Assay for dual cargo sorting into endoplasmic reticulum exit sites imaged by Super-resolution Confocal Live Imaging Microscopy (SCLIM) v1

2021 ◽  
Author(s):  
Sofia Rodriguez-Gallardo † ◽  
Kazuo Kurokawa †* ◽  
Susana Sabido-Bozo ◽  
Alejandro Cortes-Gomez ◽  
Ana Maria Perez-Linero ◽  
...  
Keyword(s):  
Endoplasmic Reticulum ◽  
Chain Length ◽  
Cell Biology ◽  
Super Resolution ◽  
Live Imaging ◽  
Live Cell ◽  
Restrictive Temperature ◽  
Permissive Temperature ◽  
Er Export ◽  
Cargo Sorting

Understanding how in eukaryotic cells thousands of proteins are sorted from each other through the secretory pathway and delivered to their correct destinations is a central issue of cell biology. We have further investigated in yeast how two distinct types of cargo proteins are sorted into different endoplasmic reticulum (ER) exit sites (ERES) for their differential ER export to the Golgi apparatus. We used an optimized protocol that combines a live cell dual-cargo ER export system with a 3D simultaneous multi-color high-resolution live cell microscopy called Super-resolution Confocal Live Imaging Microscopy (SCLIM). Here, we describe this protocol, which is based on the reversible ER retention of two de novo co-expressed cargos by blocking COPII function upon incubation of the thermo-sensitive COPII allele sec31-1 at restrictive temperature (37ºC). ER export is restored by shifting down to permissive temperature (24ºC) and progressive incorporation of the two different types of cargos into the fluorescently labeled ERES can be then simultaneously captured at 3D high spatial resolution by SCLIM microscopy. By using this protocol, we have shown that newly synthesized glycosylphosphatidylinositol (GPI)-anchored proteins having a very long chain ceramide lipid moiety are clustered and sorted into specialized ERES that are distinct from those used by transmembrane secretory proteins. Furthermore, we showed that the chain length of the ceramide is critical for this sorting selectivity. Therefore, thanks to the presented method we could obtain the first direct in vivo evidence for lipid chain length-based protein cargo sorting into selective ERES.

scholarly journals Assay for dual cargo sorting into endoplasmic reticulum exit sites imaged by 3D Super-resolution Confocal Live Imaging Microscopy (SCLIM)

PLoS ONE ◽  
2021 ◽  
Vol 16 (10) ◽  
pp. e0258111
Author(s):  
Sofia Rodriguez-Gallardo ◽  
Kazuo Kurokawa ◽  
Susana Sabido-Bozo ◽  
Alejandro Cortes-Gomez ◽  
Ana Maria Perez-Linero ◽  
...  
Keyword(s):  
Endoplasmic Reticulum ◽  
Chain Length ◽  
Cell Biology ◽  
Super Resolution ◽  
Live Imaging ◽  
Live Cell ◽  
Restrictive Temperature ◽  
Permissive Temperature ◽  
Er Export ◽  
Cargo Sorting

Understanding how in eukaryotic cells thousands of proteins are sorted from each other through the secretory pathway and delivered to their correct destinations is a central issue of cell biology. We have further investigated in yeast how two distinct types of cargo proteins are sorted into different endoplasmic reticulum (ER) exit sites (ERES) for their differential ER export to the Golgi apparatus. We used an optimized protocol that combines a live cell dual-cargo ER export system with a 3D simultaneous multi-color high-resolution live cell microscopy called Super-resolution Confocal Live Imaging Microscopy (SCLIM). Here, we describe this protocol, which is based on the reversible ER retention of two de novo co-expressed cargos by blocking COPII function upon incubation of the thermo-sensitive COPII allele sec31-1 at restrictive temperature (37°C). ER export is restored by shifting down to permissive temperature (24°C) and progressive incorporation of the two different types of cargos into the fluorescently labelled ERES can be then simultaneously captured at 3D high spatial resolution by SCLIM microscopy. By using this protocol, we have shown that newly synthesized glycosylphosphatidylinositol (GPI)-anchored proteins having a very long chain ceramide lipid moiety are clustered and sorted into specialized ERES that are distinct from those used by transmembrane secretory proteins. Furthermore, we showed that the chain length of the ceramide present in the ER membrane is critical for this sorting selectivity. Therefore, thanks to the presented method we could obtain the first direct in vivo evidence for lipid chain length-based protein cargo sorting into selective ERES.

