Ulrike Seifert

Universitätsklinikum Schleswig - Holstein, Kiel, Schleswig-Holstein, Germany

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Publications (1)2.3 Total impact

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    ABSTRACT: Tumor necrosis factor (TNF) contributes to insulin resistance by binding to the 55kDa TNF receptor (TNF-R55), resulting in serine phosphorylation of proteins such as insulin receptor (IR) substrate (IRS)-1, followed by reduced tyrosine phosphorylation of IRS-1 through the IR and, thereby, diminished IR signal transduction. Through independent receptor domains, TNF-R55 activates a neutral (N-SMase) and an acid sphingomyelinase (A-SMase), that both generate the sphingolipid ceramide. Multiple candidate kinases have been identified that serine-phosphorylate IRS-1 in response to TNF or ceramide. However, due to the fact that the receptor domain of TNF-R55 mediating inhibition of the IR has not been mapped, it is currently unknown whether TNF exerts these effects with participation of N-SMase or A-SMase. Here, we identify the death domain of TNF-R55 as responsible for the inhibitory effects of TNF on tyrosine phosphorylation of IRS-1, implicating ceramide generated by A-SMase as a downstream mediator of inhibition of IR signaling.
    No preview · Article · May 2005 · Biochemical and Biophysical Research Communications

Publication Stats

19 Citations
2.30 Total Impact Points


  • 2005
    • Universitätsklinikum Schleswig - Holstein
      • Institut für Immunologie (Kiel)
      Kiel, Schleswig-Holstein, Germany