ISSN:
1615-6102
Keywords:
Lipid pathways
;
Fluorescent analogues
;
Lysosomes
;
Golgi apparatus
;
Amoeba proteus
Source:
Springer Online Journal Archives 1860-2000
Topics:
Biology
Notes:
Summary The uptake and intracellular transport of 5 different lipid analogues derived from phosphatidylethanolamine, phosphatidylcholine, sphingomyelin, ceramide, and cholesterol have been studied in livingAmoeba proteus using fluorescence microscopy. Phosphatidylcholine and sphingomyelin are predominantly transported from the external environment to the cell interior in a manner consistent with induced macropinocytosis. On the other hand, phosphatidylethanolamine, ceramide, and cholesterol mainly enter the cellular matrix by carrier-mediated, ATP-dependent transmembrane transport. In general, all lipid analogues are first imported to a large pool of endosomal or lysosomal vacuoles, and then partitioned to numerous tiny cisternal elements; only sphingomyelin remains in the lysosomes and is not exported to other membrane compartments. The ultrastructural localization of ceramide indicates that the cisternal elements result from the decay of the Golgi apparatus into single cisternae during lipid accumulation. As a whole, the transport pathway of lipid analogues inA. proteus from the cell surface to different cell organelles shows many similarities to respective processes in a variety of metazoan cells.
Type of Medium:
Electronic Resource
URL:
http://dx.doi.org/10.1007/BF01276638
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