scholarly journals Stoichiometry of two plant glycine decarboxylase complexes and comparison with a cyanobacterial glycine cleavage system

2020 ◽  
Vol 103 (2) ◽  
pp. 801-813
Author(s):  
Maria Wittmiß ◽  
Stefan Mikkat ◽  
Martin Hagemann ◽  
Hermann Bauwe
Keyword(s):  
Glycine Decarboxylase ◽  
Glycine Cleavage System ◽  
Glycine Cleavage

scholarly journals Effects of tetrahydrofolate polyglutamates on the kinetic parameters of serine hydroxymethyltransferase and glycine decarboxylase from pea leaf mitochondria

1993 ◽  
Vol 292 (2) ◽  
pp. 425-430 ◽  
Author(s):  
V Besson ◽  
F Rebeille ◽  
M Neuburger ◽  
R Douce ◽  
E A Cossins
Keyword(s):  
Kinetic Parameters ◽  
Serine Hydroxymethyltransferase ◽  
Affinity Constant ◽  
Plant Tissues ◽  
Glycine Decarboxylase ◽  
Glycine Cleavage System ◽  
Matrix Space ◽  
The Matrix ◽  
Order Of Magnitude ◽  
Glycine Cleavage

Plant tissues contain highly conjugated forms of folate. Despite this, the ability of plant folate-dependent enzymes to utilize tetrahydrofolate polyglutamates has not been examined in detail. In leaf mitochondria, the glycine-cleavage system and serine hydroxymethyltransferase, present in large amounts in the matrix space and involved in the photorespiratory cycle, necessitate the presence of tetrahydrofolate as a cofactor. The aim of the present work was to determine whether glutamate chain length (one to six glutamate residues) influenced the affinity constant for tetrahydrofolate and the maximal velocities displayed by these two enzymes. The results show that the affinity constant decreased by at least one order of magnitude when the tetrahydrofolate substrate contained three or more glutamate residues. In contrast, maximal velocities were not altered in the presence of these substrates. These results are consistent with analyses of mitochondrial folates which revealed a pool of polyglutamates dominated by tetra and pentaglutamates. The equilibrium constant of the serine hydroxymethyltransferase suggests that, during photorespiration, the reaction must be permanently pushed toward the formation of serine (the unfavourable direction) to allow the recycling of tetrahydrofolate necessary for the operation of the glycine decarboxylase T-protein.

scholarly journals mTORC1 activity regulates post-translational modifications of glycine decarboxylase to modulate glycine metabolism and tumorigenesis

2021 ◽  
Vol 12 (1) ◽  
Author(s):  
Rui Liu ◽  
Lin-Wen Zeng ◽  
Rong Gong ◽  
Fanen Yuan ◽  
Hong-Bing Shu ◽  
...  
Keyword(s):  
Enzymatic Activity ◽  
Ubiquitin Ligase ◽  
Glycine Decarboxylase ◽  
Glycine Cleavage System ◽  
Sirtuin 3 ◽  
Post Translational Modifications ◽  
Mechanistic Target Of Rapamycin ◽  
Glycine Metabolism ◽  
Key Enzyme ◽  
Glycine Cleavage

AbstractGlycine decarboxylase (GLDC) is a key enzyme of glycine cleavage system that converts glycine into one-carbon units. GLDC is commonly up-regulated and plays important roles in many human cancers. Whether and how GLDC is regulated by post-translational modifications is unknown. Here we report that mechanistic target of rapamycin complex 1 (mTORC1) signal inhibits GLDC acetylation at lysine (K) 514 by inducing transcription of the deacetylase sirtuin 3 (SIRT3). Upon inhibition of mTORC1, the acetyltransferase acetyl-CoA acetyltransferase 1 (ACAT1) catalyzes GLDC K514 acetylation. This acetylation of GLDC impairs its enzymatic activity. In addition, this acetylation of GLDC primes for its K33-linked polyubiquitination at K544 by the ubiquitin ligase NF-X1, leading to its degradation by the proteasomal pathway. Finally, we find that GLDC K514 acetylation inhibits glycine catabolism, pyrimidines synthesis and glioma tumorigenesis. Our finding reveals critical roles of post-translational modifications of GLDC in regulation of its enzymatic activity, glycine metabolism and tumorigenesis, and provides potential targets for therapeutics of cancers such as glioma.

scholarly journals Mutation analysis of glycine decarboxylase, aminomethyltransferase and glycine cleavage system protein-H genes in 13 unrelated families with glycine encephalopathy

2014 ◽  
Vol 59 (11) ◽  
pp. 593-597 ◽  
Author(s):  
Nor Azimah Abdul Azize ◽  
Wan Zurinah Wan Ngah ◽  
Zulhabri Othman ◽  
Norsiah Md Desa ◽  
Chen Bee Chin ◽  
...  
Keyword(s):  
Mutation Analysis ◽  
Glycine Decarboxylase ◽  
Glycine Cleavage System ◽  
Glycine Encephalopathy ◽  
Glycine Cleavage
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