4WAA

Crystal structure of Nix LIR-fused human LC3B_2-119

Summary for 4WAA

• Entry DOI: 10.2210/pdb4waa/pdb
• Descriptor: Microtubule-associated proteins 1A/1B light chain 3B (2 entities in total)
• Functional Keywords: autophagy, selective autophagy, degradation, nix, lc3, recycling, lir, structural protein
• Biological source: Homo sapiens (Human)
• Total number of polymer chains: 2
• Total formula weight: 31171.52

Authors

Suzuki, H.,Ravichandran, A.C.,Dobson, R.C.J.,Novak, I.,Wakatsuki, S. (deposition date: 2014-08-29, release date: 2015-09-09, Last modification date: 2024-01-10)

Primary citation

Rogov, V.V.,Suzuki, H.,Marinkovic, M.,Lang, V.,Kato, R.,Kawasaki, M.,Buljubasic, M.,Sprung, M.,Rogova, N.,Wakatsuki, S.,Hamacher-Brady, A.,Dotsch, V.,Dikic, I.,Brady, N.R.,Novak, I.
Phosphorylation of the mitochondrial autophagy receptor Nix enhances its interaction with LC3 proteins.
Sci Rep, 7:1131-1131, 2017

PubMed 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.

PubMed: 28442745
DOI: 10.1038/s41598-017-01258-6

Experimental method

X-RAY DIFFRACTION (2.35 Å)