First published online November 30, 2007; 10.1105/tpc.107.053876
The Plant Cell 19:3504-3515 (2007)
© 2007 American Society of Plant Biologists
VPS9a, the Common Activator for Two Distinct Types of Rab5 GTPases, Is Essential for the Development of Arabidopsis thaliana[W]
Tatsuaki Goha,b,1,
Wakana Uchidab,1,
Satoko Arakawab,2,
Emi Itoa,
Tomoko Dainobua,
Kazuo Ebinea,
Masaki Takeuchib,3,
Ken Satob,4,
Takashi Uedaa,5 and
Akihiko Nakanoa,b
a Department of Biological Sciences, Graduate School of Science, University of Tokyo, Bunkyo-ku, Tokyo 113-0033, Japan
b Molecular Membrane Biology Laboratory, RIKEN Discovery Research Institute, Wako, Saitama 351-0198, Japan
5 Address correspondence to tueda{at}biol.s.u-tokyo.ac.jp.
Rab5, a subfamily of Rab GTPases, regulates a variety of endosomal functions as a molecular switch. Arabidopsis thaliana has two different types of Rab5-member GTPases: conventional type, ARA7 and RHA1, and a plant-specific type, ARA6. We found that only one guanine nucleotide exchange factor (GEF), named VPS9a, can activate all Rab5 members to GTP-bound forms in vitro in spite of their diverged structures. In the vps9a-1 mutant, whose GEF activity is completely lost, embryogenesis was arrested at the torpedo stage. Green fluorescent protein (GFP)–ARA7 and ARA6-GFP were diffused in cytosol like GDP-fixed mutants of Rab5 in vps9a-1, indicating that both types of GTPase are regulated by VPS9a. In the leaky vps9a-2 mutant, elongation of the primary root was severely affected. Overexpression of the GTP-fixed form of ARA7 suppressed the vps9a-2 mutation, but overexpression of ARA6 had no apparent effects. These results indicate that the two types of plant Rab5 members are functionally differentiated, even though they are regulated by the same activator, VPS9a.
This article has been cited by other articles:
|
|
|
|
 
H. Pinheiro, M. Samalova, N. Geldner, J. Chory, A. Martinez, and I. Moore
Genetic evidence that the higher plant Rab-D1 and Rab-D2 GTPases exhibit distinct but overlapping interactions in the early secretory pathway
J. Cell Sci.,
October 15, 2009;
122(20):
3749 - 3758.
[Abstract]
[Full Text]
[PDF]
|
|
|
|
|
|
|
M. Shirakawa, H. Ueda, T. Shimada, C. Nishiyama, and I. Hara-Nishimura
Vacuolar SNAREs Function in the Formation of the Leaf Vascular Network by Regulating Auxin Distribution
Plant Cell Physiol.,
July 1, 2009;
50(7):
1319 - 1328.
[Abstract]
[Full Text]
[PDF]
|
|
|
|
|
|
|
S. J. Liljegren, M. E. Leslie, L. Darnielle, M. W. Lewis, S. M. Taylor, R. Luo, N. Geldner, J. Chory, P. A. Randazzo, M. F. Yanofsky, et al.
Regulation of membrane trafficking and organ separation by the NEVERSHED ARF-GAP protein
Development,
June 1, 2009;
136(11):
1909 - 1918.
[Abstract]
[Full Text]
[PDF]
|
|
|
|
|
|
|
S. Naramoto, S. Sawa, K. Koizumi, T. Uemura, T. Ueda, J. Friml, A. Nakano, and H. Fukuda
Phosphoinositide-dependent regulation of VAN3 ARF-GAP localization and activity essential for vascular tissue continuity in plants
Development,
May 1, 2009;
136(9):
1529 - 1538.
[Abstract]
[Full Text]
[PDF]
|
|
|
|
|
|
|
H. Eubel, E. H. Meyer, N. L. Taylor, J. D. Bussell, N. O'Toole, J. L. Heazlewood, I. Castleden, I. D. Small, S. M. Smith, and A. H. Millar
Novel Proteins, Putative Membrane Transporters, and an Integrated Metabolic Network Are Revealed by Quantitative Proteomic Analysis of Arabidopsis Cell Culture Peroxisomes
Plant Physiology,
December 1, 2008;
148(4):
1809 - 1829.
[Abstract]
[Full Text]
[PDF]
|
|
|
|
|
|
|
E. Rojo and J. Denecke
What Is Moving in the Secretory Pathway of Plants?
Plant Physiology,
August 1, 2008;
147(4):
1493 - 1503.
[Full Text]
[PDF]
|
|
|
|
|
|
|
E. Nielsen, A. Y. Cheung, and T. Ueda
The Regulatory RAB and ARF GTPases for Vesicular Trafficking
Plant Physiology,
August 1, 2008;
147(4):
1516 - 1526.
[Full Text]
[PDF]
|
|
|
|
|
