Yeast protein translocation complex

Isolation of two genes SEB1 and SEB2 encoding proteins homologous to the Sec61 β subunit

Jaana Toikkanen, Evelina Gatti, Kohji Takei, Markku Saloheimo, Vesa M. Olkkonen, Hans Söderlund, Pietro De Camilli, Sirkka Keränen

Research output: Contribution to journalArticle

50 Citations (Scopus)

Abstract

A yeast gene (cDNA clone) was isolated in a screen for suppressors of secretion-defective sec15-1 mutation. This gene encodes a protein homologous to the β subunit of the mammalian Sec61 protein complex functioning in protein translocation into the endoplasmic reticulum (ER). The predicted protein, Seb1p, consists of 82 amino acids and contains one potential membrane-spanning region at the C-terminus but no N-terminal signal sequence. Seb1p shows 30% identity to the mammalian Sec61β subunit and 34% identity to the Arabidopsis thaliana Sec61β subunit. Overexpression of SEBI from a multicopy plasmid suppressed the temperature sensitivity of sec61-2 and sec61-3 mutants. Immunofluorescence and immunoelectron microscopy indicated that Seb1p resides in the ER membranes with the hydrophilic N-terminus exposed to the cytoplasm. The in vitro translated Seb1p was post-translationally inserted into microsomal membranes. As the chromosomal disruption of the SEB1 gene was not lethal, potential homologous genes were screened by heterologous hybridization. The SEB1 homologue thus isolated, SEB2, encodes a protein 53% identical to Seb1p. Disruption of the chromosomal SEB2 was not lethal whereas the double disruption of SEB1 and SEB2 resulted in a temperature-sensitive phenotype. This study further emphasizes the evolutionary conservation of the ER protein translocation apparatus and provides novel genetic tools for its functional analysis. The sequences of SEB1 and SEB2 have been deposited in the EMBL database under Accession Numbers Z47789 and Z50012. respectively. The sequence of the Seb1 protein is identical to that of Sbhlp independently identified by Panzner et al. (Cell 81, 561-570. 1995) using a biochemical approach.

Original languageEnglish
Pages (from-to)425-438
Number of pages14
JournalYeast
Volume12
Issue number5
Publication statusPublished - Apr 1996
Externally publishedYes

Fingerprint

Fungal Proteins
protein transport
Protein Transport
Genes
endoplasmic reticulum
yeasts
Proteins
Endoplasmic Reticulum
lethal genes
genes
proteins
Membranes
gene targeting
signal peptide
membrane potential
Temperature
Immunoelectron Microscopy
fluorescent antibody technique
microscopy
plasmids

Keywords

  • Endoplasmic reticulum
  • Genetic interaction
  • Saccharomyces cerevisiae
  • Seb1p/Sbh1p: Seb2p
  • Sec61β
  • Translocation complex

ASJC Scopus subject areas

  • Agricultural and Biological Sciences (miscellaneous)
  • Biochemistry, Genetics and Molecular Biology(all)
  • Biochemistry
  • Biotechnology
  • Bioengineering
  • Microbiology

Cite this

Toikkanen, J., Gatti, E., Takei, K., Saloheimo, M., Olkkonen, V. M., Söderlund, H., ... Keränen, S. (1996). Yeast protein translocation complex: Isolation of two genes SEB1 and SEB2 encoding proteins homologous to the Sec61 β subunit. Yeast, 12(5), 425-438.

Yeast protein translocation complex : Isolation of two genes SEB1 and SEB2 encoding proteins homologous to the Sec61 β subunit. / Toikkanen, Jaana; Gatti, Evelina; Takei, Kohji; Saloheimo, Markku; Olkkonen, Vesa M.; Söderlund, Hans; De Camilli, Pietro; Keränen, Sirkka.

In: Yeast, Vol. 12, No. 5, 04.1996, p. 425-438.

