Interaction between chaperone and protease functions of LON2, and autophagy during the functional transition of peroxisomes
Interaction between chaperone and protease functions of LON2, and autophagy during the functional transition of peroxisomes
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DOI：
10.4161/psb.28838
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发表时间：
2014-01-01
影响因子：
2.9
通讯作者：
Nishimura, Mikio
中科院分区：
文献类型：
--
作者：
Goto-Yamada, Shino;Mano, Shoji;Nishimura, Mikio
在绿化子叶中观察到乙醛酶体向叶片过氧化物酶体的功能转变。子叶暴露于光后，Glyoxysomal proteins被迅速降解，叶片-过氧化物酶体protein被转运到过氧化物酶体中，但这些过程的分子机制尚不清楚。我们最近在拟南芥中发现了两种降解途径参与过氧化物酶体的功能转变。长链蛋白酶2 （LON2）负责降解过氧化物酶体内的glyoxysomal protein，与此同时，自噬消除了受损或过时的过氧化物酶体。在子叶变绿后，在lon2和自噬依赖性降解途径中都存在缺陷的双突变体积累了glyoxysomal proteins。我们的研究还表明，LON2和自噬依赖途径是相互依赖的，LON2的伴侣功能抑制自噬过氧化物酶体的降解。此外，LON2的肽酶结构域干扰了自噬的抑制，表明自噬是通过LON2的蛋白水解和伴侣功能之间的分子内调节来调节的。
Functional transition of glyoxysomes to leaf peroxisomes is observed in greening cotyledons. Glyoxysomal proteins are rapidly degraded and leaf-peroxisomal proteins are transported into peroxisomes after cotyledons are exposed to light, but the molecular mechanisms underlying these processes remain unclear. We recently discovered that two degradation pathways are involved in the functional transition of peroxisomes using Arabidopsis thaliana. Lon protease 2 (LON2) is responsible for the degradation of glyoxysomal proteins inside peroxisomes, and, in parallel, autophagy eliminates damaged or obsolete peroxisomes. A double mutant defective in both the LON2and autophagy-dependent degradation pathways accumulated glyoxysomal proteins after the cotyledons became green. Our study also demonstrated that the LON2-and autophagy-dependent pathways are interdependent, with the chaperone function of LON2 suppressing autophagic peroxisome degradation. Moreover, the peptidase domain of LON2 interferes with the suppression of autophagy, indicating that autophagy is regulated by intramolecular modulation between the proteolysis and chaperone functions of LON2.