Overexpression of the peroxin Pex34p suppresses impaired acetate utilization in yeast lacking the mitochondrial aspartate/glutamate carrier Agc1p. Issue 8 (11th November 2019)

• Record Type: Journal Article
• Authors: Chalermwat, Chalongchai; Thosapornvichai, Thitipa; Wongkittichote, Parith; Phillips, John D; Cox, James E; Jensen, Amornrat N; Wattanasirichaigoon, Duangrurdee; Jensen, Laran T
• Is Part Of: FEMS yeast research. Volume 19:Issue 8(2019)
• Publication Date: 2019-11-11
• Subjects: aspartate-glutamate carrier -- peroxin -- PEX34 -- suppressor -- acetate utilization -- AGC1; Yeast -- Periodicals; Yeasts -- Periodicals; 579.562
• DOI: 10.1093/femsyr/foz078
• Languages: English
• ISSNs: 1567-1356

Abstract

ABSTRACT: 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 . Abstract : Bypass of aspartate-glutamate carrier deficiency through overexpression of the peroxin PEX34 is mediated by redirection of acetyl-CoA toward energy production together with utilization of an alternative mitochondrial redox shuttle.