title: The Signal Sequence Receptor Has a Second Subunit and IsPart of a Translocation Complex in the Endoplasmic Reticulum as Probed by Bifunctional Reagents
creator: Görlich, Dirk
creator: Prehn, Siegfried
creator: Hartmann, Enno
creator: Herz, Joachim
creator: Otto, Albrecht
creator: Kraft, Regine
creator: Wiedmann, Martin
creator: Knespel, Siegne
creator: Dobberstein, Bernhard
creator: Rapoport, Tom A.
subject: ddc-570
subject: 570 Life sciences
description: Bifunctional cross-linking reagents were used to probe the protein environment in the ER membrane of the signal sequence receptor (SSR), a 34-kD integral membrane glycoprotein (Wiedmann, M., T. V. Kurzchalia, E. Hartmarm, and T. A. Rapoport. 1987. Nature [Lond.]. 328:830-833). The proximity of several polypeptides was demonstrated. A 22-kD glycoprotein was identified tightly bound to the 34-kD SSR even after membrane solubilization. The 34-kD polypeptide, now termed otSSR, and the 22-kD polypeptide, the #SSR, represent a heterodimer. We report on the sequence of the/3SSR, its membrane topology, and on the mechanism of its integration into the membrane. Cross-linking also produced dimers of the a-subunit of the SSR indicating that oligomers of the SSR exist in the ER membrane. Various bifunctional cross-linking reagents were used to study the relation to ER membrane proteins of nascent chains of preprolactin and/3-1actamase at different stages of their translocation through the membrane. The predominant cross-linked products obtained in high yields contained the aSSR, indicating in conjunction with previous results that it is a major membrane protein in the neighborhood of translocating nascent chains of secretory proteins. The results support the existence of a translocon, a translocation complex involving the SSR, which constitutes the specific site of protein translocation across the ER membrane.
date: 1990
type: Article
type: info:eu-repo/semantics/article
type: NonPeerReviewed
format: application/pdf
identifier: https://archiv.ub.uni-heidelberg.de/volltextserverhttps://archiv.ub.uni-heidelberg.de/volltextserver/8476/1/Goerlich_1990_JCB.pdf
identifier: DOI:10.11588/heidok.00008476
identifier: urn:nbn:de:bsz:16-opus-84764
identifier:   Görlich, Dirk ; Prehn, Siegfried ; Hartmann, Enno ; Herz, Joachim ; Otto, Albrecht ; Kraft, Regine ; Wiedmann, Martin ; Knespel, Siegne ; Dobberstein, Bernhard ; Rapoport, Tom A.  (1990) The Signal Sequence Receptor Has a Second Subunit and IsPart of a Translocation Complex in the Endoplasmic Reticulum as Probed by Bifunctional Reagents.  The Journal of Cell Biology, 111 (6).  pp. 2283-2294.      
relation: https://archiv.ub.uni-heidelberg.de/volltextserver/8476/
rights: info:eu-repo/semantics/openAccess
rights: http://archiv.ub.uni-heidelberg.de/volltextserver/help/license_urhg.html
language: eng