Abstract
Newly synthesized eukaryotic membrane proteins must be integrated into the membrane of the endoplasmic reticulum with the correct topology to enable the subsequent acquisition of the correctly folded, functional conformation. Here, an analysis is presented of N-terminal glycosylation and steady-state membrane orientation of a series of truncation mutants of the seven-helix protein rhodopsin expressed in COS-1 cells. Mutants containing one, three, or five N-terminal transmembrane segments of rhodopsin, as well as mutants containing only the first transmembrane segment, but with hydrophilic extensions at the C-terminus were studied. The findings demonstrate that the C-terminal transmembrane segments play a crucial role in determining the final orientation of rhodopsin, and that the commitment to the correct orientation occurs only after the synthesis of at least three transmembrane segments. The experiments also suggest that the molecular machinery involved in the integration of a newly synthesized seven-helix membrane protein into the endoplasmic reticulum membrane is sensitive to the overall hydrophobicity of the sequence that follows the first transmembrane segment.
| Original language | English (US) |
|---|---|
| Pages (from-to) | 165-174 |
| Number of pages | 10 |
| Journal | Molecular Membrane Biology |
| Volume | 17 |
| Issue number | 3 |
| State | Published - 2000 |
| Externally published | Yes |
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Keywords
- G protein-coupled receptor
- Glycosylation
- Membrane protein biogenesis
- Topology
- Truncation mutant
ASJC Scopus subject areas
- Cell Biology
Cite this
Integration of deletion mutants of bovine rhodopsin into the membrane of the endoplasmic reticulum. / Heymann, J. A W; Subramaniam, S.
In: Molecular Membrane Biology, Vol. 17, No. 3, 2000, p. 165-174.Research output: Contribution to journal › Article
}
TY - JOUR
T1 - Integration of deletion mutants of bovine rhodopsin into the membrane of the endoplasmic reticulum
AU - Heymann, J. A W
AU - Subramaniam, S.
PY - 2000
Y1 - 2000
N2 - Newly synthesized eukaryotic membrane proteins must be integrated into the membrane of the endoplasmic reticulum with the correct topology to enable the subsequent acquisition of the correctly folded, functional conformation. Here, an analysis is presented of N-terminal glycosylation and steady-state membrane orientation of a series of truncation mutants of the seven-helix protein rhodopsin expressed in COS-1 cells. Mutants containing one, three, or five N-terminal transmembrane segments of rhodopsin, as well as mutants containing only the first transmembrane segment, but with hydrophilic extensions at the C-terminus were studied. The findings demonstrate that the C-terminal transmembrane segments play a crucial role in determining the final orientation of rhodopsin, and that the commitment to the correct orientation occurs only after the synthesis of at least three transmembrane segments. The experiments also suggest that the molecular machinery involved in the integration of a newly synthesized seven-helix membrane protein into the endoplasmic reticulum membrane is sensitive to the overall hydrophobicity of the sequence that follows the first transmembrane segment.
AB - Newly synthesized eukaryotic membrane proteins must be integrated into the membrane of the endoplasmic reticulum with the correct topology to enable the subsequent acquisition of the correctly folded, functional conformation. Here, an analysis is presented of N-terminal glycosylation and steady-state membrane orientation of a series of truncation mutants of the seven-helix protein rhodopsin expressed in COS-1 cells. Mutants containing one, three, or five N-terminal transmembrane segments of rhodopsin, as well as mutants containing only the first transmembrane segment, but with hydrophilic extensions at the C-terminus were studied. The findings demonstrate that the C-terminal transmembrane segments play a crucial role in determining the final orientation of rhodopsin, and that the commitment to the correct orientation occurs only after the synthesis of at least three transmembrane segments. The experiments also suggest that the molecular machinery involved in the integration of a newly synthesized seven-helix membrane protein into the endoplasmic reticulum membrane is sensitive to the overall hydrophobicity of the sequence that follows the first transmembrane segment.
KW - G protein-coupled receptor
KW - Glycosylation
KW - Membrane protein biogenesis
KW - Topology
KW - Truncation mutant
UR - http://www.scopus.com/inward/record.url?scp=0033647283&partnerID=8YFLogxK
UR - http://www.scopus.com/inward/citedby.url?scp=0033647283&partnerID=8YFLogxK
M3 - Article
C2 - 11128975
AN - SCOPUS:0033647283
VL - 17
SP - 165
EP - 174
JO - Molecular Membrane Biology
JF - Molecular Membrane Biology
SN - 0968-7688
IS - 3
ER -