Pathways

Phospholipase C pathways is one of the major intracellular signalling pathways regulating hormones. It functions to activate inositol lipid signalling pathways causing the hydrolysis of PIP2 by PLC to IP3 and diacylglycerol to activate protein kinase C. IP3 releases calcium from the endoplasmic reticulum. PIP3 is an important regulator of AKT signaling and downstream pathways.

Phospholipase C pathways is one of the major intracellular signalling pathways regulating hormones. It functions to activate inositol lipid signalling pathways causing the hydrolysis of PIP2 by PLC to IP3 and diacylglycerol to activate protein kinase C. IP3 releases calcium from the endoplasmic reticulum. PIP3 is an important regulator of AKT signaling and downstream pathways.

This pathway describes the synthesis of the common phospholipids, including phosphatidylcholine, phosphatidylethanolamine, phosphatidylserine, phosphatidylinositol and cardiolipins. Phospholipid synthesis is mediated by two possible mechanisms: (1) A CDP-activated polar head group for attaches to the phosphate of phosphatidic acid or (2) A CDP-activated 1,2-diacylglycerol and an inactivated polar head group. The ER membrane is the primary site of phospholipid synthesis using precursors imported into the ER from the cytosol. To initiate the process, phosphatidic acid is generated by the linkage of two fatty acids associated with coenzyme A (CoA) carriers to glycerol-3-phosphate. This new molecule is inserted into the membrane where a phosphatase converts it into diacylglycerol or alternatively it is formed into phosphatidylinositol before the conversion. If the conversion into diacylglycerol occurs, the molecule has three possible fates depending on the type of polar head group attached: phosphatidylcholine, phosphatidylethanolamine, or phosphatidylserine. At their inception, a phospholipid is composed of a saturated fatty acid and unsaturated fatty acid on the C1 and C2 carbon of the glycerol backbone respectively. With the continuous remodelling of the phospholipid bilayer, this fatty acid distribution at these carbons changes. For example, acyl group remodelling changes the presence of acyl groups on the glycerol backbone (which were initially placed there by acyl transferases) and moves it further into the membrane as a consequence of the action of phospholipase A1 (PLA1) and phospholipase A2 (PLA2). Another modifying group that is usually added are alcohol-containing groups such as serine, ethanol amine, and choline which contain positively-charged nitrogen.

This pathway describes the synthesis of the common phospholipids, including phosphatidylcholine, phosphatidylethanolamine, phosphatidylserine, phosphatidylinositol and cardiolipins. Phospholipid synthesis is mediated by two possible mechanisms: (1) A CDP-activated polar head group for attaches to the phosphate of phosphatidic acid or (2) A CDP-activated 1,2-diacylglycerol and an inactivated polar head group. The ER membrane is the primary site of phospholipid synthesis using precursors imported into the ER from the cytosol. To initiate the process, phosphatidic acid is generated by the linkage of two fatty acids associated with coenzyme A (CoA) carriers to glycerol-3-phosphate. This new molecule is inserted into the membrane where a phosphatase converts it into diacylglycerol or alternatively it is formed into phosphatidylinositol before the conversion. If the conversion into diacylglycerol occurs, the molecule has three possible fates depending on the type of polar head group attached: phosphatidylcholine, phosphatidylethanolamine, or phosphatidylserine. At their inception, a phospholipid is composed of a saturated fatty acid and unsaturated fatty acid on the C1 and C2 carbon of the glycerol backbone respectively. With the continuous remodelling of the phospholipid bilayer, this fatty acid distribution at these carbons changes. For example, acyl group remodelling changes the presence of acyl groups on the glycerol backbone (which were initially placed there by acyl transferases) and moves it further into the membrane as a consequence of the action of phospholipase A1 (PLA1) and phospholipase A2 (PLA2). Another modifying group that is usually added are alcohol-containing groups such as serine, ethanol amine, and choline which contain positively-charged nitrogen.

