Phosphorylation of the mitochondrial autophagy receptor Nix enhances its interaction with LC3 proteins

• Verfasst von: Rogov, Vladimir V. [VerfasserIn]
• Verfasst von: Lang, Verena [VerfasserIn]
• Verfasst von: Hamacher-Brady, Anne [VerfasserIn]
• Verfasst von: Brady, Nathan [VerfasserIn]
• Titel: Phosphorylation of the mitochondrial autophagy receptor Nix enhances its interaction with LC3 proteins
• Verf.angabe: Vladimir V. Rogov, Hironori Suzuki, Mija Marinković, Verena Lang, Ryuichi Kato, Masato Kawasaki, Maja Buljubašić, Matilda Šprung, Natalia Rogova, Soichi Wakatsuki, Anne Hamacher-Brady, Volker Dötsch, Ivan Dikic, Nathan R. Brady & Ivana Novak
• E-Jahr: 2017
• Jahr: 25 April 2018
• Fussnoten: Gesehen am 17.08.2018
• Titel Quelle: Enthalten in: Scientific reports
• Ort Quelle: [London] : Macmillan Publishers Limited, part of Springer Nature, 2011
• Jahr Quelle: 2017
• Band/Heft Quelle: 7(2017) Artikel-Nummer 1131, 12 Seiten
• ISSN Quelle: 2045-2322
• DOI: doi:10.1038/s41598-017-01258-6
• Datenträger: Online-Ressource
• Sprache: eng
• K10plus-PPN: 1580169961

Abstract

The mitophagy receptor Nix interacts with LC3/GABARAP proteins, targeting mitochondria into autophagosomes for degradation. Here we present evidence for phosphorylation-driven regulation of the Nix:LC3B interaction. Isothermal titration calorimetry and NMR indicate a ~100 fold enhanced affinity of the serine 34/35-phosphorylated Nix LC3-interacting region (LIR) to LC3B and formation of a very rigid complex compared to the non-phosphorylated sequence. Moreover, the crystal structure of LC3B in complex with the Nix LIR peptide containing glutamic acids as phosphomimetic residues and NMR experiments revealed that LIR phosphorylation stabilizes the Nix:LC3B complex via formation of two additional hydrogen bonds between phosphorylated serines of Nix LIR and Arg11, Lys49 and Lys51 in LC3B. Substitution of Lys51 to Ala in LC3B abrogates binding of a phosphomimetic Nix mutant. Functionally, serine 34/35 phosphorylation enhances autophagosome recruitment to mitochondria in HeLa cells. Together, this study provides cellular, biochemical and biophysical evidence that phosphorylation of the LIR domain of Nix enhances mitophagy receptor engagement.