Biomaterial Database

Developmental modulation of cysteine conjugate beta-lyase/glutamine transaminase K/kynurenine aminotransferase mRNA in rat brain. 1997

N Plant, and I Kitchen, and P S Goldfarb, and G G Gibson

Molecular Toxicology Group, School of Biological Sciences, University of Surrey, Guildford, UK.

Cysteine conjugate beta-lyase/glutamine transaminase K/kynurenine aminotransferase (CS-lyase/GTK/KAT) is a tri-functional enzyme found in several organs, including the brain. Kynurenine aminotransferase is important in tryptophan metabolism in the CNS, producing kynurenic acid, a NMDA receptor antagonist and neuroprotective. Tryptophan not metabolised via kynurenine aminotransferase may form quinolinic acid, a NMDA receptor agonist and neurotoxin. Kynurenic acid co-treatment blocks quinolinic acid induced lesions in the CNS in rat. In many conditions exhibiting neurodegeneration (i.e. Huntington's, Parkinsonism, Down's syndrome) quinolinic acid and/or kynurenic acid concentrations are altered, suggesting the ratio of these chemicals may be important in neurodegeneration. We have investigated the developmental modulation of CS-lyase/GTK/KAT mRNA in rat brain. CS-lyase/GTK/KAT mRNA was measured in 14, 21, 28, 35, 42 day post-natal and adult rats. While many regions demonstrated a steady increase to adult levels, two other profiles were seen. Five regions rapidly reached adult levels of the mRNA, while two peaked above the adult level before falling back. This provides evidence that expression of the CS-lyase/GTK/KAT gene is physiologically modulated, and provides the basis for further investigation into the mechanism of control. Artificial modulation could possibly be used to alter levels of the neuroprotectant kynurenic acid in neurodegeneration.

UI	MeSH Term	Description	Entries
D008190	Lyases	A class of enzymes that catalyze the cleavage of C-C, C-O, and C-N, and other bonds by other means than by hydrolysis or oxidation. (Enzyme Nomenclature, 1992) EC 4.	Desmolase,Desmolases,Lyase
D008297	Male		Males
D001921	Brain	The part of CENTRAL NERVOUS SYSTEM that is contained within the skull (CRANIUM). Arising from the NEURAL TUBE, the embryonic brain is comprised of three major parts including PROSENCEPHALON (the forebrain); MESENCEPHALON (the midbrain); and RHOMBENCEPHALON (the hindbrain). The developed brain consists of CEREBRUM; CEREBELLUM; and other structures in the BRAIN STEM.	Encephalon
D001923	Brain Chemistry	Changes in the amounts of various chemicals (neurotransmitters, receptors, enzymes, and other metabolites) specific to the area of the central nervous system contained within the head. These are monitored over time, during sensory stimulation, or under different disease states.	Chemistry, Brain,Brain Chemistries,Chemistries, Brain
D000637	Transaminases	A subclass of enzymes of the transferase class that catalyze the transfer of an amino group from a donor (generally an amino acid) to an acceptor (generally a 2-keto acid). Most of these enzymes are pyridoxyl phosphate proteins. (Dorland, 28th ed) EC 2.6.1.	Aminotransferase,Aminotransferases,Transaminase
D000818	Animals	Unicellular or multicellular, heterotrophic organisms, that have sensation and the power of voluntary movement. Under the older five kingdom paradigm, Animalia was one of the kingdoms. Under the modern three domain model, Animalia represents one of the many groups in the domain EUKARYOTA.	Animal,Metazoa,Animalia
D012333	RNA, Messenger	RNA sequences that serve as templates for protein synthesis. Bacterial mRNAs are generally primary transcripts in that they do not require post-transcriptional processing. Eukaryotic mRNA is synthesized in the nucleus and must be exported to the cytoplasm for translation. Most eukaryotic mRNAs have a sequence of polyadenylic acid at the 3' end, referred to as the poly(A) tail. The function of this tail is not known for certain, but it may play a role in the export of mature mRNA from the nucleus as well as in helping stabilize some mRNA molecules by retarding their degradation in the cytoplasm.	Messenger RNA,Messenger RNA, Polyadenylated,Poly(A) Tail,Poly(A)+ RNA,Poly(A)+ mRNA,RNA, Messenger, Polyadenylated,RNA, Polyadenylated,mRNA,mRNA, Non-Polyadenylated,mRNA, Polyadenylated,Non-Polyadenylated mRNA,Poly(A) RNA,Polyadenylated mRNA,Non Polyadenylated mRNA,Polyadenylated Messenger RNA,Polyadenylated RNA,RNA, Polyadenylated Messenger,mRNA, Non Polyadenylated
D015347	RNA Probes	RNA, usually prepared by transcription from cloned DNA, which complements a specific mRNA or DNA and is generally used for studies of virus genes, distribution of specific RNA in tissues and cells, integration of viral DNA into genomes, transcription, etc. Whereas DNA PROBES are preferred for use at a more macroscopic level for detection of the presence of DNA/RNA from specific species or subspecies, RNA probes are preferred for genetic studies. Conventional labels for the RNA probe include radioisotope labels 32P and 125I and the chemical label biotin. RNA probes may be further divided by category into plus-sense RNA probes, minus-sense RNA probes, and antisense RNA probes.	Gene Probes, RNA,RNA Probe,Probe, RNA,Probes, RNA,Probes, RNA Gene,RNA Gene Probes
D015971	Gene Expression Regulation, Enzymologic	Any of the processes by which nuclear, cytoplasmic, or intercellular factors influence the differential control of gene action in enzyme synthesis.	Enzymologic Gene Expression Regulation,Regulation of Gene Expression, Enzymologic,Regulation, Gene Expression, Enzymologic
D017208	Rats, Wistar	A strain of albino rat developed at the Wistar Institute that has spread widely at other institutions. This has markedly diluted the original strain.	Wistar Rat,Rat, Wistar,Wistar Rats