Sibirny Andriy A
Department of Molecular Genetics and Biotechnology, Institute of Cell Biology, NAS of Ukraine, Drahomanov Street, 14/16, Lviv 79005, Ukraine Department of Biotechnology and Microbiology, University of Rzeszow, Zelwerowicza 4, Rzeszow 35-601, Poland
FEMS Yeast Res. 2016 Jun;16(4). doi: 10.1093/femsyr/fow038. Epub 2016 Apr 12.
Peroxisomes are ubiquitous organelles found in most eukaryotic cells. In yeasts, peroxisomes play important roles in cell metabolism, especially in different catabolic processes including fatty acid β-oxidation, the glyoxylic shunt and methanol metabolism, as well as some biosynthetic processes. In addition, peroxisomes are the compartment in which oxidases and catalase are localized. New peroxisomes mainly arise by fission of pre-existing ones, although they can also be formed from the endoplasmic reticulum (ER). Peroxisomes consist of matrix-soluble proteins and membrane proteins known as peroxins. A total of 34 PEX peroxin genes and proteins have been identified to date. and their functions have been elucidated. Protein import into peroxisomes depends on peroxins and requires specific signals in the structure of transported proteins: PTS1, PTS2 and mPTS. The mechanisms of metabolite penetration into peroxisomes are still poorly understood. Peroxisome number and the volume occupied by these organelles are tightly regulated. Methanol, fatty acids and methylamine act as efficient peroxisome proliferators, whereas glucose and ethanol induce peroxisome autophagic degradation (pexophagy). To date, 42 Atg proteins involved in pexophagy are known. Catabolism and alcoholic fermentation of the major pentose sugar, xylose, depend on peroxisomal enzymes. Overexpression of peroxisomal transketolase and transaldolase activates xylose fermentation. Peroxisomes could be useful as target organelles for overexpression of foreign toxic proteins.
过氧化物酶体是存在于大多数真核细胞中的普遍存在的细胞器。在酵母中，过氧化物酶体在细胞代谢中发挥重要作用，特别是在不同的分解代谢过程中，包括脂肪酸β-氧化、乙醛酸循环和甲醇代谢，以及一些生物合成过程。此外，过氧化物酶体是氧化酶和过氧化氢酶定位的区室。新的过氧化物酶体主要通过已存在的过氧化物酶体的分裂产生，尽管它们也可以由内质网（ER）形成。过氧化物酶体由基质可溶性蛋白和称为过氧化物酶的膜蛋白组成。迄今为止，总共已鉴定出34个PEX过氧化物酶基因和蛋白，并且它们的功能已得到阐明。蛋白质导入过氧化物酶体依赖于过氧化物酶，并且需要转运蛋白结构中的特定信号：PTS1、PTS2和mPTS。代谢物渗透到过氧化物酶体中的机制仍知之甚少。过氧化物酶体的数量和这些细胞器所占的体积受到严格调控。甲醇、脂肪酸和甲胺作为有效的过氧化物酶体增殖剂，而葡萄糖和乙醇诱导过氧化物酶体自噬降解（pexophagy）。迄今为止，已知有42种参与pexophagy的Atg蛋白。主要戊糖木糖的分解代谢和酒精发酵依赖于过氧化物酶体酶。过氧化物酶体转酮醇酶和转醛醇酶的过表达激活木糖发酵。过氧化物酶体可用作外源毒性蛋白过表达的靶细胞器。
