Quantification of polarized trafficking of transferrin and comparison with bulk membrane transport in hepatic cells.
|
| Abstract |
Transport of the recycling marker transferrin was analysed in polarized hepatic HepG2 cells using quantitative fluorescence microscopy and mathematical modelling. A detailed map and kinetic model for transport of transferrin in hepatic cells was developed. Fluorescent transferrin was found to be transported sequentially through basolateral SE (sorting endosomes) to a SAC/ARC (subapical compartment/apical recycling compartment). DiI (di-indocarbocyanine) lipid probes of different acyl chain length (DiIC12 and DiIC16) co-localized with transferrin in basolateral SE and in the SAC/ARC. By kinetic comparison of hepatic transport of transferrin and labelled HDL (high-density lipoprotein), it is shown that transport of transferrin from SE to the SAC/ARC follows a default pathway together with HDL. Kinetic modelling of fluorescence data provides an identical half-time for SE-to-SAC/ARC transport of transferrin and fluorescent HDL (t(1/2)=4.2 min). Fluorescent transferrin was found to recycle with a half-time of t(1/2)=12.9 min from the SAC/ARC to the basolateral cell surface of HepG2 cells. In contrast with HDL, targeting of labelled transferrin from the SAC/ARC to the apical biliary canaliculus was negligible. The results indicate that transport from basolateral hepatic SE to the SAC/ARC represents a bulk flow process and that polarized sorting occurs mainly at the level of the SAC/ARC.
|
|---|---|
| Authors | Daniel Wüstner |
| Journal | The Biochemical journal (Biochem J) Vol. 400 Issue 2 Pg. 267-80 (Dec 01 2006) ISSN: 1470-8728 [Electronic] England |
| PMID | 16879100 (Publication Type: Journal Article, Research Support, Non-U.S. Gov't) |
| Chemical References |
|
| Topics |
|
Join CureHunter, for free Research Interface BASIC access!
Realize the full power of the drug-disease research graph!