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Literature summary for 1.3.8.4 extracted from

  • Hirota, T.; Izumi, M.; Wada, S.; Makino, A.; Ishida, H.
    Vacuolar protein degradation via autophagy provides substrates to amino acid catabolic pathways as an adaptive response to sugar starvation in Arabidopsis thaliana (2018), Plant Cell Physiol., 59, 1363-1376 .
    View publication on PubMed
Search for more literature for 1.3.8.4

Protein Variants

Protein Variants Comment Organism
additional information knockout mutants atg10-1, atg5-1, and atg2-1, as well as ivdh-1 and etfqo-1 mutants, phenotypes, overview. Dark-induced increases in specific amino acid levels are compromised in atg mutants. Comparison of the amino acid levels between ivdh-1 or etfqo-1 mutants and the wild-type shows that total amino acid levels increase similarly after the dark treatment among those plants, mainly caused by increases in the BCAAs, basic amino acids, aromatic amino acids and Asn. The dark-induced increase of Glu is suppressed in ivdh-1 and etfqo-1. Among the individual amino acids that do not increase in the dark-treated wild-type, the decrease in alanine levels is exacerbated in both ivdh-1 and etfqo-1. These results show the attenuation of BCAA catabolism in the mutants. The accumulation of BCAAs after 2 days of dark treatment is enhanced in ivdh-1 and etfqo-1 compared with to wild-type supporting the suggestion that BCAAs are catabolized via IVDH and the ETF/ETFQO system from an early period of dark treatment. The ivdh-1 and etfqo-1 mutations do not affect the dark-induced increases in the levels of basic amino acids (Lys, Arg, and His) and aromatic amino acids (Phe, Tyr, and Trp) compared with to wild-type plants Arabidopsis thaliana

Localization

Localization Comment Organism GeneOntology No. Textmining
chloroplast stroma
-
 Arabidopsis thaliana 9570
-

Natural Substrates/ Products (Substrates)

Natural Substrates Organism Comment (Nat. Sub.) Natural Products Comment (Nat. Pro.) Rev. Reac.
isovaleryl-CoA + electron-transfer flavoprotein Arabidopsis thaliana
-
 3-methylcrotonyl-CoA + reduced electron-transfer flavoprotein
-
 ?
isovaleryl-CoA + electron-transfer flavoprotein Arabidopsis thaliana Col-0
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 3-methylcrotonyl-CoA + reduced electron-transfer flavoprotein
-
 ?

Organism

Organism UniProt Comment Textmining
Arabidopsis thaliana Q9SWG0
-
-
Arabidopsis thaliana Col-0 Q9SWG0
-
-

Source Tissue

Source Tissue Comment Organism Textmining
leaf mature Arabidopsis thaliana
-

Substrates and Products (Substrate)

Substrates Comment Substrates Organism Products Comment (Products) Rev. Reac.
isovaleryl-CoA + electron-transfer flavoprotein
-
 Arabidopsis thaliana 3-methylcrotonyl-CoA + reduced electron-transfer flavoprotein
-
 ?
isovaleryl-CoA + electron-transfer flavoprotein
-
 Arabidopsis thaliana Col-0 3-methylcrotonyl-CoA + reduced electron-transfer flavoprotein
-
 ?

Synonyms

Synonyms Comment Organism
IVD
-
 Arabidopsis thaliana
IVDH
-
 Arabidopsis thaliana

Cofactor

Cofactor Comment Organism Structure
electron transferring flavoprotein ETF Arabidopsis thaliana

Expression

Organism Comment Expression
Arabidopsis thaliana transcript levels of BCAT2, BCKDH E1A1, IVDH and ETFQO are increased after the 2 days dark treatment in both the wild-type and the atg5-1 mutant up

General Information

General Information Comment Organism
malfunction during sugar starvation arising from the exposure of wild-type plants to darkness, autophagic transport of chloroplast stroma, which contains most of the proteins in a leaf, into the vacuolar lumen is induced within 2 days. During this time, the level of soluble proteins, primarily Rubisco (ribulose-1,5-bisphosphate carboxylase/oxygenase), decreases and the amount of free amino acid increases. In dark-treated autophagy-defective (atg) mutants, the decrease of soluble proteins is suppressed, which results in the compromised release of basic amino acids, branched-chain amino acids (BCAAs) and aromatic amino acids. The impairment of BCAA catabolic pathways in the knockout mutants of the electron transfer flavoprotein (ETF)/ETF:ubiquinone oxidoreductase (etfqo) complex and the electron donor protein isovaleryl-CoA dehydrogenase (ivdh) cause a reduced tolerance to dark treatment similar to that in the atg mutants. The enhanced accumulation of BCAAs in the ivdh and etfqo mutants during the dark treatment is reduced by additional autophagy deficiency. These results indicate that vacuolar protein degradation via autophagy serves as an adaptive response to disrupted photosynthesis by providing substrates to amino acid catabolic pathways, including BCAA catabolism mediated by IVDH and ETFQO. Knockout mutants atg10-1, atg5-1, and atg2-1, phenotypes, overview Arabidopsis thaliana
metabolism BCAA transaminase 2 (BCAT2) and the branched-chain alpha2-oxo acid dehydrogenase complex subunit E1A1 (BCKDH E1A1) are involved in BCAA catabolism by providing substrates to enzyme IVDH. During sugar starvation arising from the exposure of wild-type plants to darkness, autophagic transport of chloroplast stroma, which contains most of the proteins in a leaf, into the vacuolar lumen is induced within 2 days. During this time, the level of soluble proteins, primarily Rubisco (ribulose-1,5-bisphosphate carboxylase/oxygenase), decreases and the amount of free amino acid increases. Vacuolar protein degradation via autophagy serves as an adaptive response to disrupted photosynthesis by providing substrates to amino acid catabolic pathways, including BCAA catabolism mediated by IVDH and ETFQO, involving the isovaleryl-CoA dehydrogenase (ivdh). Autophagy and amino acid catabolism are important in the plant response to sugar starvation. Relationship between autophagy and amino acid catabolism via the ETF/ETFQO system, overview Arabidopsis thaliana