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Science 20 November 1987:
Vol. 238. no. 4830, pp. 1112 - 1114
DOI: 10.1126/science.238.4830.1112
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Articles

Stop-Transfer Regions Do Not Halt Translocation of Proteins into Chloroplasts

THOMAS H. LUBBEN 1, JOERN BANSBERG 1, and KENNETH KEEGSTRA 1

1 Department of Botany, University of Wisconsin, Madison, WI 53706.

Protein targeting in eukaryotic cells is determined by several topogenic signals. Among these are stop-transfer regions, which halt translocation of proteins across the endoplasmic reticulum membrane. Two different stop-transfer regions were incorporated into precursors for a chloroplast protein, the small subunit of ribulose-1,5-bisphosphate carboxylase/oxygenase. Both chimeric proteins were imported into chloroplasts and did not accumulate in the envelope membranes. Thus, the stop-transfer signals did not function during chloroplast protein import. These observations support the hypothesis that the mechanism for translocation of proteins across the chloroplast envelope is significantly different from that for translocation across the endoplasmic reticulum membrane.

Submitted on June 8, 1987
Accepted on July 31, 1987


THIS ARTICLE HAS BEEN CITED BY OTHER ARTICLES:
Positive Charges Determine the Topology and Functionality of the Transmembrane Domain in the Chloroplastic Outer Envelope Protein Toc34.
T. May and J. Soll (1998)
J. Cell Biol. 141, 895-904
   Abstract »    Full Text »    PDF »
Identification of a Translocation Intermediate Occupying Functional Protein Import Sites in the Chloroplastic Envelope Membrane.
J. E. Froehlich and K. Keegstra (1997)
J. Biol. Chem. 272, 8077-8082
   Abstract »    Full Text »    PDF »


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