Nobuo N. Noda

Autophagy is a bulk degradation system conserved among most eukaryotes. Recently, autophagy has been shown to mediate selective degradation of various targets such as aggregated proteins and damaged or superfluous organelles. Structural studies have uncovered the conserved specific interactions between autophagic receptors and Atg8-family proteins through WXXL-like sequences, which we term the Atg8-family interacting motif (AIM). AIM functions in various autophagic receptors such as Atg19 in the

Autophagy is a non-selective bulk degradation process in which isolation membranes enclose a portion of cytoplasm to form double-membrane vesicles, called autophagosomes, and deliver their inner constituents to the lytic compartments. Recent studies have also shed light on another mode of autophagy that selectively degrades various targets. Yeast Atg8 and its mammalian homologue LC3 are ubiquitin-like modifiers that are localized on isolation membranes and play crucial roles in the formation of

The formation of the autophagosome, a landmark event in autophagy, is accomplished by the concerted actions of Atg proteins. The initial step of starvation-induced autophagy in yeast is the assembly of the Atg1 complex, which, with the help of other Atg groups, recruits Atg conjugation systems and initiates the formation of the autophagosome. In this review, we describe from a structural-biological point of view the structure, interaction, and molecular roles of Atg proteins, especially those in

Liquid-liquid phase separation (LLPS) compartmentalizes and concentrates biomacromolecules into distinct condensates. Liquid-like condensates can transition into gel and solid states, which are essential for fulfilling their different functions. LLPS plays important roles in multiple steps of autophagy, mediating the assembly of autophagosome formation sites, acting as an unconventional modulator of TORC1-mediated autophagy regulation, and triaging protein cargos for degradation. Gel-like, but n

Autophagy is an intracellular degradation system by which cytoplasmic materials are enclosed by an autophagosome and delivered to a lysosome/vacuole. Atg18 plays a critical role in autophagosome formation as a complex with Atg2 and phosphatidylinositol 3-phosphate (PtdIns(3)P). However, little is known about the structure of Atg18 and its recognition mode of Atg2 or PtdIns(3)P. Here, we report the crystal structure of Kluyveromyces marxianus Hsv2, an Atg18 paralog, at 2.6 Å resolution. The struc

In autophagy, which is an intracellular degradation system that is conserved among eukaryotes, degradation targets are sequestered through the de novo synthesis of a double-membrane organelle, the autophagosome, which delivers them to the lysosomes for degradation. The core autophagy machinery comprising 18 autophagy-related (Atg) proteins in yeast plays an essential role in autophagosome formation; however, the molecular role of each Atg factor and the mechanism of autophagosome formation remai

Autophagosome formation, a landmark event in autophagy, is accomplished by the concerted actions of Atg proteins. Among all Atg proteins, Atg1 kinase in yeast and its counterpart in higher eukaryotes, ULK1 kinase, function as the most upstream factor in this process and mediate autophagy initiation. In this review, we summarize current knowledge of the structure, molecular function, and regulation of Atg1 family kinases in the initiation of autophagy.

ADVERTISEMENT RETURN TO ISSUEPREVReviewNEXTATG Systems from the Protein Structural Point of ViewNobuo N. Noda†, Yoshinori Ohsumi*‡, and Fuyuhiko Inagaki*†View Author Information Department of Structural Biology, Graduate School of Pharmaceutical Sciences, Hokkaido University, Sapporo 001-0021, Japan, and Division of Molecular Cell Biology, National Institute for Basic Biology, Okazaki 444-8585, Japan†Hokkaido University.‡National Institute for Basic Biology.Cite this: Chem. Rev. 2009, 109, 4, 15

Atg2 is one of the essential factors for autophagy. Recent advance of structural and biochemical study on yeast Atg2 proposed that Atg2 tethers the edge of the isolation membrane (IM) to the endoplasmic reticulum and mediates direct lipid transfer (LT) from ER to IM for IM expansion. In mammals, two Atg2 orthologs, ATG2A and ATG2B, participate in autophagic process. Here we showed that human ATG2B possesses the membrane tethering (MT) and LT activity that was promoted by negatively charged membr

Vacuolar protein sorting 30 (Vps30)/autophagy-related protein 6 (Atg6) is a common component of two distinct phosphatidylinositol 3-kinase complexes. In complex I, Atg14 links Vps30 to Vps34 lipid kinase and exerts its specific role in autophagy, whereas in complex II, Vps38 links Vps30 to Vps34 and plays a crucial role in vacuolar protein sorting. However, the molecular role of Vps30 in each pathway remains unclear. Here, we report the crystal structure of the carboxyl-terminal domain of Vps30.