Sphingolipids signal heat stress-induced ubiquitin-dependent proteolysis.

Published

Journal Article

Sphingolipids are essential eukaryotic membrane lipids that are structurally and metabolically conserved through evolution. Sphingolipids have also been proposed to regulate eukaryotic stress responses as novel second messengers. Here we show that, in Saccharomyces cerevisiae, phytosphingosine, a putative sphingolipid second messenger, mediates heat stress signaling and activates ubiquitin-dependent proteolysis via the endocytosis vacuolar degradation and 26 S proteasome pathways. Inactivation of serine palmitoyltransferase, a key enzyme in generating endogenous phytosphingosine, prevents proteolysis during heat stress. Addition of phytosphingosine bypasses the requirement for serine palmitoyltransferase and restores proteolysis. Phytosphingosine-induced proteolysis requires multiubiquitin chain formation through the stress-responsive lysine 63 residue of ubiquitin. We propose that heat stress increases phytosphingosine and activates ubiquitin-dependent proteolysis.

Full Text

Duke Authors

Cited Authors

  • Chung, N; Jenkins, G; Hannun, YA; Heitman, J; Obeid, LM

Published Date

  • June 9, 2000

Published In

Volume / Issue

  • 275 / 23

Start / End Page

  • 17229 - 17232

PubMed ID

  • 10764732

Pubmed Central ID

  • 10764732

International Standard Serial Number (ISSN)

  • 0021-9258

Digital Object Identifier (DOI)

  • 10.1074/jbc.C000229200

Language

  • eng

Conference Location

  • United States