Guerra-Giraldez Cristina, Quijada Luis, Clayton Christine E
Zentrum für Molekulare Biologie der Universität Heidelberg, Im Neuenheimer Feld 282, D-69120 Heidelberg, Germany.
J Cell Sci. 2002 Jul 1;115(Pt 13):2651-8. doi: 10.1242/jcs.115.13.2651.
All kinetoplastids contain membrane-bound microbodies known as glycosomes, in which several metabolic pathways including part of glycolysis are compartmentalized. Peroxin 2 is essential for the import of many proteins into the microbodies of yeasts and mammals. The PEX2 gene of Trypanosoma brucei was identified and its expression was silenced by means of tetracycline-inducible RNA interference. Bloodstream-form trypanosomes, which rely exclusively on glycolysis for ATP generation, died rapidly upon PEX2 depletion. Insect-form (procyclic) trypanosomes do not rely solely on glycolysis for ATP synthesis. PEX2 depletion in procyclic forms resulted in relocation of most tested matrix proteins to the cytosol, and these mutants also died. Compartmentation of microbody enzymes is therefore essential for survival of bloodstream and procyclic T. brucei. In contrast, yeasts and cultured mammalian cells grow normally in the absence of peroxisomal membranes unless placed on selective media.
所有动基体目生物都含有被称为糖体的膜结合微体，其中包括部分糖酵解在内的多种代谢途径被分隔开来。过氧化物酶2对于许多蛋白质导入酵母和哺乳动物的微体至关重要。布氏锥虫的PEX2基因已被鉴定，并且其表达通过四环素诱导的RNA干扰被沉默。仅依靠糖酵解产生ATP的血流形式锥虫，在PEX2缺失后迅速死亡。昆虫形式（前循环型）锥虫并非仅依靠糖酵解来合成ATP。前循环型锥虫中PEX2的缺失导致大多数测试的基质蛋白重新定位到细胞质中，并且这些突变体也死亡。因此，微体酶的区室化对于血流形式和前循环型布氏锥虫的存活至关重要。相比之下，酵母和培养的哺乳动物细胞在没有过氧化物酶体膜的情况下通常能正常生长，除非置于选择性培养基上。
