Rapid transbilayer movement of fluorescent phospholipid analogues in the plasma membrane of endocytosis-deficient yeast cells does not require the Drs2 protein

Uwe Marx, Thomas Polakowski, Thomas Pomorski, Christine Lang, Hannah Nelson, Nathan Nelson, Andreas Herrmann

Research output: Contribution to journalArticlepeer-review

Abstract

Evidence is presented that endocytosis-deficient Saccharomyces cerevisiae end4 yeast cells rapidly internalize the fluorescent phospholipid analogues 1-palmitoyl-2-{6-[7-nitro-2,1,3-benzoxadiazol-4-yl(NBD)amino] caproyl)phosphatidylcholine (P-C6-NBD-PtdCho) and P-C6-NBD-phosphatidylserine (P-C6-NBD-PtdSer). Both analogues redistributed between the exoplasmic and cytoplasmic leaflet with a half-time of < 15 min at 0 °C. The plateau of internalized analogues was about 70%. Transbilayer movement is probably protein-mediated, as the flip-flop of both analogues was very slow in liposomes composed of plasma-membrane lipids. Rapid analogue internalization was not abolished on depletion of intracellular ATP by about 90%. For P-C6- NBD-PtdCho only was a moderate decrease in the plateau of internalized analogues of about 20% observed, while that of P-C6-NBD-PtdSer was not affected. The Drs2 protein plays only a minor role, if any, in the rapid transbilayer movement of analogues in S. cerevisiae end4 cells. In S. cerevisiae end4 Δdrs2 cells harbouring both an end4 allele and a drs2 null allele, about 60% and 50% of P-C6-NBD-PtdCho and P-C6-NBDPtdSer, respectively, became internalized within 15 min at 0 °C. The preferential orientation of P-C6-NBDPtdSer to the cytoplasmic leaflet is in qualitative agreement with the sequestering of endogenous phosphatidylserine to the cytoplasmic leaflet, as assessed by binding of annexin V. Virtually no binding of annexin V to spheroplasts of the parent wild-type strain or the mutant strains was observed. Likewise, no difference in the exposure of endogenous aminophospholipids to the exoplasmic leaflet between these strains was found by labelling with trinitrobenzenesulfonic acid. Thus, lipid asymmetry, at least of aminophospholipids, was preserved in S. cerevisiae end4 cells independently of the presence of the Drs2 protein.

Original languageEnglish
Pages (from-to)254-264
Number of pages11
JournalEuropean Journal of Biochemistry
Volume263
Issue number1
DOIs
StatePublished - 1 Jul 1999

Keywords

  • Lipids
  • Plasma membrane
  • Transbilayer movement
  • Translocase
  • Yeast

Fingerprint

Dive into the research topics of 'Rapid transbilayer movement of fluorescent phospholipid analogues in the plasma membrane of endocytosis-deficient yeast cells does not require the Drs2 protein'. Together they form a unique fingerprint.

Cite this