Chandoga J, Petrovic R
Centrum lekárskej genetiky FN, Bratislava.
Cas Lek Cesk. 2001 Jan 19;140(1):8-12.
Peroxisomes represent cell organelles present in both unicellular eukaryotes and most of the animal and plant cells. Peroxisomes contain about 50 enzymes with high variability in spectrum and quantity, depending on nutritional conditions and presence of some xenobiotics (peroxisome proliferations). New peroxisomes are formed after the protein intake by splitting of the existing peroxisomes or de novo. Biogenesis of peroxisomes requires cytosolic proteins, membrane transporting proteins, and the typical groups of amino acids in polypeptide chains, which have the character of topogenic signal--PTS (peroxisomal targeting signal). PTS signal is based on the terminal tripeptide, formed usually by amino acids serine, lysine and leucine (SKL tripeptide--PTS1) or by the N-terminal PTS2 with amino acid sequence Arg-Leu/Ile-XXXXX-Gln/His-Leu (X is any amino acid). Biogenesis of peroxisomes requires also special membrane proteins--peroxins, which are coded by PEX genes. These proteins act as homo- or heterodimes, they belong to ATP transports, and determine efficacy of the peroxisome biogenesis. Nuclear gene expression is regulated by nuclear receptors activated by peroxisome proliferators (PPAR-proxisome proliferators activated receptors). C-domain of the receptor binds to the specific region of the promotors of peroxisome genes (PPREs-Peroxisomal proliferator response elements), often with tandem arrangement of sequences TGACCT. Polyunsaturated fatty acids represent the effective natural regulator of the peroxisomal gene expression.
过氧化物酶体是存在于单细胞真核生物以及大多数动植物细胞中的细胞器。过氧化物酶体含有约50种酶，其种类和数量变化很大，这取决于营养状况和某些外源生物的存在（过氧化物酶体增殖）。新的过氧化物酶体在摄入蛋白质后通过现有过氧化物酶体的分裂或从头合成形成。过氧化物酶体的生物发生需要胞质蛋白、膜转运蛋白以及多肽链中具有拓扑信号特征的典型氨基酸基团——PTS（过氧化物酶体靶向信号）。PTS信号基于末端三肽，通常由丝氨酸、赖氨酸和亮氨酸组成（SKL三肽——PTS1），或者由具有氨基酸序列Arg-Leu/Ile-XXXXX-Gln/His-Leu的N端PTS2组成（X为任意氨基酸）。过氧化物酶体的生物发生还需要特殊的膜蛋白——过氧化物酶，它们由PEX基因编码。这些蛋白以同二聚体或异二聚体形式发挥作用，属于ATP转运蛋白，决定过氧化物酶体生物发生的效率。核基因表达受过氧化物酶体增殖物激活的核受体（PPAR——过氧化物酶体增殖物激活受体）调控。受体的C结构域与过氧化物酶体基因启动子的特定区域（PPREs——过氧化物酶体增殖物反应元件）结合，这些序列通常呈TGACCT串联排列。多不饱和脂肪酸是过氧化物酶体基因表达的有效天然调节剂。
