Is the 6 kDa tobacco etch viral protein a bona fide ERES marker?

The claim that the 6 kDa viral protein (VP) of Tobacco Etch Virus is a marker for ER exit sites (ERES) has been investigated. When transiently expressed as a CFP tagged fusion construct in tobacco mesophyll protoplasts, this integral membrane protein co-localizes with both the COPII coat protein YFP...

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Veröffentlicht in:Journal of experimental botany. - 1985. - 62(2011), 14 vom: 01. Okt., Seite 5013-23
1. Verfasser: Lerich, Alexander (VerfasserIn)
Weitere Verfasser: Langhans, Markus, Sturm, Silke, Robinson, David G
Format: Online-Aufsatz
Sprache:English
Veröffentlicht: 2011
Zugriff auf das übergeordnete Werk:Journal of experimental botany
Schlagworte:Journal Article Research Support, Non-U.S. Gov't Biomarkers Viral Proteins
Beschreibung
Zusammenfassung:The claim that the 6 kDa viral protein (VP) of Tobacco Etch Virus is a marker for ER exit sites (ERES) has been investigated. When transiently expressed as a CFP tagged fusion construct in tobacco mesophyll protoplasts, this integral membrane protein co-localizes with both the COPII coat protein YFP-SEC24 and the Golgi marker Man1-RFP. However, when over-expressed the VP locates to larger spherical structures which co-localize with neither ER nor Golgi markers. Nevertheless, deletion of the COPII interactive N-terminal D(X)E motif causes it to be broadly distributed throughout the ER, supporting the notion that this protein could be an ERES marker. Curiously, whereas brefeldin A (BFA) caused a typical Golgi-stack response (redistribution into the ER) of the VP in leaf epidermal cells, in protoplasts it resulted in the formation of structures identical to those formed by over-expression. However, anomalous results were obtained with protoplasts: when co-expressed with the non-cycling cis-Golgi marker Man1-RFP, a BFA-induced redistribution of the VP-CFP signal into the ER was observed, but, in the presence of the cycling Golgi marker ERD2-YFP, this did not occur. High resolution images of side-on views of Golgi stacks in epidermal cells showed that the 6 kDa VP-CFP signal overlapped considerably more with YFP-SEC24 than with Man1-RFP, indicating that the VP is proportionately more associated with ERES. However, based on a consideration of the structure of its cytoplasmic tail, the scenario that the VP collects at ERES and is transported to the cis-Golgi before being recycled back to the ER, is supported
Beschreibung:Date Completed 13.02.2012
Date Revised 13.12.2023
published: Print-Electronic
Citation Status MEDLINE
ISSN:1460-2431
DOI:10.1093/jxb/err200