Visualization of ER-to-Golgi transport in living cells reveals a sequential mode of action for COPII and COPI.
Exocytic transport from the endoplasmic reticulum (ER) to the Golgi complex has been visualized in living cells using a chimera of the temperature-sensitive glycoprotein of vesicular stomatitis virus and green fluorescent protein (ts-G-GFP[ct]). Upon shifting to permissive temperature, ts-G-GFP(ct) concentrates into COPII-positive structures close to the ER, which then build up to form an intermediate compartment or transport complex, containing ERGIC-53 and the KDEL receptor, where COPII is replaced by COPI. These structures appear heterogenous and move in a microtubule-dependent manner toward the Golgi complex. Our results suggest a sequential mode of COPII and COPI action and indicate that the transport complexes are ER-to-Golgi transport intermediates from which COPI may be involved in recycling material to the ER.
Scales
S J
SJ
Department of Cell Biology, University of Geneva Sciences III, Switzerland.
Pepperkok
R
R
Kreis
T E
TE
D000818:Animals; D001692:Biological Transport / Q000502:physiology; D002352:Carrier Proteins / Q000378:metabolism*; D002451:Cell Compartmentation / Q000502:physiology; D002462:Cell Membrane / Q000378:metabolism; D002522:Chlorocebus aethiops; D020756:Coatomer Protein; D004721:Endoplasmic Reticulum / Q000378:metabolism*; D005089:Exocytosis / Q000502:physiology; D006056:Golgi Apparatus / Q000378:metabolism*; D049452:Green Fluorescent Proteins; D008164:Luminescent Proteins; D008562:Membrane Glycoproteins; D008565:Membrane Proteins / Q000378:metabolism*; D008870:Microtubules / Q000378:metabolism; D010750:Phosphoproteins / Q000378:metabolism*; D011993:Recombinant Fusion Proteins / Q000378:metabolism; D029701:Saccharomyces cerevisiae Proteins; D013696:Temperature; D014709:Vero Cells; D033921:Vesicular Transport Proteins; D014759:Viral Envelope Proteins
D002352:Carrier Proteins; D020756:Coatomer Protein; C028391:G protein, vesicular stomatitis virus; D008164:Luminescent Proteins; D008562:Membrane Glycoproteins; D008565:Membrane Proteins; D010750:Phosphoproteins; D011993:Recombinant Fusion Proteins; C106113:SEC31 protein, S cerevisiae; D029701:Saccharomyces cerevisiae Proteins; D033921:Vesicular Transport Proteins; D014759:Viral Envelope Proteins; D049452:Green Fluorescent Proteins