Related Experiment Video
Updated: Sep 28, 2026

A Competent Hepatocyte Model Examining Hepatitis B Virus Entry through Sodium Taurocholate Cotransporting Polypeptide as a Therapeutic Target
Published on: May 10, 2022
Concentrative nucleoside transporter (rCNT1) is targeted to the apical membrane through the hepatic transcytotic
Sylvie Duflot1, Maria Calvo, F Javier Casado
1Departament de Bioquimica i Biologia Molecular, Facultat de Biologia, Institut d'Investigacions Biomèdiques August Pi i Sunyer (IDIBAPS), Facultat de Medicina, Universitat de Barcelona, E-08028, Barcelona, Spain.
Abstract:
The Na+-dependent nucleoside transporter CNT1 has been identified in a caveolin-enriched plasma membrane fraction (CEF), in transcytotic endosomes, and in canalicular membranes isolated from quiescent rat liver in which the transporter appears to be biologically active. CNT1 was also detected, albeit in small amounts, in the early/sorting endosomes. Plasma membrane preparations enriched in basolateral markers showed Na+-dependent nucleoside transport activity that is mostly, if not exclusively, accounted for by CNT2, a transporter protein which was not detected in CEF nor in the endosomal fractions. These data are consistent with different localization and trafficking pathways of the two isoforms in hepatocytes. CNT1 is the first transporter which is reported to follow the transcytotic pathway to be inserted on the apical side of liver parenchymal cells.
Related Concept Videos
Carrier-Mediated Transport
Active transport involves two types of membrane-spanning transporters: uptake and efflux. Uptake transporters are expressed in the small...
Directionality of Nuclear Transport
Protein Transport into the Inner Mitochondrial Membrane
Transport of mitochondrial precursors across the TIM23 channel is driven by...
Non-LTR Retrotransposons
Nuclear Localization Signals and Import
Membrane Transporters
Transporters are mainly composed of alpha-helices, built from bundles of ten or more helices traversing the plasma membrane. The solute-binding sites are located midway, where some of the helices are broken or distorted, making space for the binding site through...