This pathway describes the synthesis of the common phospholipids, including phosphatidylcholine, phosphatidylethanolamine, phosphatidylserine, phosphatidylinositol and cardiolipins. Phospholipid synthesis is mediated by two possible mechanisms: (1) A CDP-activated polar head group for attaches to the phosphate of phosphatidic acid or (2) A CDP-activated 1,2-diacylglycerol and an inactivated polar head group. The ER membrane is the primary site of phospholipid synthesis using precursors imported into the ER from the cytosol. To initiate the process, phosphatidic acid is generated by the linkage of two fatty acids associated with coenzyme A (CoA) carriers to glycerol-3-phosphate. This new molecule is inserted into the membrane where a phosphatase converts it into diacylglycerol or alternatively it is formed into phosphatidylinositol before the conversion. If the conversion into diacylglycerol occurs, the molecule has three possible fates depending on the type of polar head group attached: phosphatidylcholine, phosphatidylethanolamine, or phosphatidylserine. At their inception, a phospholipid is composed of a saturated fatty acid and unsaturated fatty acid on the C1 and C2 carbon of the glycerol backbone respectively. With the continuous remodelling of the phospholipid bilayer, this fatty acid distribution at these carbons changes. For example, acyl group remodelling changes the presence of acyl groups on the glycerol backbone (which were initially placed there by acyl transferases) and moves it further into the membrane as a consequence of the action of phospholipase A1 (PLA1) and phospholipase A2 (PLA2). Another modifying group that is usually added are alcohol-containing groups such as serine, ethanol amine, and choline which contain positively-charged nitrogen.

This pathway describes the synthesis of the common phospholipids, including phosphatidylcholine, phosphatidylethanolamine, phosphatidylserine, phosphatidylinositol and cardiolipins. Phospholipid synthesis is mediated by two possible mechanisms: (1) A CDP-activated polar head group for attaches to the phosphate of phosphatidic acid or (2) A CDP-activated 1,2-diacylglycerol and an inactivated polar head group. The ER membrane is the primary site of phospholipid synthesis using precursors imported into the ER from the cytosol. To initiate the process, phosphatidic acid is generated by the linkage of two fatty acids associated with coenzyme A (CoA) carriers to glycerol-3-phosphate. This new molecule is inserted into the membrane where a phosphatase converts it into diacylglycerol or alternatively it is formed into phosphatidylinositol before the conversion. If the conversion into diacylglycerol occurs, the molecule has three possible fates depending on the type of polar head group attached: phosphatidylcholine, phosphatidylethanolamine, or phosphatidylserine. At their inception, a phospholipid is composed of a saturated fatty acid and unsaturated fatty acid on the C1 and C2 carbon of the glycerol backbone respectively. With the continuous remodelling of the phospholipid bilayer, this fatty acid distribution at these carbons changes. For example, acyl group remodelling changes the presence of acyl groups on the glycerol backbone (which were initially placed there by acyl transferases) and moves it further into the membrane as a consequence of the action of phospholipase A1 (PLA1) and phospholipase A2 (PLA2). Another modifying group that is usually added are alcohol-containing groups such as serine, ethanol amine, and choline which contain positively-charged nitrogen.

This pathway describes the synthesis of the common phospholipids, including phosphatidylcholine, phosphatidylethanolamine, phosphatidylserine, phosphatidylinositol and cardiolipins. Phospholipid synthesis is mediated by two possible mechanisms: (1) A CDP-activated polar head group for attaches to the phosphate of phosphatidic acid or (2) A CDP-activated 1,2-diacylglycerol and an inactivated polar head group. The ER membrane is the primary site of phospholipid synthesis using precursors imported into the ER from the cytosol. To initiate the process, phosphatidic acid is generated by the linkage of two fatty acids associated with coenzyme A (CoA) carriers to glycerol-3-phosphate. This new molecule is inserted into the membrane where a phosphatase converts it into diacylglycerol or alternatively it is formed into phosphatidylinositol before the conversion. If the conversion into diacylglycerol occurs, the molecule has three possible fates depending on the type of polar head group attached: phosphatidylcholine, phosphatidylethanolamine, or phosphatidylserine. At their inception, a phospholipid is composed of a saturated fatty acid and unsaturated fatty acid on the C1 and C2 carbon of the glycerol backbone respectively. With the continuous remodelling of the phospholipid bilayer, this fatty acid distribution at these carbons changes. For example, acyl group remodelling changes the presence of acyl groups on the glycerol backbone (which were initially placed there by acyl transferases) and moves it further into the membrane as a consequence of the action of phospholipase A1 (PLA1) and phospholipase A2 (PLA2). Another modifying group that is usually added are alcohol-containing groups such as serine, ethanol amine, and choline which contain positively-charged nitrogen.

