Journal
PLANT CELL
Volume 12, Issue 7, Pages 1179-1201Publisher
OXFORD UNIV PRESS INC
DOI: 10.1105/tpc.12.7.1179
Keywords
-
Ask authors/readers for more resources
The tomato Cf-9 disease resistance gene encodes a type I membrane protein carrying a cytosolic dilysine motif. In mammals and yeast, this motif promotes the retrieval of type I membrane proteins from the Golgi apparatus to the endoplasmic reticulum (ER). To test whether the C-terminal KKXX signal of Cf-9 is functional as a retrieval motif and to investigate its role in plants, green fluorescent protein (GFP) was fused to the transmembrane domain of Cf-9 and expressed in yeast, Arabidopsis, and tobacco cells. The fusion protein was targeted to the ER in each of these expression systems, and mutation of the KKXX motif to NNXX led to secretion of the fusion protein. In yeast, the mutant protein reached the vacuole, but plants secreted it as a soluble protein after proteolytic removal of the transmembrane domain. Triple hemagglutinin (HA)-tagged full-length Cf-9 was also targeted to the ER in tobacco cells, and cleavage was also observed for the NNXX mutant protein, suggesting an endoprotease recognition site located within the Cf-9 lumenal sequence common to both the GFP- and the HA-tagged fusions. Our results indicate that the KKXX motif confers ER localization in plants as well as mammals and yeast and that Cf-9 is a resident protein of the ER.
Authors
I am an author on this paper
Click your name to claim this paper and add it to your profile.
Reviews
Recommended
No Data Available