The Arabidopsis endoplasmic reticulum retention receptor functions in yeast.

This is the authors' abstract. We don't add key points for this paper.

Soluble proteins retained in the lumen of the endoplasmic reticulum (ER) contain a carboxyl-terminal tetrapeptide sequence that functions presumably to recycle these proteins from a subsequent compartment. Biochemical and genetic evidence indicate that the ERD2 gene product is the receptor for these ER retention signals. Here we report the identification of a cDNA clone from Arabidopsis thaliana (aERD2) similar in sequence and size to members of the ERD2 gene family. Southern and Northern blot analyses indicate that Arabidopsis contains a single aERD2 gene which is expressed at different levels in various plant tissues. A functional assay demonstrates that the Arabidopsis homologue, unlike the mammalian protein, can complement the lethal phenotype of the erd2 deletion mutant of Saccharomyces cerevisiae, indicating that this protein may have a similar function in plants. As the plant protein may have a binding specificity similar to the human Erd2 protein but can function in yeast, we suggest that the plant homologue is the functional link between yeast and animals.