Ca2+ redistribution from bound to free form is required for tumor necrosis factor actions in 30A5 preadipocytes.
Tumor necrosis factor/cachectin (TNF) inhibits differentiation of 30A5 preadipocytes into adipocytes. In this process, TNF inhibits the expression of the gene for acetyl-coenzyme-A carboxylase, the rate-limiting enzyme for biogenesis of long chain fatty acids. One of the early reactions caused by TNF is the Ca2+ redistribution of Ca2+ from the bound form to the free form. This Ca2+ redistribution results in a transient Ca2+ efflux. High concentrations of Mg2+ inhibit Ca2+ redistribution and efflux. This inhibition reverses the repression of acetyl-coenzyme-A carboxylase and reverses the TNF inhibition of the differentiation of 30A5 preadipocytes into adipocytes. This indicates that Ca2+ redistribution between the bound and the free form is an obligatory event in the sequence of actions caused by TNF in 30A5 cells.
Lee
K H
KH
Department of Biochemistry, Purdue University, West Lafayette, Indiana 47907.
White
K J
KJ
Robinson
J P
JP
Kim
K H
KH
D000103:Acetyl-CoA Carboxylase / Q000037:antagonists & inhibitors*; D000273:Adipose Tissue / Q000166:cytology / Q000187:drug effects / Q000378:metabolism*; D000818:Animals; D000001:Calcimycin / Q000494:pharmacology; D002118:Calcium / Q000378:metabolism*; D002454:Cell Differentiation / Q000187:drug effects; D002478:Cells, Cultured; D008274:Magnesium / Q000494:pharmacology; D014409:Tumor Necrosis Factor-alpha / Q000494:pharmacology*; D010566:Virulence Factors, Bordetella / Q000494:pharmacology
D014409:Tumor Necrosis Factor-alpha; D010566:Virulence Factors, Bordetella; D000001:Calcimycin; D000103:Acetyl-CoA Carboxylase; D008274:Magnesium; D002118:Calcium