QUICK SEARCH:   [advanced] Author: Keyword(s): Year:  Vol:  Page:

Vol. 15, Issue 3, 1470-1478, March 2004

This Article Full Text Full Text (PDF) All Versions of this Article: E03-08-0599v1 15/3/1470    most recent Alert me when this article is cited Alert me if a correction is posted Services Similar articles in this journal Similar articles in PubMed Alert me to new issues of the journal Download to citation manager Citing Articles Citing Articles via HighWire Citing Articles via Google Scholar Google Scholar Articles by Goder, V. Articles by Spiess, M. Search for Related Content PubMed PubMed Citation Articles by Goder, V. Articles by Spiess, M.

Sec61p Contributes to Signal Sequence Orientation According to the Positive-Inside Rule

Veit Goder ^*, Tina Junne, and Martin Spiess 

Biozentrum, University of Basel, CH-4056 Basel, Switzerland

Submitted August 18, 2003; Revised October 28, 2003; Accepted November 18, 2003
Monitoring Editor: Reid Gilmore

Protein targeting to the endoplasmic reticulum is mediated by signal or signal-anchor sequences. They also play an important role in protein topogenesis, because their orientation in the translocon determines whether their N- or C-terminal sequence is translocated. Signal orientation is primarily determined by charged residues flanking the hydrophobic core, whereby the more positive end is predominantly positioned to the cytoplasmic side of the membrane, a phenomenon known as the "positive-inside rule." We tested the role of conserved charged residues of Sec61p, the major component of the translocon in Saccharomyces cerevisiae, in orienting signals according to their flanking charges by site-directed mutagenesis by using diagnostic model proteins. Mutation of R67, R74, or E382 in Sec61p reduced C-terminal translocation of a signal-anchor protein with a positive N-terminal flanking sequence and increased it for signal-anchor proteins with positive C-terminal sequences. These mutations produced a stronger effect on substrates with greater charge difference across the hydrophobic core of the signal. For some of the substrates, a charge mutation in Sec61p had a similar effect as one in the substrate polypeptides. Although these three residues do not account for the entire charge effect in signal orientation, the results show that Sec61p contributes to the positive-inside rule.

Abbreviations used: Abbreviations used: CPY, carboxypeptidase Y; ER, endoplasmic reticulum; SRP, signal recognition particle.

^* Present address: Department of Cell Biology, 240 Longwood Ave., Harvard Medical School, Boston, MA 02115.

Corresponding author. E-mail address: martin.spiess{at}unibas.ch.

This article has been cited by other articles:

				M. Bogdanov, J. Xie, and W. Dowhan Lipid-Protein Interactions Drive Membrane Protein Topogenesis in Accordance with the Positive Inside Rule J. Biol. Chem., April 10, 2009; 284(15): 9637 - 9641. [Abstract] [Full Text] [PDF]

				M. Bogdanov, J. Xie, P. Heacock, and W. Dowhan To flip or not to flip: lipid-protein charge interactions are a determinant of final membrane protein topology J. Cell Biol., September 9, 2008; 182(5): 925 - 935. [Abstract] [Full Text] [PDF]

				R. S. Hegde and S.-W. Kang The concept of translocational regulation J. Cell Biol., July 28, 2008; 182(2): 225 - 232. [Abstract] [Full Text] [PDF]

				Y. Amaya, T. Nakai, K. Komaru, M. Tsuneki, and S. Miura Cleavage of the ER-Targeting Signal Sequence of Parathyroid Hormone-related Protein is Cell-Type-Specific and Regulated in Cis by its Nuclear Localization Signal J. Biochem., April 1, 2008; 143(4): 569 - 579. [Abstract] [Full Text] [PDF]

				M. Lerch-Bader, C. Lundin, H. Kim, I. Nilsson, and G. von Heijne Contribution of positively charged flanking residues to the insertion of transmembrane helices into the endoplasmic reticulum PNAS, March 18, 2008; 105(11): 4127 - 4132. [Abstract] [Full Text] [PDF]

				T. Junne, T. Schwede, V. Goder, and M. Spiess Mutations in the Sec61p Channel Affecting Signal Sequence Recognition and Membrane Protein Topology J. Biol. Chem., November 9, 2007; 282(45): 33201 - 33209. [Abstract] [Full Text] [PDF]

				N. Shimohata, S. Nagamori, Y. Akiyama, H. R. Kaback, and K. Ito SecY alterations that impair membrane protein folding and generate a membrane stress J. Cell Biol., January 29, 2007; 176(3): 307 - 317. [Abstract] [Full Text] [PDF]

				T. Junne, T. Schwede, V. Goder, and M. Spiess The Plug Domain of Yeast Sec61p Is Important for Efficient Protein Translocation, but Is Not Essential for Cell Viability Mol. Biol. Cell, September 1, 2006; 17(9): 4063 - 4068. [Abstract] [Full Text] [PDF]

				Y. Kida, F. Morimoto, K. Mihara, and M. Sakaguchi Function of Positive Charges Following Signal-Anchor Sequences during Translocation of the N-terminal Domain J. Biol. Chem., January 13, 2006; 281(2): 1152 - 1158. [Abstract] [Full Text] [PDF]