Phospholipids are membrane components in P. aeruginosa. All phospholipids contain sn-glycerol-3-phosphate esterified with fatty acids at the sn-1 and sn-2 positions. The reaction starts from a glycerone phosphate (dihydroxyacetone phosphate) produced in glycolysis. The glycerone phosphate is transformed into an sn-glycerol 3-phosphate (glycerol 3 phosphate) by NADPH-driven glycerol-3-phosphate dehydrogenase. sn-Glycerol 3-phosphate is transformed to a 1-acyl-sn-glycerol 3-phosphate (lysophosphatidic acid). This can be achieved by an sn-glycerol-3-phosphate acyltransferase that interacts either with a long-chain acyl-CoA or with an acyl-[acp]. The 1-acyl-sn-glycerol 3-phosphate is transformed into a 1,2-diacyl-sn-glycerol 3-phosphate (phosphatidic acid) through a 1-acylglycerol-3-phosphate O-acyltransferase. This compound is then converted into a CPD-diacylglycerol through a CTP phosphatidate cytididyltransferase. CPD-diacylglycerol can be transformed either into an L-1-phosphatidylserine or an L-1-phosphatidylglycerol-phosphate through a phosphatidylserine synthase or a phosphatidylglycerophosphate synthase, respectively. The L-1-phosphatidylserine transforms into L-1-phosphatidylethanolamine through a phosphatidylserine decarboxylase. On the other hand, L-1-phosphatidylglycerol-phosphate gets transformed into an L-1-phosphatidyl-glycerol through a phosphatidylglycerophosphatase. These 2 products combine to produce a cardiolipin and an ethanolamine. The L-1 phosphatidyl-glycerol can also interact with cardiolipin synthase resulting in a glycerol and a cardiolipin.

Phospholipids are membrane components in E. coli. The major phospholipids of E. coli are phosphatidylethanolamine, phosphatidylglycerol, and cardiolipin. All phospholipids contain sn-glycerol-3-phosphate esterified with fatty acids at the sn-1 and sn-2 positions. The reaction starts from a glycerone phosphate (dihydroxyacetone phosphate) produced in glycolysis. The glycerone phosphate is transformed into an sn-glycerol 3-phosphate (glycerol 3 phosphate) by NADPH-driven glycerol-3-phosphate dehydrogenase. sn-Glycerol 3-phosphate is transformed to a 1-acyl-sn-glycerol 3-phosphate (lysophosphatidic acid). This can be achieved by an sn-glycerol-3-phosphate acyltransferase that interacts either with a long-chain acyl-CoA or with an acyl-[acp]. The 1-acyl-sn-glycerol 3-phosphate is transformed into a 1,2-diacyl-sn-glycerol 3-phosphate (phosphatidic acid) through a 1-acylglycerol-3-phosphate O-acyltransferase. This compound is then converted into a CPD-diacylglycerol through a CTP phosphatidate cytididyltransferase. CPD-diacylglycerol can be transformed either into an L-1-phosphatidylserine or an L-1-phosphatidylglycerol-phosphate through a phosphatidylserine synthase or a phosphatidylglycerophosphate synthase, respectively. The L-1-phosphatidylserine transforms into L-1-phosphatidylethanolamine through a phosphatidylserine decarboxylase. On the other hand, L-1-phosphatidylglycerol-phosphate gets transformed into an L-1-phosphatidyl-glycerol through a phosphatidylglycerophosphatase. These 2 products combine to produce a cardiolipin and an ethanolamine. The L-1 phosphatidyl-glycerol can also interact with cardiolipin synthase resulting in a glycerol and a cardiolipin.