Co-Authors:
Sorek, N., Department of Molecular Biology and Ecology of Plants, George S. Wise Faculty of Life Sciences, Tel Aviv University, Tel Aviv 69978, Israel, Energy Biosciences Institute, University of California, Berkeley, CA 94720, United States
Gutman, O., Department of Neurobiology, George S. Wise Faculty of Life Sciences, Tel Aviv University, Tel Aviv 69978, Israel
Bar, E., Department of Field and Vegetable Crops, Agricultural Research Organization, Neve Yáar Research Center, Ramat Yishay 30095, Israel
Abu-Abied, M., Department of Ornamental Horticulture, Agricultural Research Organization, Volcani Center, Bet-Dagan 50250, Israel
Feng, X., Donald Danforth Plant Science Center, St. Louis, MO 63132, United States
Running, M.P., Donald Danforth Plant Science Center, St. Louis, MO 63132, United States
Lewinsohn, E., Department of Field and Vegetable Crops, Agricultural Research Organization, Neve Yáar Research Center, Ramat Yishay 30095, Israel
Ori, N., Robert Smith Institute of Plant Sciences and Genetics of Agriculture, Faculty of Agriculture, Hebrew University of Jerusalem, Rehovot 76100, Israel
Sadot, E., Department of Ornamental Horticulture, Agricultural Research Organization, Volcani Center, Bet-Dagan 50250, Israel
Henis, Y.I., Department of Neurobiology, George S. Wise Faculty of Life Sciences, Tel Aviv University, Tel Aviv 69978, Israel
Yalovsky, S., Department of Molecular Biology and Ecology of Plants, George S. Wise Faculty of Life Sciences, Tel Aviv University, Tel Aviv 69978, Israel
Abstract:
Prenylation primarily by geranylgeranylation is required for membrane attachment and function of type I Rho of Plants (ROPs) and Gγ proteins, while type II ROPs are attached to the plasma membrane by S-acylation. Yet, it is not known how prenylation affects ROP membrane interaction dynamics and what are the functional redundancy and specificity of type I and type II ROPs. Here, we have used the expression of ROPs in mammalian cells together with geranylgeranylation and CaaX prenylation-deficient mutants to answer these questions. Our results show that the mechanism of type II ROP S-acylation and membrane attachment is unique to plants and likely responsible for the viability of plants in the absence of CaaX prenylation activity. The prenylation of ROPs determines their steady-state distribution between the plasma membrane and the cytosol but has little effect on membrane interaction dynamics. In addition, the prenyl group type has only minor effects on ROP function. Phenotypic analysis of the CaaX prenylation-deficient pluripetala mutant epidermal cells revealed that type I ROPs affect cell structure primarily on the adaxial side, while type II ROPs are functional and induce a novel cell division phenotype in this genetic background. Taken together, our studies show how prenyl and S-acyl lipid modifications affect ROP subcellular distribution, membrane interaction dynamics, and function. © 2010 American Society of Plant Biologists.