ISSN:
0173-0835
Keywords:
Free-flow electrophoresis
;
Hepatocytes
;
Endosomes
;
Secretory component
;
Asialoglycoprotein
;
Chemistry
;
Biochemistry and Biotechnology
Source:
Wiley InterScience Backfile Collection 1832-2000
Topics:
Biology
,
Chemistry and Pharmacology
Notes:
The separation of functional early and late endosomes from other cellular compartments by free-flow electrophoresis (FFE) has been previously demonstrated in nonpolarized cells [1, 2]. Here, using 125I-labeled anti-secretory component antibodies ([125I]SC Ab) and FITC-labeled asialoorosomucoid (FITC-ASOR) as markers of the transcytotic and lysosomal pathway, respectively, we demonstrate the separation of three distinct endosome subpopulations from polarized rat hepatocytes. Internalization of both markers at 16°C resulted in their accumulation in a common endosome compartment, indicating that both the transcytotic and the lysosomal pathways are arrested in the sorting early endosome at temperatures below 20°C. After chase of the markers from early endosomes into the transcytotic or the degradative route at 37°C, transcytotic endosomes carrying [125I]SC Ab migrated with an electrophoretic motility between early and late endosomes while late endosomes labeled with FITC-ASOR were deflected more towards the anode than early endosomes. These data indicate that in rat hepatocytes, the transcytotic and lysosomal pathways utilize a common (i.e. early endosomes) and two distinct endosome subpopulations (i.e. transcytotic endosomes, late endosomes) prior to delivering proteins for biliary secretion or lysosomal degradation, respectively.
Additional Material:
4 Ill.
Type of Medium:
Electronic Resource
URL:
http://dx.doi.org/10.1002/elps.1150181405
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