Browsing Pathways

Thioredoxins are a class of proteins that are used in redox reactions, and are found in all living organisms. In humans, they respond to reactive oxygen species, while in plants they are important for growth, photosynthesis, flowering and seed formation. In E. coli, thioredoxins catalyze a number of redox reactions, and are important in stress response, as well as other functions. In this pathway, oxidized thioredoxin is reduced by thioredoxin reductase, in order to form reduced thioredoxin. This reaction also uses NADPH as a cofactor. Reduced thioredoxin then, as part of a redox reaction, acts as the oxidizing agent and converts an oxidized electron acceptor into a reduced electron acceptor. This then produces oxidized thioredoxin, which can be further reduced and reused in other redox reactions.

Thioredoxins are a class of proteins that are used in redox reactions, and are found in all living organisms. In humans, they respond to reactive oxygen species, while in plants they are important for growth, photosynthesis, flowering and seed formation. In E. coli, thioredoxins catalyze a number of redox reactions, and are important in stress response, as well as other functions. In this pathway, oxidized thioredoxin is reduced by thioredoxin reductase, in order to form reduced thioredoxin. This reaction also uses NADPH as a cofactor. Reduced thioredoxin then, as part of a redox reaction, acts as the oxidizing agent and converts an oxidized electron acceptor into a reduced electron acceptor. This then produces oxidized thioredoxin, which can be further reduced and reused in other redox reactions.

Cardiolipin (CL) is an important component of the inner mitochondrial membrane where it constitutes about 20% of the total lipid composition. It is essential for the optimal function of numerous enzymes that are involved in mitochondrial energy metabolism (Wikipedia). Cardiolipin biosynthesis occurs mainly in the mitochondria, but there also exists an alternative synthesis route for CDP-diacylglycerol that takes place in the endoplasmic reticulum. This second route may supplement this pathway. All membrane-localized enzymes are coloured dark green in the image. First, dihydroxyacetone phosphate (or glycerone phosphate) from glycolysis is used by the cytosolic enzyme glycerol-3-phosphate dehydrogenase [NAD(+)] to synthesize sn-glycerol 3-phosphate. Second, the mitochondrial outer membrane enzyme glycerol-3-phosphate acyltransferase esterifies an acyl-group to the sn-1 position of sn-glycerol 3-phosphate to form 1-acyl-sn-glycerol 3-phosphate (lysophosphatidic acid or LPA). Third, the enzyme 1-acyl-sn-glycerol-3-phosphate acyltransferase converts LPA into phosphatidic acid (PA or 1,2-diacyl-sn-glycerol 3-phosphate) by esterifying an acyl-group to the sn-2 position of the glycerol backbone. PA is then transferred to the inner mitochondrial membrane to continue cardiolipin synthesis. Fourth, magnesium-dependent phosphatidate cytidylyltransferase catalyzes the conversion of PA into CDP-diacylglycerol. Fifth, CDP-diacylglycerol--glycerol-3-phosphate 3-phosphatidyltransferase synthesizes phosphatidylglycerophosphate (PGP). Sixth, phosphatidylglycerophosphatase and protein-tyrosine phosphatase dephosphorylates PGP to form phosphatidylglycerol (PG). Last, cardiolipin synthase catalyzes the synthesis of cardiolipin by transferring a phosphatidyl group from a second CDP-diacylglycerol to PG. It requires a divalent metal cation cofactor.

Cardiolipin (CL) is an important component of the inner mitochondrial membrane where it constitutes about 20% of the total lipid composition. It is essential for the optimal function of numerous enzymes that are involved in mitochondrial energy metabolism (Wikipedia). Cardiolipin biosynthesis occurs mainly in the mitochondria, but there also exists an alternative synthesis route for CDP-diacylglycerol that takes place in the endoplasmic reticulum. This second route may supplement this pathway. All membrane-localized enzymes are coloured dark green in the image. First, dihydroxyacetone phosphate (or glycerone phosphate) from glycolysis is used by the cytosolic enzyme glycerol-3-phosphate dehydrogenase [NAD(+)] to synthesize sn-glycerol 3-phosphate. Second, the mitochondrial outer membrane enzyme glycerol-3-phosphate acyltransferase esterifies an acyl-group to the sn-1 position of sn-glycerol 3-phosphate to form 1-acyl-sn-glycerol 3-phosphate (lysophosphatidic acid or LPA). Third, the enzyme 1-acyl-sn-glycerol-3-phosphate acyltransferase converts LPA into phosphatidic acid (PA or 1,2-diacyl-sn-glycerol 3-phosphate) by esterifying an acyl-group to the sn-2 position of the glycerol backbone. PA is then transferred to the inner mitochondrial membrane to continue cardiolipin synthesis. Fourth, magnesium-dependent phosphatidate cytidylyltransferase catalyzes the conversion of PA into CDP-diacylglycerol. Fifth, CDP-diacylglycerol--glycerol-3-phosphate 3-phosphatidyltransferase synthesizes phosphatidylglycerophosphate (PGP). Sixth, phosphatidylglycerophosphatase and protein-tyrosine phosphatase dephosphorylates PGP to form phosphatidylglycerol (PG). Last, cardiolipin synthase catalyzes the synthesis of cardiolipin by transferring a phosphatidyl group from a second CDP-diacylglycerol to PG. It requires a divalent metal cation cofactor.

