Combined Omics Approach Identifies Gambogic Acid and Related Xanthones as Covalent Inhibitors of the Serine Palmitoyltransferase Complex.
In this study, we identify the natural product gambogic acid as well as structurally related synthetic xanthones as first-in-class covalent inhibitors of the de novo sphingolipid biosynthesis. We apply chemoproteomics to determine that gambogic acid binds to the regulatory small subunit B of the serine palmitoyltransferase complex (SPTSSB). We then test structurally related synthetic xanthones to identify 18 as an equally potent but more selective binder of SPTSSB and show that 18 reduces sphingolipid levels in situ and in vivo. Finally, using various biological methods, we demonstrate that 18 induces cellular responses characteristic for diminished sphingosine-1-phosphate (S1P) signaling. This study demonstrates that SPTSSB may become a viable therapeutic target in various diseases with pathological S1P signaling. Furthermore, we believe that our compound will become a valuable tool for studying the sphingolipid metabolism and serve as a blueprint for the development of a new generation of sphingolipid biosynthesis inhibitors.
['Hoch|Dominic G|DG|', 'Abegg|Daniel|D|', 'Hannich|J Thomas|JT|', 'Pechalrieu|Dany|D|', 'Shuster|Anton|A|', 'Dwyer|Brendan G|BG|', 'Wang|Chao|C|', 'Zhang|Xiaojin|X|', 'You|Qidong|Q|', 'Riezman|Howard|H|', 'Adibekian|Alexander|A|']
D000818:Animals D055808:Drug Discovery D004791:Enzyme Inhibitors D057809:HEK293 Cells D006801:Humans D008246:Lysophospholipids D061986:MCF-7 Cells D051379:Mice D008813:Mice, Inbred ICR D040901:Proteomics D051102:Serine C-Palmitoyltransferase D013107:Sphingolipids D013110:Sphingosine D044004:Xanthones
natural products sphingosine-1-phosphate chemical proteomics mass spectrometry target identification