ATG14 promotes membrane tethering and fusion of autophagosomes to endolysosomes.
ATG14 promotes membrane tethering and fusion of autophagosomes to endolysosomes.
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DOI：
10.1038/nature14147
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发表时间：
2015-04-23
期刊：
影响因子：
64.8
通讯作者：
Zhong, Qing
中科院分区：
文献类型：
--
作者：
Diao, Jiajie;Liu, Rong;Rong, Yueguang;Zhao, Minglei;Zhang, Jing;Lai, Ying;Zhou, Qiangjun;Wilz, Livia M.;Li, Jianxu;Vivona, Sandro;Pfuetzner, Richard A.;Brunger, Axel T.;Zhong, Qing
自噬是一种重要的分解代谢途径，与多种人类疾病有关，它始于形成吞噬细胞质货物的双膜自噬体，并以自噬体与溶酶体融合降解为终点。膜融合活性是自噬体的早期生物发生和溶酶体中的晚期降解所必需的。然而，自噬膜束缚和融合的关键调控机制仍然在很大程度上未知。在此我们报告ATG 14（也称为beclin-1相关的自噬相关关键调节因子（Barkor）或ATG 14 L），III类磷脂酰肌醇3-激酶复合物的必需的自噬特异性调节因子，促进无蛋白脂质体的膜束缚，并增强与靶（t）-SNARE重建的脂蛋白体的半融合和完全融合（可溶性N-乙基马来酰亚胺敏感因子附着蛋白受体）突触融合蛋白17（STX 17）和SNAP 29，以及囊泡（v）-SNARE VAMP 8（囊泡相关膜蛋白8）。ATG 14通过卷曲螺旋结构域与STX 17的SNARE核心结构域结合，并稳定自噬体上的STX 17-SNAP 29二元t-SNARE复合物。ATG 14的STX 17结合、膜束缚和融合增强活性需要其通过半胱氨酸重复的同源寡聚化。在ATG 14同源寡聚化缺陷型细胞中，自噬体仍然有效地形成，但其与内溶酶体的融合被阻断。重组ATG 14同源寡聚化突变体也完全丧失了它们促进膜束缚和增强SNARE介导的体外融合的能力。综上所述，我们的研究结果提示了一种自噬特异性的膜融合机制，其中寡聚ATG 14直接结合自噬体上的STX 17-SNAP 29二元t-SNARE复合物，并引发其与VAMP 8相互作用，从而促进自噬体-内溶酶体融合。
Autophagy, an important catabolic pathway implicated in a broad spectrum of human diseases, begins by forming double membrane autophagosomes that engulf cytosolic cargo and ends by fusing autophagosomes with lysosomes for degradation. Membrane fusion activity is required for early biogenesis of autophagosomes and late degradation in lysosomes. However, the key regulatory mechanisms of autophagic membrane tethering and fusion remain largely unknown. Here we report that ATG14 (also known as beclin-1-associated autophagy-related key regulator (Barkor) or ATG14L), an essential autophagy-specific regulator of the class III phosphatidylinositol 3-kinase complex, promotes membrane tethering of protein-free liposomes, and enhances hemifusion and full fusion of proteoliposomes reconstituted with the target (t)-SNAREs (soluble N-ethylmaleimide-sensitive factor attachment protein receptors) syntaxin 17 (STX17) and SNAP29, and the vesicle (v)-SNARE VAMP8 (vesicle-associated membrane protein 8). ATG14 binds to the SNARE core domain of STX17 through its coiled-coil domain, and stabilizes the STX17–SNAP29 binary t-SNARE complex on autophagosomes. The STX17 binding, membrane tethering and fusion-enhancing activities of ATG14 require its homo-oligomerization by cysteine repeats. In ATG14 homo-oligomerization-defective cells, autophagosomes still efficiently form but their fusion with endolysosomes is blocked. Recombinant ATG14 homo-oligomerization mutants also completely lose their ability to promote membrane tethering and to enhance SNARE-mediated fusion in vitro. Taken together, our data suggest an autophagy-specific membrane fusion mechanism in which oligomeric ATG14 directly binds to STX17–SNAP29 binary t-SNARE complex on autophagosomes and primes it for VAMP8 interaction to promote autophagosome–endolysosome fusion.
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影响因子：
14.8
作者：
通讯作者：
--
影响因子：
4.8
作者：
Strop, Pavel;Kaiser, Stephen E.;Brunger, Axel T.
通讯作者：
Brunger, Axel T.
DOI：
10.1107/s0907444904019158
发表时间：
2004-12-01
影响因子：
2.2
作者：
Emsley, P;Cowtan, K
通讯作者：
Cowtan, K
影响因子：
64.5
作者：
Nakatogawa, Hitoshi;Ichimura, Yoshinobu;Ohsumi, Yoshinori
通讯作者：
Ohsumi, Yoshinori
DOI：
10.1107/s0907444909052925
发表时间：
2010-02
期刊：
Acta crystallographica. Section D, Biological crystallography
影响因子：
--
作者：
Adams PD;Afonine PV;Bunkóczi G;Chen VB;Davis IW;Echols N;Headd JJ;Hung LW;Kapral GJ;Grosse-Kunstleve RW;McCoy AJ;Moriarty NW;Oeffner R;Read RJ;Richardson DC;Richardson JS;Terwilliger TC;Zwart PH
通讯作者：
Zwart PH