Assay for dual cargo sorting into endoplasmic reticulum exit sites imaged by super-resolution confocal live imaging microscopy (SCLIM) v1 (protocols.io.bsqnndve)

protocols.io ◽  
2021 ◽  
Author(s):  
Sofia Rodriguez-Gallardo ◽  
Kazuo Kurokawa ◽  
Susana Sabido-Bozo ◽  
Alejandro Cortes-Gomez ◽  
Ana Maria ◽  
...  
Keyword(s):  
Endoplasmic Reticulum ◽  
Super Resolution ◽  
Live Imaging ◽  
Cargo Sorting

scholarly journals Structural and functional characterization of Sec66p, a new subunit of the polypeptide translocation apparatus in the yeast endoplasmic reticulum.

1993 ◽  
Vol 4 (9) ◽  
pp. 931-939 ◽  
Author(s):  
D Feldheim ◽  
K Yoshimura ◽  
A Admon ◽  
R Schekman
Keyword(s):  
Endoplasmic Reticulum ◽  
Signal Sequence ◽  
Functional Characterization ◽  
Yeast Cells ◽  
Temperature Sensitive ◽  
Endoplasmic Reticulum Membrane ◽  
Restrictive Temperature ◽  
Permissive Temperature

SEC66 encodes the 31.5-kDa glycoprotein of the Sec63p complex, an integral endoplasmic reticulum membrane protein complex required for translocation of presecretory proteins in Saccharomyces cerevisiae. DNA sequence analysis of SEC66 predicts a 23-kDa protein with no obvious NH2-terminal signal sequence but with one domain of sufficient length and hydrophobicity to span a lipid bilayer. Antibodies directed against a recombinant form of Sec66p were used to confirm the membrane location of Sec66p and that Sec66p is a glycoprotein of 31.5 kDa. A null mutation in SEC66 renders yeast cells temperature sensitive for growth. sec66 cells accumulate some secretory precursors at a permissive temperature and a variety of precursors at the restrictive temperature. sec66 cells show defects in Sec63p complex formation. Because sec66 cells affect the translocation of some, but not all secretory precursor polypeptides, the role of Sec66p may be to interact with the signal peptide of presecretory proteins.

scholarly journals Genes required for completion of import of proteins into the endoplasmic reticulum in yeast.

1984 ◽  
Vol 98 (1) ◽  
pp. 44-53 ◽  
Author(s):  
S Ferro-Novick ◽  
W Hansen ◽  
I Schauer ◽  
R Schekman
Keyword(s):  
Endoplasmic Reticulum ◽  
Carboxypeptidase Y ◽  
Restrictive Temperature ◽  
Cell Fractionation ◽  
Permissive Temperature ◽  
Cytoplasmic Surface ◽  
Protected Fragment ◽  
Triton X ◽  
Secretory Enzyme ◽  
Er Membrane

Yeast secretory mutants sec53 and sec59 define a posttranslational stage in the penetration of glycoprotein precursors into the endoplasmic reticulum (ER). In the previous report we showed that at the restrictive temperature (37 degrees C) these mutants accumulate enzymatically inactive and incompletely glycosylated forms of the secretory enzyme invertase and the vacuolar enzyme carboxypeptidase Y. Cell fractionation experiments reveal that these precursor forms remain firmly bound to the ER membrane. However, upon return to the permissive temperature (24 degrees C), the invertase precursors are glycosylated, become partially active, and are secreted. Thermoreversible conversion does not require protein synthesis, but does require energy. In contrast to the effect of these mutations, inhibition of oligosaccharide synthesis with tunicamycin at 37 degrees C causes irreversible accumulation of unglycosylated invertase. The effect of the drug is exaggerated by high temperature since unglycosylated invertase synthesized in the presence of tunicamycin at 25 degrees C is secreted. A portion of the invertase polypeptide accumulated at 37 degrees C is preserved when membranes from sec53 and sec59 are treated with trypsin. In the presence of Triton X-100 or saponin, the invertase is degraded completely. The protected fragment appears to represent a portion of the invertase polypeptide that is embedded in or firmly associated with the ER membrane. This association may develop early during the synthesis of invertase, so that in the absence of translocation, some of the completed polypeptide chain remains exposed on the cytoplasmic surface of the ER.

