Note to users. If you're seeing this message, it means that your browser cannot find this page's style/presentation instructions -- or possibly that you are using a browser that does not support current Web standards. Find out more about why this message is appearing, and what you can do to make your experience of our site the best it can be.


Logo for

Plant Physiology 124 (4): 1625-1636

Copyright © 2000 by the American Society of Plant Physiologists.

Plant Physiol, December 2000, Vol. 124, pp. 1625-1636

Arabidopsis RopGAPs Are a Novel Family of Rho GTPase-Activating Proteins that Require the Cdc42/Rac-Interactive Binding Motif for Rop-Specific GTPase Stimulation1

Guang Wu, Hai Li, and Zhenbiao Yang*

Department of Botany and Plant Sciences, University of California, Riverside, California 92521 (G.W., Z.Y.); Department of Plant Biology, Ohio State University, Columbus, Ohio 43210 (G.W.); and Plant Molecular Biology Laboratory, Salk Institute, San Diego, California 92186 (H.L.)

The plant-specific Rop subfamily of Rho GTPases, most closely related to the mammalian Cdc42 and Rac GTPases, plays an important role in the regulation of calcium-dependent pollen tube growth, H2O2-mediated cell death, and many other processes in plants. In a search for Rop interactors using the two-hybrid method, we identified a family of Rho GTPase-activating proteins (GAP) from Arabidopsis, termed RopGAPs. In addition to a GAP catalytic domain, RopGAPs contain a Cdc42/Rac-interactive binding (CRIB) motif known to allow Cdc42/Rac effector proteins to bind activated Cdc42/Rac. This novel combination of a GAP domain with a CRIB motif is widespread in higher plants and is unique to the regulation of the Rop GTPase. A critical role for CRIB in the regulation of in vitro RopGAP activity was demonstrated using point and deletion mutations. Both types of mutants have drastically reduced capacities to stimulate the intrinsic Rop GTPase activity and to bind Rop. Furthermore, RopGAPs preferentially stimulate the GTPase activity of Rop, but not Cdc42 in a CRIB-dependent manner. In vitro binding assays show that the RopGAP CRIB domain interacts with GTP- and GDP-bound forms of Rop, as well as the transitional state of Rop mimicked by aluminum fluoride. The CRIB domain also promotes the association of the GAP domain with the GDP-bound Rop, as does aluminum fluoride. These results reveal a novel CRIB-dependent mechanism for the regulation of the plant-specific family of Rho GAPs. We propose that the CRIB domain facilitates the formation of or enhanced GAP-mediated stabilization of the transitional state of the Rop GTPase.

1 This work was supported by the National Science Foundation (grant no. MCB-S9724047 to Z.Y.).

* Corresponding author; e-mail zhenbiao.yang{at}; fax 909-787-4437.

