The comparison of rat liver rough endoplasmic reticulum membrane proteins before and after in vitro removal of its bound ribosomes

1975 ◽  
Vol 2 (2) ◽  
pp. 113-118 ◽  
Author(s):  
Henryk H. Czosnek ◽  
Nathan De Groot ◽  
Abraham A. Hochberg
Keyword(s):  
Endoplasmic Reticulum ◽  
Membrane Proteins ◽  
Rat Liver ◽  
Rough Endoplasmic Reticulum ◽  
Endoplasmic Reticulum Membrane ◽  
Before And After

The Role of Membrane Proteins and Phospholipids in the Interaction of Ribosomes with Endoplasmic Reticulum Membranes

1975 ◽  
Vol 53 (9) ◽  
pp. 1039-1045 ◽  
Author(s):  
Serge Jothy ◽  
Jean-Louis Bilodeau ◽  
Henry Simpkins
Keyword(s):  
Endoplasmic Reticulum ◽  
Membrane Proteins ◽  
Rat Liver ◽  
Rough Endoplasmic Reticulum ◽  
Binding Sites ◽  
Molecular Weights ◽  
Low Concentrations ◽  
Phospholipid Headgroups ◽  
Hydrolysis Of

Hydrolysis of the membrane proteins and phospholipid headgroups of rat liver rough endoplasmic reticulum membranes showed that the ribosomal binding sites involve membrane proteins susceptible to low concentrations of trypsin, chymotrypsin, and papain. Three membrane proteins having molecular weights of 120 000, 93 000 and 36 000 are found to be altered by trypsin and chymotrypsin treatment. Also the polar headgroup of phosphatidylinositol appears to play a role in the binding process.

Expression of Viral Membrane Proteins from Cloned cDNA by Microinjection into Eucaryotic Cell Nuclei

1982 ◽  
Vol 40 ◽  
pp. 26-29
Author(s):  
H. Garoff ◽  
Cl. Kondor-Koch
Keyword(s):  
Endoplasmic Reticulum ◽  
Membrane Proteins ◽  
Signal Sequence ◽  
Endoplasmic Reticulum Membrane ◽  
In Vitro Mutagenesis ◽  
Cell Nuclei ◽  
Eucaryotic Cell ◽  
Cloned Cdna ◽  
The Relationship

The relationship between a protein's structure and its function can be explored in detail by in vitro mutagenesis of a cloned DNA molecule encoding the protein and expression of its mutagenized form in a eucaryotic cell. This will be a useful approach to study the assembly of spanning viral or plasma membrane proteins into the endoplasmic reticulum membrane and their transport to the cell surface. Questions that could be answered using this technique include:Is the signal sequence alone sufficient for translocation of a polypeptide chain across the endoplasmic reticulum membrane? Is a cytoplasmic protein (e.g. a viral capsid protein) translocated when linked to a signal sequence?

scholarly journals Electrophoretic protein blots as aids in choosing fixatives for immunocytochemistry.

1988 ◽  
Vol 36 (4) ◽  
pp. 441-446 ◽  
Author(s):  
J Paiement ◽  
L Roy
Keyword(s):  
Endoplasmic Reticulum ◽  
Rat Liver ◽  
Rough Endoplasmic Reticulum ◽  
Liver Protein ◽  
Polyacrylamide Gels ◽  
Immunogold Technique ◽  
Immunocytochemical Studies

We used electrophoretic protein blots prepared from polyacrylamide gels to test the effect of different fixatives on the antigenicity of rough endoplasmic reticulum (RER) peptides from rat liver. Protein blots were prepared by the procedure of Towbin et al. (Proc Natl Acad Sci USA 76:4350, 1979), treated with different fixatives, rinsed to inactivate non-specific reactive sites, and then reacted with rabbit polyclonal anti-rat liver RER antibodies, followed by peroxidase-conjugated anti-rabbit antibodies. On the basis of differences in immunostaining densities as determined by densitometry, we found that RER peptides displayed differential sensitivities to various fixatives. Anti-rat liver RER antibodies and the immunogold technique were applied to methacrylate sections of in vitro fixed rat liver rough microsomes. Specific labeling was observed over the microsomes and was shown by quantitation to vary in a similar manner to the immunostaining of specific peptides in protein blots following different fixations. We conclude that protein blots may serve as useful tools for screening the effects of different fixatives on cell antigenicity, and therefore may be helpful in immunocytochemical studies.

scholarly journals Rer1p, a Retrieval Receptor for Endoplasmic Reticulum Membrane Proteins, Is Dynamically Localized to the Golgi Apparatus by Coatomer

2001 ◽  
Vol 152 (5) ◽  
pp. 935-944 ◽  
Author(s):  
Ken Sato ◽  
Miyuki Sato ◽  
Akihiko Nakano
Keyword(s):  
Endoplasmic Reticulum ◽  
Green Fluorescent Protein ◽  
Membrane Proteins ◽  
Golgi Apparatus ◽  
Fluorescent Protein ◽  
Transmembrane Domain ◽  
Endoplasmic Reticulum Membrane ◽  
Golgi Membrane ◽  
Green Fluorescent

Rer1p, a yeast Golgi membrane protein, is required for the retrieval of a set of endoplasmic reticulum (ER) membrane proteins. We present the first evidence that Rer1p directly interacts with the transmembrane domain (TMD) of Sec12p which contains a retrieval signal. A green fluorescent protein (GFP) fusion of Rer1p rapidly cycles between the Golgi and the ER. Either a lesion of coatomer or deletion of the COOH-terminal tail of Rer1p causes its mislocalization to the vacuole. The COOH-terminal Rer1p tail interacts in vitro with a coatomer complex containing α and γ subunits. These findings not only give the proof that Rer1p is a novel type of retrieval receptor recognizing the TMD in the Golgi but also indicate that coatomer actively regulates the function and localization of Rer1p.

scholarly journals Binding of rat liver and hepatoma polyribosomes to stripped rough endoplasmic reticulum in vitro. Biological or an artifact?

