Protein translocation across the ER requires a functional GTP binding site in the alpha subunit of the signal recognition particle receptor

doi:10.1083/jcb.117.3.493

This Article

	Full Text (PDF, 1508K)
	Alert me when this article is cited
	Citation Map

Services

	Email this article
	Similar articles in this journal
	Similar articles in PubMed
	Alert me to new content in the JCB
	Download to citation manager

Citing Articles

	Citing Articles via HighWire
	Citing Articles via CrossRef
	Citing Articles via Google Scholar

Google Scholar

	Articles by Rapiejko, P. J.
	Articles by Gilmore, R.
	Search for Related Content

PubMed

	PubMed Citation
	Articles by Rapiejko, P. J.
	Articles by Gilmore, R.


Social Bookmarking

	What's this?

ARTICLES

Protein translocation across the ER requires a functional GTP binding site in the alpha subunit of the signal recognition particle receptor

PJ Rapiejko and R Gilmore
Department of Biochemistry and Molecular Biology, University of Massachusetts Medical School, Worcester 01655.

The signal recognition particle (SRP)-mediated translocation of proteins across the RER is a GTP dependent process. Analysis of the primary amino acid sequence of one protein subunit of SRP (SRP54), as well as the alpha subunit of the SRP receptor (SR alpha), has indicated that these proteins contain predicted GTP binding sites. Several point mutations confined to the GTP binding consensus elements of SR alpha were constructed by site specific mutagenesis to define a role for the GTP binding site in SR alpha during protein translocation. The SR alpha mutants were analyzed using an in vitro system wherein SR alpha- deficient microsomal membranes were repopulated with SR alpha by in vitro translation of wild-type or mutant mRNA transcripts. SRP receptors containing SR alpha point mutants were analyzed for their ability to function in protein translocation and to form guanylyl-5'- imidodiphosphate (Gpp[NH]p) stabilized complexes with the SRP. Mutations in SR alpha produced SRP receptors that were either impaired or inactive in protein translocation. These SRP receptors were likewise unable to form Gpp(NH)p stabilized complexes with the SRP. One SR alpha point mutant, Thr 588 to Asn 588, required 50- to 100-fold higher concentrations of GTP relative to the wild-type SR alpha to function in protein translocation. This mutant has provided information on the reaction step in protein translocation that involves the GTP binding site in the alpha subunit of the SRP receptor.
Add to CiteULike CiteULike Add to Complore Complore Add to Connotea Connotea Add to Del.icio.us Del.icio.us Add to Digg Digg Facebook Add to Reddit Reddit Add to Technorati Technorati Twitter What's this?

This article has been cited by other articles:

Mandon, E. C., Jiang, Y., Gilmore, R. (2003). Dual recognition of the ribosome and the signal recognition particle by the SRP receptor during protein targeting to the endoplasmic reticulum. JCB 162: 575-585 [Abstract] [Full Text]
Kanner, E. M., Friedlander, M., Simon, S. M. (2003). Co-translational Targeting and Translocation of the Amino Terminus of Opsin across the Endoplasmic Membrane Requires GTP but Not ATP. J. Biol. Chem. 278: 7920-7926 [Abstract] [Full Text]
Mutka, S. C., Walter, P. (2001). Multifaceted Physiological Response Allows Yeast to Adapt to the Loss of the Signal Recognition Particle-dependent Protein-targeting Pathway. Mol. Biol. Cell 12: 577-588 [Abstract] [Full Text]
Teckman, J. H., Perlmutter, D. H. (2000). Retention of mutant alpha 1-antitrypsin Z in endoplasmic reticulum is associated with an autophagic response. Am. J. Physiol. Gastrointest. Liver Physiol. 279: G961-G974 [Abstract] [Full Text]
Teckman, J. H., Gilmore, R., Perlmutter, D. H. (2000). Role of ubiquitin in proteasomal degradation of mutant alpha 1-antitrypsin Z in the endoplasmic reticulum. Am. J. Physiol. Gastrointest. Liver Physiol. 278: G39-G48 [Abstract] [Full Text]
Bacher, G., Pool, M., Dobberstein, B. (1999). The Ribosome Regulates the Gtpase of the {beta}-Subunit of the Signal Recognition Particle Receptor. JCB 146: 723-730 [Abstract] [Full Text]
Raden, D., Gilmore, R. (1998). Signal Recognition Particle-dependent Targeting of Ribosomes to the Rough Endoplasmic Reticulum in the Absence and Presence of the Nascent Polypeptide-associated Complex. Mol. Biol. Cell 9: 117-130 [Abstract] [Full Text]
Corsi, A. K., Schekman, R. (1996). Mechanism of Polypeptide Translocation into the Endoplasmic Reticulum. J. Biol. Chem. 271: 30299-30302 [Full Text]
Bovia, F, Strub, K (1996). The signal recognition particle and related small cytoplasmic ribonucleoprotein particles. J. Cell Sci. 109: 2601-2608 [Abstract]
Karaplis, A. C., Lim, S.-K., Baba, H., Arnold, A., Kronenberg, H. M. (1995). Inefficient Membrane Targeting, Translocation, and Proteolytic Processing by Signal Peptidase of a Mutant Preproparathyroid Hormone Protein. J. Biol. Chem. 270: 1629-1635 [Abstract] [Full Text]
Lee, A, Tam, R, Belhumeur, P, DiPaolo, T, Clark, M. (1993). Prp20, the Saccharomyces cerevisiae homolog of the regulator of chromosome condensation, RCC1, interacts with double-stranded DNA through a multi-component complex containing GTP-binding proteins. J. Cell Sci. 106: 287-298 [Abstract]
Rapoport, T. (1992). Transport of proteins across the endoplasmic reticulum membrane. Science 258: 931-936 [Abstract]