Arabidopsis has two functional orthologs of the yeast V-ATPase assembly factor Vma21p

How individual protein subunits assemble into the higher order structure of a protein complex is not well understood. Four proteins dedicated to the assembly of the V0 subcomplex of the V-adenosine triphosphatase (V-ATPase) in the endoplasmic reticulum (ER) have been identified in yeast, but their p...

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Bibliographic Details
Main Authors: Neubert, Christoph (Author) , Schumacher, Karin (Author)
Format: Article (Journal)
Language:English
Published: 6 August 2008
In: Traffic
Year: 2008, Volume: 9, Issue: 10, Pages: 1618-1628
ISSN:1447-2538
DOI:10.1111/j.1600-0854.2008.00799.x
Online Access:Verlag, Volltext: http://dx.doi.org/10.1111/j.1600-0854.2008.00799.x
Verlag, Volltext: http://onlinelibrary.wiley.com/doi/10.1111/j.1600-0854.2008.00799.x/abstract
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Author Notes:Christoph Neubert, Laurie A. Graham, Eric W. Black-Maier, Emily M. Coonrod, Tzu-Yin Liu, York-Dieter Stierhof, Thorsten Seidel, Tom H. Stevens, Karin Schumacher
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Summary:How individual protein subunits assemble into the higher order structure of a protein complex is not well understood. Four proteins dedicated to the assembly of the V0 subcomplex of the V-adenosine triphosphatase (V-ATPase) in the endoplasmic reticulum (ER) have been identified in yeast, but their precise mode of molecular action remains to be identified. In contrast to the highly conserved subunits of the V-ATPase, orthologs of the yeast assembly factors are not easily identified based on sequence similarity. We show in this study that two ER-localized Arabidopsis proteins that share only 25% sequence identity with Vma21p can functionally replace this yeast assembly factor. Loss of AtVMA21a function in RNA interference seedlings caused impaired cell expansion and changes in Golgi morphology characteristic for plants with reduced V-ATPase activity, and we therefore conclude that AtVMA21a is the first V-ATPase assembly factor identified in a multicellular eukaryote. Moreover, VMA21p acts as a dedicated ER escort chaperone, a class of substrate-specific accessory proteins so far not identified in higher plants.
Item Description:Gesehen am 09.05.2017
Physical Description:Online Resource
ISSN:1447-2538
DOI:10.1111/j.1600-0854.2008.00799.x