1972 ◽  
Vol 130 (1) ◽  
pp. 19-25 ◽  
Author(s):  
A. A. Hochberg ◽  
F. W. Stratman ◽  
Rainer N. Zahlten ◽  
H. P. Morris ◽  
H. A. Lardy
Keyword(s):  
Endoplasmic Reticulum ◽  
Protein Synthesis ◽  
Rat Liver ◽  
Rough Endoplasmic Reticulum ◽  
Trichloroacetic Acid ◽  
Intact Cell ◽  
Biological Significance ◽  
Thiol Groups ◽  
Inhibition Of Protein Synthesis

Exposed thiol groups do not appear to be related to the binding of 32P-labelled polyribosomes to stripped rough endoplasmic reticulum in vitro. Treating stripped rough endoplasmic reticulum with GSSG did not diminish binding of polyribosomes, suggesting that binding in vitro has no correlation with the inhibition of protein synthesis in vitro reported by Kosower et al. (1971). Thiol reagents, which are known to dissociate ribosomes, did not significantly decrease binding of 32P-labelled polyribosomes to stripped rough endoplasmic reticulum. Denaturing the protein of 32P-labelled polyribosomes or stripped rough endoplasmic reticulum of liver or hepatoma with heat, trichloroacetic acid, or HClO4 did not alter the binding in vitro. Therefore, the practice of measuring the binding of 32P-labelled polyribosomes to stripped rough endoplasmic reticulum in vitro (Shires et al., 1971b) is an unsuitable indicator of biological significance in the intact cell.

The in vitro reconstitution of rough endoplasmic reticulum membrane derived from human placenta

Life Sciences ◽  
1977 ◽  
Vol 21 (6) ◽  
pp. 779-788 ◽  
Author(s):  
Alma L. Gal ◽  
Rachel Folman ◽  
Henryk H. Czosnek ◽  
Yoseph Shiklosh ◽  
Nathan de Groot ◽  
...  
Keyword(s):  
Endoplasmic Reticulum ◽  
Rough Endoplasmic Reticulum ◽  
Human Placenta ◽  
Endoplasmic Reticulum Membrane ◽  
In Vitro Reconstitution

scholarly journals A comparative study of the molecular structures of the plasma membranes and the smooth and the rough endoplasmic-reticulum membranes from rat liver

1972 ◽  
Vol 129 (3) ◽  
pp. 781-788 ◽  
Author(s):  
F. Morin ◽  
S. Tay ◽  
H. Simpkins
Keyword(s):  
Endoplasmic Reticulum ◽  
Plasma Membrane ◽  
Rat Liver ◽  
Rough Endoplasmic Reticulum ◽  
Plasma Membranes ◽  
Structural Changes ◽  
Molecular Structures ◽  
Endoplasmic Reticulum Membrane ◽  
Marker Enzyme ◽  
Membrane Phospholipids

Plasma-membrane as well as smooth-, rough- and degranulated-endoplasmic-reticulum-membrane fractions were isolated from the microsomal pellet of rat liver. The purity of these fractions, as determined by marker-enzyme activities, electron microscopy, cholesterol content and RNA content, was found to be adequate for a comparative structural study. Major differences in lipid and protein composition were found to exist between the plasma membrane and the endoplasmic reticulum, but not between the smooth and the rough fractions of the endoplasmic reticulum. Differences in the location of membrane protein thiol groups and the mobility of the membrane phospholipids were observed between the plasma membranes and the endoplasmic reticulum, and these could be explained by differences in protein and lipid composition. However, by employing fluorescence and spin-labelling techniques structural changes were also observed between the smooth and the rough endoplasmic-reticulum fractions. These results suggest that the structural heterogeneity existing between the two latter membrane fractions occurs near or on their membrane surfaces and is not due to the greater number of ribosomes bound to the rough endoplasmic-reticulum fraction.

scholarly journals Targeting of Rough Endoplasmic Reticulum Membrane Proteins and Ribosomes in Invertebrate Neurons

2002 ◽  
Vol 13 (5) ◽  
pp. 1778-1791 ◽  
Author(s):  
Melissa M. Rolls ◽  
David H. Hall ◽  
Martin Victor ◽  
Ernst H. K. Stelzer ◽  
Tom A. Rapoport
Keyword(s):  
Endoplasmic Reticulum ◽  
Caenorhabditis Elegans ◽  
Membrane Proteins ◽  
Cell Body ◽  
Rough Endoplasmic Reticulum ◽  
Protein Targeting ◽  
Fluorescent Protein ◽  
Cell Types ◽  
Endoplasmic Reticulum Membrane ◽  
Unknown Mechanism

The endoplasmic reticulum (ER) is divided into rough and smooth domains (RER and SER). The two domains share most proteins, but RER is enriched in some membrane proteins by an unknown mechanism. We studied RER protein targeting by expressing fluorescent protein fusions to ER membrane proteins in Caenorhabditis elegans. In several cell types RER and general ER proteins colocalized, but in neurons RER proteins were concentrated in the cell body, whereas general ER proteins were also found in neurites. Surprisingly RER membrane proteins diffused rapidly within the cell body, indicating they are not localized by immobilization. Ribosomes were also concentrated in the cell body, suggesting they may be in part responsible for targeting RER membrane proteins.

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