Research output: Contribution to journalArticle

Toikkanen, J, Gatti, E, Takei, K, Saloheimo, M, Olkkonen, VM, Söderlund, H, De Camilli, P & Keränen, S 1996, 'Yeast protein translocation complex: Isolation of two genes SEB1 and SEB2 encoding proteins homologous to the Sec61 β subunit', Yeast, vol. 12, no. 5, pp. 425-438.
Toikkanen J, Gatti E, Takei K, Saloheimo M, Olkkonen VM, Söderlund H et al. Yeast protein translocation complex: Isolation of two genes SEB1 and SEB2 encoding proteins homologous to the Sec61 β subunit. Yeast. 1996 Apr;12(5):425-438.
Toikkanen, Jaana ; Gatti, Evelina ; Takei, Kohji ; Saloheimo, Markku ; Olkkonen, Vesa M. ; Söderlund, Hans ; De Camilli, Pietro ; Keränen, Sirkka. / Yeast protein translocation complex : Isolation of two genes SEB1 and SEB2 encoding proteins homologous to the Sec61 β subunit. In: Yeast. 1996 ; Vol. 12, No. 5. pp. 425-438.
@article{1802d3e7910641858dc15b2988a08130,
title = "Yeast protein translocation complex: Isolation of two genes SEB1 and SEB2 encoding proteins homologous to the Sec61 β subunit",
abstract = "A yeast gene (cDNA clone) was isolated in a screen for suppressors of secretion-defective sec15-1 mutation. This gene encodes a protein homologous to the β subunit of the mammalian Sec61 protein complex functioning in protein translocation into the endoplasmic reticulum (ER). The predicted protein, Seb1p, consists of 82 amino acids and contains one potential membrane-spanning region at the C-terminus but no N-terminal signal sequence. Seb1p shows 30{\%} identity to the mammalian Sec61β subunit and 34{\%} identity to the Arabidopsis thaliana Sec61β subunit. Overexpression of SEBI from a multicopy plasmid suppressed the temperature sensitivity of sec61-2 and sec61-3 mutants. Immunofluorescence and immunoelectron microscopy indicated that Seb1p resides in the ER membranes with the hydrophilic N-terminus exposed to the cytoplasm. The in vitro translated Seb1p was post-translationally inserted into microsomal membranes. As the chromosomal disruption of the SEB1 gene was not lethal, potential homologous genes were screened by heterologous hybridization. The SEB1 homologue thus isolated, SEB2, encodes a protein 53{\%} identical to Seb1p. Disruption of the chromosomal SEB2 was not lethal whereas the double disruption of SEB1 and SEB2 resulted in a temperature-sensitive phenotype. This study further emphasizes the evolutionary conservation of the ER protein translocation apparatus and provides novel genetic tools for its functional analysis. The sequences of SEB1 and SEB2 have been deposited in the EMBL database under Accession Numbers Z47789 and Z50012. respectively. The sequence of the Seb1 protein is identical to that of Sbhlp independently identified by Panzner et al. (Cell 81, 561-570. 1995) using a biochemical approach.",
keywords = "Endoplasmic reticulum, Genetic interaction, Saccharomyces cerevisiae, Seb1p/Sbh1p: Seb2p, Sec61β, Translocation complex",
author = "Jaana Toikkanen and Evelina Gatti and Kohji Takei and Markku Saloheimo and Olkkonen, {Vesa M.} and Hans S{\"o}derlund and {De Camilli}, Pietro and Sirkka Ker{\"a}nen",
year = "1996",
month = "4",
language = "English",
volume = "12",
pages = "425--438",
journal = "Yeast",
issn = "0749-503X",
publisher = "John Wiley and Sons Ltd",
number = "5",

}

TY - JOUR

T1 - Yeast protein translocation complex

T2 - Isolation of two genes SEB1 and SEB2 encoding proteins homologous to the Sec61 β subunit

AU - Toikkanen, Jaana

AU - Gatti, Evelina

AU - Takei, Kohji

AU - Saloheimo, Markku

AU - Olkkonen, Vesa M.

