Previous Article | Next Article ![]()
Journal of Virology, September 2005, p. 11901-11913, Vol. 79, No. 18
0022-538X/05/$08.00+0 doi:10.1128/JVI.79.18.11901-11913.2005
Copyright © 2005, American Society for Microbiology. All Rights Reserved.
Birke Andrea Tews, and
Gregor Meyers*
Institut für Immunologie, Friedrich-Loeffler-Institut, D-72001 Tübingen, Germany
Received 4 February 2005/ Accepted 17 June 2005
The Erns protein is a structural glycoprotein of pestiviruses that lacks a typical membrane anchor sequence and is known to be secreted from the infected cell. However, major amounts of the protein are retained within the cell and attached to the virion by a so far unknown mechanism. Transient-expression studies with cDNA constructs showed that in a steady-state situation, 16% of the protein is found in the supernatant of the transfected cells while 84% appears as intracellular protein. We show here that Erns represents a membrane-bound protein. Membrane binding occurs via the carboxy-terminal region of Erns. By fusion of this sequence to the carboxy terminus of green fluorescent protein (GFP), the subcellular localization of the reporter protein switched from cytosolic to membrane bound. A core sequence of 11 amino acids necessary for membrane binding was elicited in truncation experiments with GFP constructs. However, this peptide is not sufficient to confer membrane anchoring but needs either upstream or downstream accessory sequences. Analyses with different extraction procedures showed that Erns is neither easily stripped from the membrane, like a peripheral membrane protein, nor as tightly membrane bound as a transmembrane protein.
Present address: bioScreen European Veterinary Disease Management Center GmbH, D-48149 Münster, Germany.
This article has been cited by other articles:
Copyright © 2009 by the American Society for Microbiology. For an alternate route to Journals.ASM.org, visit: http://intl-journals.asm.org | More Info»