced NF-kappaB activity compared with wt-p62.

PubMed: 19931284
DOI: 10.1016/j.jmb.2009.11.032

実験手法

SOLUTION NMR