Abstract
The internalization of fluorescent phospholipid analogs of phosphatidylcholine (PC), phosphatidylethanolamine (PE), phosphatidylserine (PS), and sphingomyelin (SM) in Leishmania infantum promastigotes was studied. We observed a rapid inward redistribution of NBD-PC, -PE, and -PS across the plasma membrane at 28 and 4 degrees C. This internalization was shown to be independent of the endocytic activity of parasites. Rapid inward movement was coupled to an energy-dependent transporter because it was almost inhibited by depletion of cellular ATP and was blocked after pretreatment with N-ethylmaleimide (NEM). In contrast, NBD-SM traverses the plasma membrane by passive flip-flop. By comparing this pattern of phospholipid transbilayer movement with those known from other eukaryotic cells, candidate lipid transporters are discussed.
Publication types
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Research Support, Non-U.S. Gov't
MeSH terms
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4-Chloro-7-nitrobenzofurazan / analogs & derivatives*
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4-Chloro-7-nitrobenzofurazan / metabolism
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Adenosine Triphosphate / metabolism
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Animals
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Biological Transport, Active
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Cell Membrane / metabolism
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Energy Metabolism
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Fluorescent Dyes
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Leishmania infantum / metabolism*
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Phosphatidylcholines / metabolism
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Phosphatidylethanolamines / metabolism
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Phosphatidylserines / metabolism
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Phospholipids / metabolism*
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Sphingomyelins / metabolism
Substances
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1-acyl-2-(12-((7-nitrobenz-2-oxa-1,3-diazol-4-yl)amino)dodecanoyl)phosphatidylcholine
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Fluorescent Dyes
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N-(7-nitro-2,1,3-benzoxadiazol-4-yl)phosphatidylserine
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N-4-nitrobenzo-2-oxa-1,3-diazoleaminocaproyl sphingosylphosphorylcholine
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Phosphatidylcholines
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Phosphatidylethanolamines
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Phosphatidylserines
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Phospholipids
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Sphingomyelins
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N-(7-nitrobenz-2-oxa-1,3-diazol-4-yl)phosphatidylethanolamine
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Adenosine Triphosphate
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4-Chloro-7-nitrobenzofurazan