Metabolic regulation at the tricarboxylic acid and glyoxylate cycles of the lignin-degrading basidiomycete Phanerochaete chrysosporium against exogenous addition of vanillin.
A proteomic differential display technique was utilized to study cellular responses of Phanerochaete chrysosporium exposed to vanillin, one of the key intermediates found during lignin biodegradation. Intracellular proteins were resolved by 2-DE and target protein spots were identified using MALDI-MS after in-gel tryptic digestions. Upon addition of vanillin to P. chrysosporium, up-regulation of homogentisate 1,2-dioxygenase, 1,4-benzoquinone reductases, aldehyde dehydrogenase, and aryl-alcohol dehydrogenase, which seem to play roles in vanillin metabolism, was observed. Furthermore, enzymes involved in glycolysis, the tricarboxylic acid cycle, the pentose-phosphate cycle, and heme biosynthesis were also activated. Up-regulation of extracellular peroxidase was also observed. One of the most unique phenomena against exogenous vanillin was a switch from the glyoxylate cycle to the tricarboxylic acid cycle, where a drastic increase in isocitrate dehydrogenase activity was observed. The exogenous addition of other aromatic compounds also caused an increase in its activity, which in turn triggered NAD(P)H production via the action of dehydrogenases in the tricarboxylic acid cycle, heme biosynthesis via the action of aminolevulinic acid synthase on succinyl-CoA, and energy production via activation of the mitochondrial electron transfer system. These metabolic shifts seem to be required for activating a metabolic system for aromatic compounds.
Shimizu
Motoyuki
M
Faculty of Agriculture, Kyushu University, Fukuoka, Japan.
Yuda
Naoki
N
Nakamura
Tomofumi
T
Tanaka
Hiroo
H
Wariishi
Hiroyuki
H
D000429:Alcohol Oxidoreductases / Q000378:metabolism; D000444:Aldehyde Dehydrogenase / Q000378:metabolism; D001487:Basidiomycota / Q000378:metabolism*; D001547:Benzaldehydes / Q000378:metabolism* / Q000494:pharmacology*; D001673:Biodegradation, Environmental; D002952:Citric Acid Cycle; D004789:Enzyme Activation; D015971:Gene Expression Regulation, Enzymologic; D015966:Gene Expression Regulation, Fungal; D006038:Glyoxylates / Q000378:metabolism*; D007522:Isocitrate Lyase / Q000378:metabolism*; D008031:Lignin / Q000378:metabolism*; D010544:Peroxidases; D020075:Phanerochaete / Q000187:drug effects / Q000378:metabolism*; D011506:Proteins / Q000378:metabolism; D020133:Reverse Transcriptase Polymerase Chain Reaction; D019032:Spectrometry, Mass, Matrix-Assisted Laser Desorption-Ionization; D015854:Up-Regulation
D001547:Benzaldehydes; D006038:Glyoxylates; D011506:Proteins; D008031:Lignin; C100058:vanillin; D000429:Alcohol Oxidoreductases; C055882:aryl-alcohol dehydrogenase; D010544:Peroxidases; D000444:Aldehyde Dehydrogenase; D007522:Isocitrate Lyase; C031150:glyoxylic acid