title: Protein-sphingolipid interactions within cellular membranes.
abstract: Each intracellular organelle critically depends on maintaining its specific lipid composition that in turn contributes to the biophysical properties of the membrane. With our knowledge increasing about the organization of membranes with defined microdomains of different lipid compositions, questions arise regarding the molecular mechanisms that underlie the targeting to/segregation from microdomains of a given protein. In addition to specific lipid-transmembrane segment interactions as a basis for partitioning, the presence in a given microdomain may alter the conformation of proteins and, thus, the activity and availability for regulatory modifications. However, for most proteins, the specific lipid environment of transmembrane segments as well as its relevance to protein function and overall membrane organization are largely unknown. To help fill this gap, we have synthesized a novel photoactive sphingolipid precursor that, together with a precursor for phosphoglycerolipids and with photo-cholesterol, was investigated in vivo with regard to specific protein transmembrane span-lipid interactions. As a proof of principle, we show specific labeling of the ceramide transporter with the sphingolipid probe and describe specific in vivo interactions of lipids with caveolin-1, phosphatidylinositol transfer protein beta, and the mature form of nicastrin. This novel photolabile sphingolipid probe allows the detection of protein-sphingolipid interactions within the membrane bilayer of living cells.
authors: Heidelberg University Biochemistry Center, 69120 Heidelberg, Germany.
authors: Per
authors: P
authors: Haberkant
authors: Oliver
authors: O
authors: Schmitt
authors: F-Xabier
authors: FX
authors: Contreras
authors: Christoph
authors: C
authors: Thiele
authors: Kentaro
authors: K
authors: Hanada
authors: Hein
authors: H
authors: Sprong
authors: Constanze
authors: C
authors: Reinhard
authors: Felix T
authors: FT
authors: Wieland
authors: Britta
authors: B
authors: Brügger
mesh_terms: D053829:Amyloid Precursor Protein Secretases / Q000378:metabolism*; D000818:Animals; D051242:Caveolin 1 / Q000378:metabolism*; D002460:Cell Line; D002462:Cell Membrane / Q000378:metabolism*; D006224:Cricetinae; D008562:Membrane Glycoproteins / Q000378:metabolism*; D015336:Molecular Probe Techniques; D049294:Phospholipid Transfer Proteins / Q000378:metabolism*; D011506:Proteins / Q000378:metabolism*; D013107:Sphingolipids / Q000378:metabolism*
chemical_list: D051242:Caveolin 1; D008562:Membrane Glycoproteins; D049294:Phospholipid Transfer Proteins; D011506:Proteins; D013107:Sphingolipids; C413604:nicastrin protein; D053829:Amyloid Precursor Protein Secretases