Molecular Cell Biology, Groningen Biomolecular Sciences and Biotechnology Institute, University of Groningen, The Netherlands.
Biochem Biophys Res Commun. 2013 Aug 23;438(2):395-401. doi: 10.1016/j.bbrc.2013.07.086. Epub 2013 Jul 27.
Peroxisome autophagy, also known as pexophagy, describes the wholesale degradation of peroxisomes via the vacuole, when organelles become damaged or redundant. In the methylotrophic yeast Hansenula polymorpha, pexophagy is stimulated when cells growing on methanol are exposed to excess glucose. Degradation of the peroxisomal membrane protein Pex3p, a process that does not involve the vacuole, was shown to trigger pexophagy. In this contribution, we have characterised pexophagy-associated Pex3p degradation further. We show that Pex3p breakdown depends on ubiquitin and confirm that Pex3p is a target for ubiquitination. Furthermore, we identify a role for the peroxisomal E3 ligases Pex2p and Pex10p in Pex3p degradation, suggesting the existence of a ubiquitin-dependent pathway involved in removing proteins from the peroxisomal membrane.
过氧化物酶体自噬，也称为pexophagy，描述了过氧化物体通过液泡的批量降解，当细胞器受损或冗余时。在甲醇营养型酵母汉逊德巴利酵母中，当在甲醇上生长的细胞暴露于过量葡萄糖时，pexophagy 会受到刺激。过氧化物体膜蛋白 Pex3p 的降解过程不涉及液泡，被证明会引发 pexophagy。在本研究中，我们进一步研究了与pexophagy 相关的 Pex3p 降解。我们表明 Pex3p 的分解依赖于泛素，并证实 Pex3p 是泛素化的靶标。此外，我们发现过氧化物体 E3 连接酶 Pex2p 和 Pex10p 在 Pex3p 降解中起作用，这表明存在一种依赖泛素的途径，用于从过氧化物体膜上去除蛋白质。
