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Mechanisms and effects of retention of over-expressed aquaporin AtPIP2;1 in the endoplasmic reticulum.
- Source :
-
Traffic (Copenhagen, Denmark) [Traffic] 2011 Apr; Vol. 12 (4), pp. 473-82. Date of Electronic Publication: 2011 Feb 01. - Publication Year :
- 2011
-
Abstract
- Plasma membrane intrinsic proteins (PIPs) are aquaporins that mediate water transport across the plant plasma membrane (PM). The present work addresses, using Arabidopsis AtPIP2;1 as a model, the mechanisms and significance of trafficking of newly synthesized PIPs from the endoplasmic reticulum (ER) to the Golgi apparatus. A functional diacidic export motif (Asp4-Val5-Glu6) was identified in the N-terminal tail of AtPIP2;1, using expression in transgenic Arabidopsis of site-directed mutants tagged with the green fluorescent protein (GFP). Confocal fluorescence imaging and a novel fluorescence recovery after photobleaching application based on the distinct diffusion of PM and intracellular AtPIP2;1-GFP forms revealed a retention in the ER of diacidic mutated forms, but with quantitative differences. Thus, the individual role of the two acidic Asp4 and Glu6 residues was established. In addition, expression in transgenic Arabidopsis of ER-retained AtPIP2;1-GFP constructs reduced the root hydraulic conductivity. Co-expression of AtPIP2;1-GFP and AtPIP1;4-mCherry constructs suggested that ER-retained AtPIP2;1-GFP may interact with other PIPs to hamper their trafficking to the PM, thereby contributing to inhibition of root cell hydraulic conductivity.<br /> (© 2011 John Wiley & Sons A/S.)
- Subjects :
- Amino Acid Motifs
Aquaporins chemistry
Aquaporins genetics
Arabidopsis genetics
Arabidopsis metabolism
Arabidopsis Proteins chemistry
Arabidopsis Proteins genetics
Cell Membrane genetics
Cell Membrane metabolism
Endoplasmic Reticulum genetics
Gene Expression Regulation, Plant
Golgi Apparatus metabolism
Green Fluorescent Proteins metabolism
Membrane Proteins chemistry
Membrane Proteins genetics
Membrane Proteins metabolism
Mutagenesis, Site-Directed
Plant Roots genetics
Plant Roots metabolism
Plants, Genetically Modified
Protein Transport
Water metabolism
Aquaporins metabolism
Arabidopsis Proteins metabolism
Endoplasmic Reticulum metabolism
Subjects
Details
- Language :
- English
- ISSN :
- 1600-0854
- Volume :
- 12
- Issue :
- 4
- Database :
- MEDLINE
- Journal :
- Traffic (Copenhagen, Denmark)
- Publication Type :
- Academic Journal
- Accession number :
- 21182578
- Full Text :
- https://doi.org/10.1111/j.1600-0854.2010.01154.x