Sphingomyelin pathway

Relation of phosphatidylcholine synthesis with the sphingomyelin pathway... 

Kolesnick, R. and Golde, D.W. The sphingomyelin pathway in tumor necrosis factor and interleukin-1 signaling (1994) Cell 77, 325-328... 

R. Kolesnick, and D. W. Golde, The Sphingomyelin Pathway in Tumor Necrosis Factor and Interleukin-1 Signaling, Cell, 77 (1994) 325-328. 

Ito Y, Sato S, Ohashi T et al (2004) Reduction of airway anion secretion via CFTR in sphingomyelin pathway. Biochem Biophys Res Commnn 324(2) 901-908... 

Kolesnick, R. (2002). The therapeutic potential of modulating the ceramide/sphingomyelin pathway. J Clin Invest 110, 3-8. 

Figure 1. Pathways for the synthesis of phosphatidylcholine, phosphatidylethanolamine and sphingomyelin. Abbreviations CK, choline kinase CPT, cholinephosphotransferase CT, CTP phosphooholine cytidylyltransferase DAG, diacylglycerol PC, phosphatidylcholine PE, phosphatidylethanolamine PEMT, phosphatidylethanolamine-N-methyltransferase SM, sphingomyelin SMase, sphingomyelinase SMsyn, sphingomyelin synthase.

Activation of the sphingomyelin signaling pathway in intact EL4 cells and in a cell-free system by lL-1 beta. Science 259 519-522... 

P., 1996, Opposite effects of tumor necrosis factor a on the sphingomyehn-ceramide pathway in two myeloid leukemia ceU hues Role of transverse sphingomyelin distribution in the plasma membrane. Blood 88 1465-1472. 

Fig. 6.12. Formation and function of the messenger substance ceramide. The starting point for the synthesis of ceramide is sphingomyelin, which is converted to phosphocholine and ceramide by the action of a sphingomyelinase. Sphingomyelinase is activated via a pathway starting from tumor necrosis factor a (TNFa) and its receptor. Ceramide serves as an activator of protein kinases and protein phosphatases. RI fatty add side chain.

Cholesterol is an important structural component of cellular membranes, where it plays a role in modulating membrane fluidity and phase transitions, and, together with sphingomyelin, forms lipid rafts or caveolae, which are sites where proteins involved in diverse signaling pathways become concentrated. Furthermore, cholesterol is a precursor of oxysterols, steroid hormones, and bile acids. 

FIGURE 1 Pathways for the breakdown of GM1, globoside, and sphingomyelin to ceramide. A defect in the enzyme hydrolyzing a particular step is indicated by and the disease that results from accumulation of the partial breakdown product is noted. 

The pathways to sphingomyelin and glycosphingolipids. Figure 19.13 elaborates on some pathways from ceramide to glycosphingolipids. 

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