PEX34, encoding a peroxisomal protein implicated in regulating peroxisome numbers, was identified as a high copy suppressor, capable of bypassing impaired acetate utilization of agc1∆ yeast. However, improved growth of agc1∆ yeast on acetate is not mediated through peroxisome proliferation. Instead, stress to the endoplasmic reticulum and mitochondria from PEX34 overexpression appears to contribute to enhanced acetate utilization of agc1∆ yeast. The citrate/2-oxoglutarate carrier Yhm2p is required for PEX34 stimulated growth of agc1∆ yeast on acetate medium, suggesting that the suppressor effect is mediated through increased activity of a redox shuttle involving mitochondrial citrate export. Metabolomic analysis also revealed redirection of acetyl-coenzyme A (CoA) from synthetic reactions for amino acids in PEX34 overexpressing yeast. We propose a model in which increased formation of products from the glyoxylate shunt, together with enhanced utilization of acetyl-CoA, promotes the activity of an alternative mitochondrial redox shuttle, partially substituting for loss of yeast AGC1.

中文翻译：

---

过氧化物酶Pex34p的过表达抑制了缺乏线粒体天冬氨酸/谷氨酸载体Agc1p的酵母中乙酸盐利用的受损。

PEX34编码一种过氧化物酶体蛋白，与调节过氧化物酶体数目有关，被认为是一种高拷贝抑制因子，能够绕过agc1Δ酵母的醋酸盐利用受损。但是，agc1Δ酵母在醋酸盐上生长的改善不是通过过氧化物酶体增殖来介导的。相反，过表达PEX34对内质网和线粒体的压力似乎有助于提高agc1Δ酵母的乙酸盐利用率。柠檬酸/ 2-氧戊二酸载体Yhm2p是醋酸盐培养基上PEX34刺激的agc1Δ酵母生长所必需的，这表明抑制作用是通过涉及线粒体柠檬酸输出的氧化还原穿梭的活性增加来介导的。代谢组学分析还揭示了乙酰辅酶A（CoA）从PEX34过表达酵母中氨基酸合成反应中的重定向。