scholarly journals Monensin and FCCP inhibit the intracellular transport of alphavirus membrane glycoproteins

1980 ◽  
Vol 87 (3) ◽  
pp. 783-791 ◽  
Author(s):  
L Kaariainen ◽  
K Hashimoto ◽  
J Saraste ◽  
I Virtanen ◽  
K Penttinen
Keyword(s):  
Endoplasmic Reticulum ◽  
Golgi Apparatus ◽  
Cell Surface ◽  
Intracellular Transport ◽  
Semliki Forest Virus ◽  
Marginal Effect ◽  
Restrictive Temperature ◽  
Permissive Temperature ◽  
Membrane Glycoproteins ◽  
Infected Cells

Temperature-sensitive mutants of semliki forest virus (SFV) and sindbis virus (SIN) were used to study the intracellular transport of virus membrane glycoproteins in infected chicken embryo fibroblasts. When antisera against purified glycoproteins and (125)I- labeled protein A from staphylococcus aureus were used only small amounts of virus glycoproteins were detected at the surface of SFV ts-1 and SIN Ts-10 infected cells incubated at the restrictive temperature (39 degrees C). When the mutant-infected cells were shifted to the permissive temperature (28 degrees C), in the presence of cycloheximide, increasing amounts of virus glycoproteins appeared at the cell surface from 20 to 80 min after the shift. Both monensin (10muM) and carbonylcyanide-p- trifluoromethoxyphenylhydrazone (FCCP; 10-20 muM) inhibited the appearance of virus membrane glycoproteins at the cell surface. Vinblastine sulfate (10 μg/ml) inhibited the transport by approximately 50 percent, whereas cytochalasin B (1 μg/ml) had only a marginal effect. Intracellular distribution of virus glycoproteins in the mutant-infected cells was visualized in double-fluorescence studies using lectins as markers for endoplasmic reticulum and Golgi apparatus. At 39 degrees C, the virus membrane glycoproteins were located at the endoplasmic reticulum, whereas after shift to 28 degrees C, a bright juxtanuclear reticular fluorescence was seen in the location of the Golgi apparatus. In the presence of monensin, the virus glycoproteins could migrate to the Golgi apparatus, although transport to the cell surface did not take place. When the shift was carried out in the presence of FCCP, negligible fluorescence was seen in the Golgi apparatus and the glycoproteins apparently remained in the rough endoplasmic reticulum. A rapid inhibition in the accumulation of virus glycoproteins at the cell surface was obtained when FCCP was added during the active transport period, whereas with monensin there was a delay of approximately 10 min. These results suggest a similar intracellular pathway in the maturation of both plasma membrane and secretory glycoproteins.

scholarly journals New insights into protein secretion: TANGO1 runs rings around the COPII coat

2017 ◽  
Vol 216 (4) ◽  
pp. 859-861 ◽  
Author(s):  
Benjamin S. Glick
Keyword(s):  
Endoplasmic Reticulum ◽  
Protein Secretion ◽  
Super Resolution ◽  
Cell Biol ◽  
Er Exit Sites ◽  
Er Export ◽  
Super Resolution Microscopy

In this issue, Liu et al. (2017. J. Cell Biol. https://doi.org/10.1083/jcb.201611088) and Raote et al. (2017. J. Cell Biol. https://doi.org/10.1083/jcb.201608080) use super-resolution microscopy to visualize large COPII-coated endoplasmic reticulum (ER) export carriers. Rings of TANGO1 surround COPII, implicating TANGO1 in organizing ER exit sites and in regulating COPII coat dynamics and geometry.

Sign in / Sign up

Export Citation Format

Share Document