Regulation of lipoprotein lipase synthesis in 3T3-L1 adipocytes by cachectin. Further proof for identity with tumour necrosis factor.
We investigated the mechanism by which the endotoxin-induced macrophage secretory protein cachectin is able to suppress the activity of lipoprotein lipase in 3T3-L1 adipocytes. The loss in activity results from an effect on the synthesis of the enzyme, as determined by a decreased incorporation of [35S]methionine into immunoprecipitable lipoprotein lipase. The results were nearly identical whether crude conditioned medium or a highly purified preparation was utilized as a source of cachectin. [35S]Methionine incorporation into acid-precipitable protein was minimally affected by purified cachectin, suggesting that the suppression of the lipoprotein lipase was not due to a general suppression of protein synthesis. These results, taken together with our previous work, provide additional evidence that cachectin and tumour necrosis factor are functionally identical.
D000273:Adipose Tissue / Q000201:enzymology*; D002460:Cell Line; D006023:Glycoproteins / Q000494:pharmacology*; D008071:Lipoprotein Lipase / Q000037:antagonists & inhibitors / Q000096:biosynthesis*; D008715:Methionine / Q000378:metabolism; D014409:Tumor Necrosis Factor-alpha
D006023:Glycoproteins; D014409:Tumor Necrosis Factor-alpha; D008715:Methionine; D008071:Lipoprotein Lipase