AU - Söderlund, Hans

AU - De Camilli, Pietro

AU - Keränen, Sirkka

PY - 1996/4

Y1 - 1996/4

N2 - A yeast gene (cDNA clone) was isolated in a screen for suppressors of secretion-defective sec15-1 mutation. This gene encodes a protein homologous to the β subunit of the mammalian Sec61 protein complex functioning in protein translocation into the endoplasmic reticulum (ER). The predicted protein, Seb1p, consists of 82 amino acids and contains one potential membrane-spanning region at the C-terminus but no N-terminal signal sequence. Seb1p shows 30% identity to the mammalian Sec61β subunit and 34% identity to the Arabidopsis thaliana Sec61β subunit. Overexpression of SEBI from a multicopy plasmid suppressed the temperature sensitivity of sec61-2 and sec61-3 mutants. Immunofluorescence and immunoelectron microscopy indicated that Seb1p resides in the ER membranes with the hydrophilic N-terminus exposed to the cytoplasm. The in vitro translated Seb1p was post-translationally inserted into microsomal membranes. As the chromosomal disruption of the SEB1 gene was not lethal, potential homologous genes were screened by heterologous hybridization. The SEB1 homologue thus isolated, SEB2, encodes a protein 53% identical to Seb1p. Disruption of the chromosomal SEB2 was not lethal whereas the double disruption of SEB1 and SEB2 resulted in a temperature-sensitive phenotype. This study further emphasizes the evolutionary conservation of the ER protein translocation apparatus and provides novel genetic tools for its functional analysis. The sequences of SEB1 and SEB2 have been deposited in the EMBL database under Accession Numbers Z47789 and Z50012. respectively. The sequence of the Seb1 protein is identical to that of Sbhlp independently identified by Panzner et al. (Cell 81, 561-570. 1995) using a biochemical approach.

AB - A yeast gene (cDNA clone) was isolated in a screen for suppressors of secretion-defective sec15-1 mutation. This gene encodes a protein homologous to the β subunit of the mammalian Sec61 protein complex functioning in protein translocation into the endoplasmic reticulum (ER). The predicted protein, Seb1p, consists of 82 amino acids and contains one potential membrane-spanning region at the C-terminus but no N-terminal signal sequence. Seb1p shows 30% identity to the mammalian Sec61β subunit and 34% identity to the Arabidopsis thaliana Sec61β subunit. Overexpression of SEBI from a multicopy plasmid suppressed the temperature sensitivity of sec61-2 and sec61-3 mutants. Immunofluorescence and immunoelectron microscopy indicated that Seb1p resides in the ER membranes with the hydrophilic N-terminus exposed to the cytoplasm. The in vitro translated Seb1p was post-translationally inserted into microsomal membranes. As the chromosomal disruption of the SEB1 gene was not lethal, potential homologous genes were screened by heterologous hybridization. The SEB1 homologue thus isolated, SEB2, encodes a protein 53% identical to Seb1p. Disruption of the chromosomal SEB2 was not lethal whereas the double disruption of SEB1 and SEB2 resulted in a temperature-sensitive phenotype. This study further emphasizes the evolutionary conservation of the ER protein translocation apparatus and provides novel genetic tools for its functional analysis. The sequences of SEB1 and SEB2 have been deposited in the EMBL database under Accession Numbers Z47789 and Z50012. respectively. The sequence of the Seb1 protein is identical to that of Sbhlp independently identified by Panzner et al. (Cell 81, 561-570. 1995) using a biochemical approach.

KW - Endoplasmic reticulum

KW - Genetic interaction

KW - Saccharomyces cerevisiae

KW - Seb1p/Sbh1p: Seb2p

KW - Sec61β

KW - Translocation complex

UR - http://www.scopus.com/inward/record.url?scp=0029937560&partnerID=8YFLogxK

UR - http://www.scopus.com/inward/citedby.url?scp=0029937560&partnerID=8YFLogxK

M3 - Article

VL - 12

SP - 425

EP - 438

JO - Yeast

JF - Yeast

SN - 0749-503X

IS - 5

ER -