Nobuo N. NODA

Autophagy regulation by liquid-liquid
phase separation

Laboratory of Structural Biology
Institute of Microbial Chemistry, Japan
Contact : nn [at sign] bikaken.or.jp

Nobuo N. NODA

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Laboratory of Structural Biology, Institute of Microbial Chemistry, Japan

Autophagy is an intracellular degradation system that involves de novo generation of autophagosomes, which sequester

Research Interests

cytoplasmic materials and deliver them to the lysosome/vacuole for degradation. When autophagy is induced by starvation,

Autophagy, Phase Separation, Structural Biology, In Vitro Reconstitution

generating bulk autophagosomes that randomly sequester cytoplasmic materials. On the other hand, there exist selective types

autophagy-related (Atg) proteins gather to form the pre-autophagosomal structure (PAS), which functions as a place forof autophagy termed “selective autophagy”, during which autophagosome generation proceeds on the specific large cargo that
includes membrane-bound and membraneless organelles. Recently, we noticed that the PAS is a liquid droplet of Atg proteins

Education
2001

that is formed by liquid-liquid phase separation (LLPS) [1]. LLPS of the PAS is strictly regulated by the phosphorylation state ofPh. D., Graduate School of Pharmaceutical Sciences, The University of Tokyo

Atg13, an intrinsically disordered protein. Upon starvation, Atg13 is dephosphorylated, which links Atg17 dimers to each other toform a large assemblage [2]. In vitro mixing of Atg13 with Atg17 resulted in the formation of liquid droplets, and point mutationsin Atg13 or Atg17 that impaired the droplet formation in vitro also impaired the PAS formation in vivo, suggesting that the PAS isProfessional Career2001 - 2005
2005 - 2007
2007 - 2011
2011 - 20172017 - present

Postdoctoral Fellow, Hokkaido University

formed by the LLPS of the Atg13-Atg17 complex. High-speed atomic force microscopy observation of the Atg13-Atg17 droplets
revealed randomly arranged, mobile Atg17 molecules inside the droplets, supporting the liquid-like feature of the droplets [1].
Aminopeptidase I (Ape1) is known to be a specific cargo for selective autophagy. We noticed that Ape1 undergoes LLPS to form
Ape1 droplets both in vitro and in vivo [3]. Mutations that impair LLPS or solidify the Ape1 droplets impaired the selectiveResearch Associate, Hokkaido University

autophagy of Ape1, suggesting that the liquid-like feature of Ape1 droplets is important for selective autophagy. In vitro

Lecturer with Tenure, Hokkaido University

reconstitution experiments revealed that liquid-like Ape1 droplets formed by LLPS, but not Ape1 aggregates that lost theChief Researcher, Institute of Microbial Chemistry

liquidity by a mutation, were selectively sequestered by a membrane coated with Atg proteins. These data suggest that LLPS canbe a general mechanism for regulating both bulk and selective autophagy.

Laboratory Head, Institute of Microbial Chemistry

Scientific Activities
2002 - present
2016 - present

Structural biology of autophagy

References

In vitro reconstitution of autophagy and phase separation[ 1 ] Y. Fujioka, J. M. Alam, D. Noshiro, K. Mouri, T. Ando, Y. Okada, A. I. May, R. L. Knorr, K. Suzuki, Y. Ohsumi, N. N. Noda,“Phase separation organizes the site of autophagosome formation”, Nature, 578 (2020) 301-305.

Honors2012[ 2 ] H. Yamamoto, Y. Fujioka, S. W. Suzuki, D. Noshiro, H. Suzuki, C. Kondo-Kakuta, Y. Kimura, H. Hirano, T. Ando, N.
Young Investigator Award, The Japanese Biochemical Society

N. Noda, Y. Ohsumi, “The intrinsically disordered protein Atg13 mediates supramolecular assembly of autophagy
initiation complexes”, Dev. Cell, 38 (2016) 86-99.
[ 3 ] A. Yamasaki, J. M. Alam, D. Noshiro, E. Hirata, Y. Fujioka, K. Suzuki, Y. Ohsumi, N. N. Noda, “Liquidity is a critical

Publications

determinant for selective autophagy of protein condensates”, Mol. Cell, 77 (2020), 1163-1175.

Y. Fujioka, J. M. Alam, D. Noshiro, K. Mouri, T. Ando, Y. Okada, A. I. May, R. L. Knorr, K. Suzuki, Y. Ohsumi, N. N. Noda, “Phase separation organizes

1. the site of autophagosome formation”, Nature, 578 (2020) 301-305.

A. Yamasaki, J. M. Alam, D. Noshiro, E. Hirata, Y. Fujioka, K. Suzuki, Y. Ohsumi, N. N. Noda, “Liquidity is a critical determinant for selective autophagy of protein

2. condensates”, Mol. Cell, 77 (2020), 1163-1175.

T. Osawa, T. Kotani, T. Kawaoka, E. Hirata, K. Suzuki, H. Nakatogawa, Y. Ohsumi, N. N. Noda, “Atg2 mediates direct lipid transfer between mem-3. branes for autophagosome formation”, Nat. Struct. Mol. Biol., 26 (2019), 281-288.

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