© 2000 American Society of Plant Physiologists

A Cdc42- and Rac-interactive binding (CRIB) domain mediates functions of coronin.
K. Swaminathan, A. Muller-Taubenberger, J. Faix, F. Rivero, and A. A. Noegel (2014)
PNAS 111, E25-E33
   Abstract »    Full Text »    PDF »
CPK3-phosphorylated RhoGDI1 is essential in the development of Arabidopsis seedlings and leaf epidermal cells.
Y. Wu, S. Zhao, H. Tian, Y. He, W. Xiong, L. Guo, and Y. Wu (2013)
J. Exp. Bot. 64, 3327-3338
   Abstract »    Full Text »    PDF »
Initiation of Cell Wall Pattern by a Rho- and Microtubule-Driven Symmetry Breaking.
Y. Oda and H. Fukuda (2012)
Science 337, 1333-1336
   Abstract »    Full Text »    PDF »
Barley ROP Binding Kinase1 Is Involved in Microtubule Organization and in Basal Penetration Resistance to the Barley Powdery Mildew Fungus.
C. Huesmann, T. Reiner, C. Hoefle, J. Preuss, M. E. Jurca, M. Domoki, A. Feher, and R. Huckelhoven (2012)
Plant Physiology 159, 311-320
   Abstract »    Full Text »    PDF »
RopGEF7 Regulates PLETHORA-Dependent Maintenance of the Root Stem Cell Niche in Arabidopsis.
M. Chen, H. Liu, J. Kong, Y. Yang, N. Zhang, R. Li, J. Yue, J. Huang, C. Li, A. Y. Cheung, et al. (2011)
PLANT CELL 23, 2880-2894
   Abstract »    Full Text »    PDF »
A Barley ROP GTPase ACTIVATING PROTEIN Associates with Microtubules and Regulates Entry of the Barley Powdery Mildew Fungus into Leaf Epidermal Cells.
C. Hoefle, C. Huesmann, H. Schultheiss, F. Bornke, G. Hensel, J. Kumlehn, and R. Huckelhoven (2011)
PLANT CELL 23, 2422-2439
   Abstract »    Full Text »    PDF »
Physcomitrella patens: a model to investigate the role of RAC/ROP GTPase signalling in tip growth.
D. M. Eklund, E. M. Svensson, and B. Kost (2010)
J. Exp. Bot.
   Abstract »    Full Text »    PDF »
Pollen-tube tip growth requires a balance of lateral propagation and global inhibition of Rho-family GTPase activity.
J.-U. Hwang, G. Wu, A. Yan, Y.-J. Lee, C. S. Grierson, and Z. Yang (2010)
J. Cell Sci. 123, 340-350
   Abstract »    Full Text »    PDF »
Putative Vitis vinifera Rop- and Rab-GAP-, GEF-, and GDI-interacting proteins uncovered with novel methods for public genomic and EST database analysis.
P. Abbal and C. Tesniere (2010)
J. Exp. Bot. 61, 65-74
   Abstract »    Full Text »    PDF »
RIP1 (ROP Interactive Partner 1)/ICR1 Marks Pollen Germination Sites and May Act in the ROP1 Pathway in the Control of Polarized Pollen Growth.
S. Li, Y. Gu, A. Yan, E. Lord, and Z.-B. Yang (2008)
Mol Plant 1, 1021-1035
   Abstract »    Full Text »    PDF »
A Novel RNA-Binding Protein Associated with Cell Plate Formation.
L. Ma, B. Xie, Z. Hong, D. P. S. Verma, and Z. Zhang (2008)
Plant Physiology 148, 223-234
   Abstract »    Full Text »    PDF »
A distinct mechanism regulating a pollen-specific guanine nucleotide exchange factor for the small GTPase Rop in Arabidopsis thaliana.
Y. Zhang and S. McCormick (2007)
PNAS 104, 18830-18835
   Abstract »    Full Text »    PDF »
NADPH oxidase-dependent reactive oxygen species formation required for root hair growth depends on ROP GTPase.
M. A. Jones, M. J. Raymond, Z. Yang, and N. Smirnoff (2007)
J. Exp. Bot. 58, 1261-1270
   Abstract »    Full Text »    PDF »
Tobacco RhoGTPase ACTIVATING PROTEIN1 Spatially Restricts Signaling of RAC/Rop to the Apex of Pollen Tubes.
U. Klahre and B. Kost (2006)
PLANT CELL 18, 3033-3046
   Abstract »    Full Text »    PDF »
Petunia Phospholipase C1 Is Involved in Pollen Tube Growth.
P. E. Dowd, S. Coursol, A. L. Skirpan, T.-h. Kao, and S. Gilroy (2006)
PLANT CELL 18, 1438-1453
   Abstract »    Full Text »    PDF »
Members of a Novel Class of Arabidopsis Rho Guanine Nucleotide Exchange Factors Control Rho GTPase-Dependent Polar Growth.
Y. Gu, S. Li, E. M. Lord, and Z. Yang (2006)
PLANT CELL 18, 366-381
   Abstract »    Full Text »    PDF »
Oscillatory ROP GTPase Activation Leads the Oscillatory Polarized Growth of Pollen Tubes.
J.-U. Hwang, Y. Gu, Y.-J. Lee, and Z. Yang (2005)
Mol. Biol. Cell 16, 5385-5399
   Abstract »    Full Text »    PDF »
A Rho family GTPase controls actin dynamics and tip growth via two counteracting downstream pathways in pollen tubes.
Y. Gu, Y. Fu, P. Dowd, S. Li, V. Vernoud, S. Gilroy, and Z. Yang (2005)
J. Cell Biol. 169, 127-138
   Abstract »    Full Text »    PDF »
Phosphatidic Acid Induces Leaf Cell Death in Arabidopsis by Activating the Rho-Related Small G Protein GTPase-Mediated Pathway of Reactive Oxygen Species Generation.
J. Park, Y. Gu, Y. Lee, Z. Yang, and Y. Lee (2004)
Plant Physiology 134, 129-136
   Abstract »    Full Text »    PDF »
Concerted Regulation of Cell Dynamics by BNIP-2 and Cdc42GAP Homology/Sec14p-like, Proline-rich, and GTPase-activating Protein Domains of a Novel Rho GTPase-activating Protein, BPGAP1.
X. Shang, Y. T. Zhou, and B. C. Low (2003)
J. Biol. Chem. 278, 45903-45914
   Abstract »    Full Text »    PDF »
Analysis of the Small GTPase Gene Superfamily of Arabidopsis.
V. Vernoud, A. C. Horton, Z. Yang, and E. Nielsen (2003)
Plant Physiology 131, 1191-1208
   Abstract »    Full Text »    PDF »
ROP GTPase regulation of pollen tube growth through the dynamics of tip-localized F-actin.
Y. Gu, V. Vernoud, Y. Fu, and Z. Yang (2003)
J. Exp. Bot. 54, 93-101
   Abstract »    Full Text »    PDF »
Plant Rac-Like GTPases Are Activated by Auxin and Mediate Auxin-Responsive Gene Expression.
L.-z. Tao, A. Y. Cheung, and H.-m. Wu (2002)
PLANT CELL 14, 2745-2760
   Abstract »    Full Text »    PDF »
RopGAP4-Dependent Rop GTPase Rheostat Control of Arabidopsis Oxygen Deprivation Tolerance.
A. Baxter-Burrell, Z. Yang, P. S. Springer, and J. Bailey-Serres (2002)
Science 296, 2026-2028
   Abstract »    Full Text »    PDF »
Small GTPases: Versatile Signaling Switches in Plants.
Z. Yang (2002)
PLANT CELL 14, S375-S388
   Full Text »    PDF »
A Genome-Wide Analysis of Arabidopsis Rop-Interactive CRIB Motif-Containing Proteins That Act as Rop GTPase Targets.
G. Wu, Y. Gu, S. Li, and Z. Yang (2001)
PLANT CELL 13, 2841-2856
   Abstract »    Full Text »    PDF »
The Rop GTPase Switch Controls Multiple Developmental Processes in Arabidopsis.
H. Li, J.-J. Shen, Z.-L. Zheng, Y. Lin, and Z. Yang (2001)
Plant Physiology 126, 670-684
   Abstract »    Full Text »    PDF »
ROP Gtpase-Dependent Dynamics of Tip-Localized F-Actin Controls Tip Growth in Pollen Tubes.
Y. Fu, G. Wu, and Z. Yang (2001)
J. Cell Biol. 152, 1019-1032
   Abstract »    Full Text »    PDF »

To Advertise     Find Products

Science Signaling. ISSN 1937-9145 (online), 1945-0877 (print). Pre-2008: Science's STKE. ISSN 1525-8882