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-Structure paper
タイトル | Structure of yeast Ape1 and its role in autophagic vesicle formation. |
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ジャーナル・号・ページ | Autophagy, Vol. 11, Issue 9, Page 1580-1593, Year 2015 |
掲載日 | 2016年6月20日 |
著者 | Ming-Yuan Su / Wen-Hsin Peng / Meng-Ru Ho / Shih-Chieh Su / Yuan-Chih Chang / Guang-Chao Chen / Chung-I Chang / |
PubMed 要旨 | In Saccharomyces cerevisiae, a constitutive biosynthetic transport pathway, termed the cytoplasm-to-vacuole targeting (Cvt) pathway, sequesters precursor aminopeptidase I (prApe1) dodecamers in the ...In Saccharomyces cerevisiae, a constitutive biosynthetic transport pathway, termed the cytoplasm-to-vacuole targeting (Cvt) pathway, sequesters precursor aminopeptidase I (prApe1) dodecamers in the form of a large complex into a Cvt vesicle using autophagic machinery, targeting it into the vacuole (the yeast lysosome) where it is proteolytically processed into its mature form, Ape1, by removal of an amino-terminal 45-amino acid propeptide. prApe1 is thought to serve as a scaffolding cargo critical for the assembly of the Cvt vesicle by presenting the propeptide to mediate higher-ordered complex formation and autophagic receptor recognition. Here we report the X-ray crystal structure of Ape1 at 2.5 Å resolution and reveal its dodecameric architecture consisting of dimeric and trimeric units, which associate to form a large tetrahedron. The propeptide of prApe1 exhibits concentration-dependent oligomerization and forms a stable tetramer. Structure-based mutagenesis demonstrates that disruption of the inter-subunit interface prevents dodecameric assembly and vacuolar targeting in vivo despite the presence of the propeptide. Furthermore, by examining the vacuolar import of propeptide-fused exogenous protein assemblies with different quaternary structures, we found that 3-dimensional spatial distribution of propeptides presented by a scaffolding cargo is essential for the assembly of the Cvt vesicle for vacuolar delivery. This study describes a molecular framework for understanding the mechanism of Cvt or autophagosomal biogenesis in selective macroautophagy. |
リンク | Autophagy / PubMed:26208681 / PubMed Central |
手法 | EM (単粒子) / X線回折 |
解像度 | 2.5 - 19.0 Å |
構造データ | EMDB-6265: PDB-4r8f: |
化合物 | ChemComp-HOH: |
由来 |
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キーワード | HYDROLASE (加水分解酵素) / peptidase (プロテアーゼ) / Cvt pathway / Autophagy (オートファジー) |