The transmembrane domain is sufficient for Sbh1p function, its association with the Sec61 complex, and interaction with Rtn1p

Dejiang Feng, Xueqiang Zhao, Christina Soromani, Jaana Toikkanen, Karin Römisch, Shruthi S. Vembar, Jeffrey L. Brodsky, Sirkka Keränen, Jussi Jäntti

Research output: Contribution to journalArticleScientificpeer-review

10 Citations (Scopus)

Abstract

The Sec61 protein translocation complex in the endoplasmic reticulum (ER) membrane is composed of three subunits: The a-subunit, called Sec61p in yeast, is a multi-spanning membrane protein that forms the protein conducting channel. The functions of the smaller, carboxy-terminally tail-anchored ß subunit Sbh1p, its close homologue Sbh2p, and the  subunit Sss1p are not well understood. Here we show that co-translational protein translocation into the ER is reduced in sbh1 sbh2 cells, whereas there is a limited reduction of post-translational tranlocation and no effect on export of a mutant form of alfa-factor precursor for ER-associated degradation in the cytosol. The translocation defect and the temperature-sensitive growth phenotype of sbh1 sbh2 cells were rescued by expression of the trans-membrane domain of Sbh1p alone and the Sbh1p trans-membrane domain was sufficient for coimmunoprecipitation with Sec61p and Sss1p. Furthermore, we show that Sbh1p co-precipitates with the ER trans-membrane protein Rtn1p. Sbh1p-Rtn1p complexes appear not to contain Sss1p and Sec61p. Our results define the trans-membrane domain as the minimal functional domain of the Sec61ß homologue Sbh1p in ER translocation, identify a novel interaction partner for Shb1p and imply that Sbh1p has additional functions that are not directly linked to protein translocation in association with the Sec61-complex.
Original languageEnglish
Pages (from-to)30618-30628
JournalJournal of Biological Chemistry
Volume282
Issue number42
DOIs
Publication statusPublished - 2007
MoE publication typeA1 Journal article-refereed

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Endoplasmic Reticulum
Protein Transport
Association reactions
Membranes
Membrane Proteins
Proteins
Endoplasmic Reticulum-Associated Degradation
Cytosol
Yeast
Precipitates
Yeasts
Phenotype
Degradation
Defects
Temperature
Growth

Keywords

  • proteins
  • Sec proteins
  • yeasts
  • gene expression

Cite this

Feng, Dejiang ; Zhao, Xueqiang ; Soromani, Christina ; Toikkanen, Jaana ; Römisch, Karin ; Vembar, Shruthi S. ; Brodsky, Jeffrey L. ; Keränen, Sirkka ; Jäntti, Jussi. / The transmembrane domain is sufficient for Sbh1p function, its association with the Sec61 complex, and interaction with Rtn1p. In: Journal of Biological Chemistry. 2007 ; Vol. 282, No. 42. pp. 30618-30628.
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title = "The transmembrane domain is sufficient for Sbh1p function, its association with the Sec61 complex, and interaction with Rtn1p",
abstract = "The Sec61 protein translocation complex in the endoplasmic reticulum (ER) membrane is composed of three subunits: The a-subunit, called Sec61p in yeast, is a multi-spanning membrane protein that forms the protein conducting channel. The functions of the smaller, carboxy-terminally tail-anchored {\ss} subunit Sbh1p, its close homologue Sbh2p, and the  subunit Sss1p are not well understood. Here we show that co-translational protein translocation into the ER is reduced in sbh1 sbh2 cells, whereas there is a limited reduction of post-translational tranlocation and no effect on export of a mutant form of alfa-factor precursor for ER-associated degradation in the cytosol. The translocation defect and the temperature-sensitive growth phenotype of sbh1 sbh2 cells were rescued by expression of the trans-membrane domain of Sbh1p alone and the Sbh1p trans-membrane domain was sufficient for coimmunoprecipitation with Sec61p and Sss1p. Furthermore, we show that Sbh1p co-precipitates with the ER trans-membrane protein Rtn1p. Sbh1p-Rtn1p complexes appear not to contain Sss1p and Sec61p. Our results define the trans-membrane domain as the minimal functional domain of the Sec61{\ss} homologue Sbh1p in ER translocation, identify a novel interaction partner for Shb1p and imply that Sbh1p has additional functions that are not directly linked to protein translocation in association with the Sec61-complex.",
keywords = "proteins, Sec proteins, yeasts, gene expression",
author = "Dejiang Feng and Xueqiang Zhao and Christina Soromani and Jaana Toikkanen and Karin R{\"o}misch and Vembar, {Shruthi S.} and Brodsky, {Jeffrey L.} and Sirkka Ker{\"a}nen and Jussi J{\"a}ntti",
year = "2007",
doi = "10.1074/jbc.M701840200",
language = "English",
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pages = "30618--30628",
journal = "Journal of Biological Chemistry",
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Feng, D, Zhao, X, Soromani, C, Toikkanen, J, Römisch, K, Vembar, SS, Brodsky, JL, Keränen, S & Jäntti, J 2007, 'The transmembrane domain is sufficient for Sbh1p function, its association with the Sec61 complex, and interaction with Rtn1p', Journal of Biological Chemistry, vol. 282, no. 42, pp. 30618-30628. https://doi.org/10.1074/jbc.M701840200