Thioredoxins are a class of proteins that are used in redox reactions, and are found in all living organisms. In humans, they respond to reactive oxygen species, while in plants they are important for growth, photosynthesis, flowering and seed formation. In E. coli, thioredoxins catalyze a number of redox reactions, and are important in stress response, as well as other functions. In this pathway, oxidized thioredoxin is reduced by thioredoxin reductase, in order to form reduced thioredoxin. This reaction also uses NADPH as a cofactor. Reduced thioredoxin then, as part of a redox reaction, acts as the oxidizing agent and converts an oxidized electron acceptor into a reduced electron acceptor. This then produces oxidized thioredoxin, which can be further reduced and reused in other redox reactions.

Thioredoxins are a class of proteins that are used in redox reactions, and are found in all living organisms. In humans, they respond to reactive oxygen species, while in plants they are important for growth, photosynthesis, flowering and seed formation. In E. coli, thioredoxins catalyze a number of redox reactions, and are important in stress response, as well as other functions. In this pathway, oxidized thioredoxin is reduced by thioredoxin reductase, in order to form reduced thioredoxin. This reaction also uses NADPH as a cofactor. Reduced thioredoxin then, as part of a redox reaction, acts as the oxidizing agent and converts an oxidized electron acceptor into a reduced electron acceptor. This then produces oxidized thioredoxin, which can be further reduced and reused in other redox reactions.

Thioredoxins are a class of proteins that are used in redox reactions, and are found in all living organisms. In humans, they respond to reactive oxygen species, while in plants they are important for growth, photosynthesis, flowering and seed formation. In E. coli, thioredoxins catalyze a number of redox reactions, and are important in stress response, as well as other functions. In this pathway, oxidized thioredoxin is reduced by thioredoxin reductase, in order to form reduced thioredoxin. This reaction also uses NADPH as a cofactor. Reduced thioredoxin then, as part of a redox reaction, acts as the oxidizing agent and converts an oxidized electron acceptor into a reduced electron acceptor. This then produces oxidized thioredoxin, which can be further reduced and reused in other redox reactions.

Thioredoxins are a class of proteins that are used in redox reactions, and are found in all living organisms. In humans, they respond to reactive oxygen species, while in plants they are important for growth, photosynthesis, flowering and seed formation. In E. coli, thioredoxins catalyze a number of redox reactions, and are important in stress response, as well as other functions. In this pathway, oxidized thioredoxin is reduced by thioredoxin reductase, in order to form reduced thioredoxin. This reaction also uses NADPH as a cofactor. Reduced thioredoxin then, as part of a redox reaction, acts as the oxidizing agent and converts an oxidized electron acceptor into a reduced electron acceptor. This then produces oxidized thioredoxin, which can be further reduced and reused in other redox reactions.

Thioredoxins are a class of proteins that are used in redox reactions, and are found in all living organisms. In humans, they respond to reactive oxygen species, while in plants they are important for growth, photosynthesis, flowering and seed formation. In E. coli, thioredoxins catalyze a number of redox reactions, and are important in stress response, as well as other functions. In this pathway, oxidized thioredoxin is reduced by thioredoxin reductase, in order to form reduced thioredoxin. This reaction also uses NADPH as a cofactor. Reduced thioredoxin then, as part of a redox reaction, acts as the oxidizing agent and converts an oxidized electron acceptor into a reduced electron acceptor. This then produces oxidized thioredoxin, which can be further reduced and reused in other redox reactions.

Thioredoxins are a class of proteins that are used in redox reactions, and are found in all living organisms. In humans, they respond to reactive oxygen species, while in plants they are important for growth, photosynthesis, flowering and seed formation. In E. coli, thioredoxins catalyze a number of redox reactions, and are important in stress response, as well as other functions. In this pathway, oxidized thioredoxin is reduced by thioredoxin reductase, in order to form reduced thioredoxin. This reaction also uses NADPH as a cofactor. Reduced thioredoxin then, as part of a redox reaction, acts as the oxidizing agent and converts an oxidized electron acceptor into a reduced electron acceptor. This then produces oxidized thioredoxin, which can be further reduced and reused in other redox reactions.