The effects of environmental stress on cholesterol synthesis and metabolism
10
Citation
4
Reference
10
Related Paper
Citation Trend
Keywords:
Environmental stress
Cellular respiration
Cite
Citations (16)
Reverse cholesterol transport
Cite
Citations (50)
Cite
Citations (21)
Amino acid metabolism lies at the crossroad between nitrogen assimilation, carbon fixation and secondary metabolism. Because of this central position in plant metabolism, amino acid metabolism is tightly regulated by numerous factors to match both demand from the organs and availability of reduced carbon and inorganic nitrogen. While the amino acid biosynthesis enzymes have been shown to be regulated at the transcriptional and protein levels, the genes involved in amino acid sensing, signal transduction and regulation have not yet been identified. The overexpression of Glutamine Dumper1 leads to a large increase in the amino acid content of the plant and, as we show here, to insensitivity to externally applied amino acids. This phenotype is reminiscent of that of the pig1-1 mutant proposed to display a deregulated metabolism. These data suggest that GDU1 is involved in the regulation of amino acid metabolism and transport. As published previously, the analysis of deletion mutants proves that GDU1's VIMAG domain is important for the function of the protein. The present data show furthermore that other regions participate to this function.
Amino acid synthesis
Protein metabolism
Metabolic pathway
Amino acid metabolism
Cite
Citations (23)
The metabolism of an organism is closely related to both its internal and external environments. Metabolites can act as signal molecules that regulate the functions of genes and proteins, reflecting the status of these environments. This review discusses the metabolism and regulatory functions of O -acetylserine (OAS), S -adenosylmethionine (AdoMet), homocysteine (Hcy), and serine (Ser), which are key metabolites related to sulfur (S)-containing amino acids in plant metabolic networks, in comparison to microbial and animal metabolism. Plants are photosynthetic auxotrophs that have evolved a specific metabolic network different from those in other living organisms. Although amino acids are the building blocks of proteins and common metabolites in all living organisms, their metabolism and regulation in plants have specific features that differ from those in animals and bacteria. In plants, cysteine (Cys), an S-containing amino acid, is synthesized from sulfide and OAS derived from Ser. Methionine (Met), another S-containing amino acid, is also closely related to Ser metabolism because of its thiomethyl moiety. Its S atom is derived from Cys and its methyl group from folates, which are involved in one-carbon metabolism with Ser. One-carbon metabolism is also involved in the biosynthesis of AdoMet, which serves as a methyl donor in the methylation reactions of various biomolecules. Ser is synthesized in three pathways: the phosphorylated pathway found in all organisms and the glycolate and the glycerate pathways, which are specific to plants. Ser metabolism is not only important in Ser supply but also involved in many other functions. Among the metabolites in this network, OAS is known to function as a signal molecule to regulate the expression of OAS gene clusters in response to environmental factors. AdoMet regulates amino acid metabolism at enzymatic and translational levels and regulates gene expression as methyl donor in the DNA and histone methylation or after conversion into bioactive molecules such as polyamine and ethylene. Hcy is involved in Met–AdoMet metabolism and can regulate Ser biosynthesis at an enzymatic level. Ser metabolism is involved in development and stress responses. This review aims to summarize the metabolism and regulatory functions of OAS, AdoMet, Hcy, and Ser and compare the available knowledge for plants with that for animals and bacteria and propose a future perspective on plant research.
Amino acid synthesis
Metabolic pathway
Sulfur Metabolism
Cysteine Metabolism
Cite
Citations (46)
Darkness
Nitrogen Assimilation
Cite
Citations (8)
Serine hydroxymethyltransferase
Glyoxylic acid
Photorespiration
Cite
Citations (14)
Reverse cholesterol transport
Dietary Cholesterol
Cite
Citations (5)
Cite
Citations (9)
This chapter contains sections titled: Introduction Catecholamine Metabolism Proteinase Amino Acid and Peptide Metabolism Polyamine Metabolism Heme Metabolism Carbohydrate Metabolism Steroid Metabolism Purine Metabolism Oxygenations Pterin Metabolism Lipid Metabolism Modification of Proteins and Peptides Vitamin Metabolism Xenobiotic Metabolism Pyrimidine Metabolism Metabolism of Complex Saccharides and Glycoproteins Miscellaneous Nucleic Acid Modification and Expression Summary and Conclusions
Nucleic acid metabolism
Pyrimidine metabolism
Secondary metabolism
Carbohydrate Metabolism
Purine metabolism
Cite
Citations (1)