The transmembrane domain is sufficient for Sbh1p function, its association with the Sec61 complex, and interaction with Rtn1p. / Feng, Dejiang; Zhao, Xueqiang; Soromani, Christina; Toikkanen, Jaana; Römisch, Karin; Vembar, Shruthi S.; Brodsky, Jeffrey L.; Keränen, Sirkka; Jäntti, Jussi.

In: Journal of Biological Chemistry, Vol. 282, No. 42, 2007, p. 30618-30628.

Research output: Contribution to journalArticleScientificpeer-review

TY - JOUR

T1 - The transmembrane domain is sufficient for Sbh1p function, its association with the Sec61 complex, and interaction with Rtn1p

AU - Feng, Dejiang

AU - Zhao, Xueqiang

AU - Soromani, Christina

AU - Toikkanen, Jaana

AU - Römisch, Karin

AU - Vembar, Shruthi S.

AU - Brodsky, Jeffrey L.

AU - Keränen, Sirkka

AU - Jäntti, Jussi

PY - 2007

Y1 - 2007

N2 - The Sec61 protein translocation complex in the endoplasmic reticulum (ER) membrane is composed of three subunits: The a-subunit, called Sec61p in yeast, is a multi-spanning membrane protein that forms the protein conducting channel. The functions of the smaller, carboxy-terminally tail-anchored ß subunit Sbh1p, its close homologue Sbh2p, and the  subunit Sss1p are not well understood. Here we show that co-translational protein translocation into the ER is reduced in sbh1 sbh2 cells, whereas there is a limited reduction of post-translational tranlocation and no effect on export of a mutant form of alfa-factor precursor for ER-associated degradation in the cytosol. The translocation defect and the temperature-sensitive growth phenotype of sbh1 sbh2 cells were rescued by expression of the trans-membrane domain of Sbh1p alone and the Sbh1p trans-membrane domain was sufficient for coimmunoprecipitation with Sec61p and Sss1p. Furthermore, we show that Sbh1p co-precipitates with the ER trans-membrane protein Rtn1p. Sbh1p-Rtn1p complexes appear not to contain Sss1p and Sec61p. Our results define the trans-membrane domain as the minimal functional domain of the Sec61ß homologue Sbh1p in ER translocation, identify a novel interaction partner for Shb1p and imply that Sbh1p has additional functions that are not directly linked to protein translocation in association with the Sec61-complex.

AB - The Sec61 protein translocation complex in the endoplasmic reticulum (ER) membrane is composed of three subunits: The a-subunit, called Sec61p in yeast, is a multi-spanning membrane protein that forms the protein conducting channel. The functions of the smaller, carboxy-terminally tail-anchored ß subunit Sbh1p, its close homologue Sbh2p, and the  subunit Sss1p are not well understood. Here we show that co-translational protein translocation into the ER is reduced in sbh1 sbh2 cells, whereas there is a limited reduction of post-translational tranlocation and no effect on export of a mutant form of alfa-factor precursor for ER-associated degradation in the cytosol. The translocation defect and the temperature-sensitive growth phenotype of sbh1 sbh2 cells were rescued by expression of the trans-membrane domain of Sbh1p alone and the Sbh1p trans-membrane domain was sufficient for coimmunoprecipitation with Sec61p and Sss1p. Furthermore, we show that Sbh1p co-precipitates with the ER trans-membrane protein Rtn1p. Sbh1p-Rtn1p complexes appear not to contain Sss1p and Sec61p. Our results define the trans-membrane domain as the minimal functional domain of the Sec61ß homologue Sbh1p in ER translocation, identify a novel interaction partner for Shb1p and imply that Sbh1p has additional functions that are not directly linked to protein translocation in association with the Sec61-complex.

KW - proteins

KW - Sec proteins

KW - yeasts

KW - gene expression

U2 - 10.1074/jbc.M701840200

DO - 10.1074/jbc.M701840200

M3 - Article

VL - 282

SP - 30618

EP - 30628

JO - Journal of Biological Chemistry

JF - Journal of Biological Chemistry

SN - 0021-9258

IS - 42

ER -