Unknown

Dataset Information

0

Visualization of TGN to endosome trafficking through fluorescently labeled MPR and AP-1 in living cells.


ABSTRACT: We have stably expressed in HeLa cells a chimeric protein made of the green fluorescent protein (GFP) fused to the transmembrane and cytoplasmic domains of the mannose 6-phosphate/insulin like growth factor II receptor in order to study its dynamics in living cells. At steady state, the bulk of this chimeric protein (GFP-CI-MPR) localizes to the trans-Golgi network (TGN), but significant amounts are also detected in peripheral, tubulo-vesicular structures and early endosomes as well as at the plasma membrane. Time-lapse videomicroscopy shows that the GFP-CI-MPR is ubiquitously detected in tubular elements that detach from the TGN and move toward the cell periphery, sometimes breaking into smaller tubular fragments. The formation of the TGN-derived tubules is temperature dependent, requires the presence of intact microtubule and actin networks, and is regulated by the ARF-1 GTPase. The TGN-derived tubules fuse with peripheral, tubulo-vesicular structures also containing the GFP-CI-MPR. These structures are highly dynamic, fusing with each other as well as with early endosomes. Time-lapse videomicroscopy performed on HeLa cells coexpressing the CFP-CI-MPR and the AP-1 complex whose gamma-subunit was fused to YFP shows that AP-1 is present not only on the TGN and peripheral CFP-CI-MPR containing structures but also on TGN-derived tubules containing the CFP-CI-MPR. The data support the notion that tubular elements can mediate MPR transport from the TGN to a peripheral, tubulo-vesicular network dynamically connected with the endocytic pathway and that the AP-1 coat may facilitate MPR sorting in the TGN and endosomes.

SUBMITTER: Waguri S 

PROVIDER: S-EPMC140234 | BioStudies | 2003-01-01

REPOSITORIES: biostudies

Similar Datasets

2009-01-01 | S-EPMC2753287 | BioStudies
2014-01-01 | S-EPMC4292573 | BioStudies
2010-01-01 | S-EPMC3133691 | BioStudies
2008-01-01 | S-EPMC2526700 | BioStudies
1000-01-01 | S-EPMC1182289 | BioStudies
2017-01-01 | S-EPMC5674888 | BioStudies
2008-01-01 | S-EPMC2224180 | BioStudies
2006-01-01 | S-EPMC1635343 | BioStudies
2017-01-01 | S-EPMC5674890 | BioStudies
2012-01-01 | S-EPMC3490508 | BioStudies