Skip Navigation

This Article
Right arrow Full Text
Right arrow Full Text (PDF)
Right arrow Alert me when this article is cited
Right arrow Alert me if a correction is posted
Services
Right arrow Email this article to a friend
Right arrow Similar articles in this journal
Right arrow Similar articles in ISI Web of Science
Right arrow Similar articles in PubMed
Right arrow Alert me to new issues of the journal
Right arrow Add to My Personal Archive
Right arrow Download to citation manager
Right arrow Search for citing articles in:
ISI Web of Science (14)
Right arrowRequest Permissions
Google Scholar
Right arrow Articles by Nahm, M. Y.
Right arrow Articles by Bahk, J. D.
Right arrow Search for Related Content
PubMed
Right arrow PubMed Citation
Right arrow Articles by Nahm, M. Y.
Right arrow Articles by Bahk, J. D.
Agricola
Right arrow Articles by Nahm, M. Y.
Right arrow Articles by Bahk, J. D.
Social Bookmarking
Add to CiteULike   Add to Connotea   Add to Del.icio.us  
What's this?

Plant and Cell Physiology, 2003, Vol. 44, No. 12 1341-1349
© 2003 Oxford University Press

Molecular and Biochemical Analyses of OsRab7, a Rice Rab7 Homolog

Min Yeop Nahm1, Sam Woong Kim1, Daejin Yun1, Sang Yeol Lee1,2, Moo Je Cho1,2 and Jeong Dong Bahk1,2,3,4

1 Division of Applied Life Science (BK21), Gyeongsang National University, Jinju, 660-701 Korea
2 Research Institute of Natural Science, Gyeongsang National University, Jinju, 660-701 Korea
3 Agricutural Plant Stress Research Center, Chonnam National University, Gwangju, 500-757 Korea

Rab7 is a small GTP-binding protein important in early to late endosome/lysosome vesicular transport in mammalian cells. We have isolated a Rab7 cDNA clone, OsRab7, from a cold-treated rice cDNA library by the subtraction screening method. The cDNA encodes a polypeptide of 206 amino acids with a calculated molecular mass of about 23 kDa. Its predicted amino acid sequence shows significantly high identity with the sequences of other Rab7 proteins. His-tagged OsRab7 bound to radiolabeled GTP{gamma}S in a specific and stoichiometric manner. Biochemical and structural properties of the Rab7 wild type (WT) protein were compared to those of Q67L and T22N mutants. The detergent 3-([3-cholamidopropyl]dimethylammonio)-1-propane sulfonate (CHAPS) increased the guanine nucleotide binding and hydrolysis activities of Rab7WT. The OsRab7Q67L mutant showed much lower GTPase activity compared to the WT protein untreated with CHAPS, and the T22N mutant showed no GTP binding activity at all. The OsRab7Q67L mutant was constitutively active for guanine nucleotide binding while the T22N mutant (dominant negative) showed no guanine nucleotide binding activity. When bound to GTP, the Rab7WT and the Q67L mutants were protected from tryptic proteolysis. The cleavage pattern of the Rab7T22N mutant, however, was not affected by GTP addition. Northern and Western blot analyses suggested that OsRab7 is distributed in various tissues of rice. Furthermore, expression of a rice Rab7 gene was differentially regulated by various environmental stimuli such as cold, NaCl, dehydration, and ABA. In addition, subcellular localization of OsRab7 was investigated in the Arabidopsis protoplasts by a double-labeling experiment using GFP-fused OsRab7 and FM4-64. GFP-OsRab7 is localized to the vacuolar membrane, suggesting that OsRab7 is implicated in a vesicular transport to the vacuole in plant cells.

4 Corresponding author: E-mail, jdbahk{at}nongae.gsnu.ac.kr; Fax, +82-55-752-7062.


Add to CiteULike CiteULike   Add to Connotea Connotea   Add to Del.icio.us Del.icio.us    What's this?


This article has been cited by other articles:


Home page
 Mol. Cell. Biol.Home page
J. Zhu, X. Fu, Y. D. Koo, J.-K. Zhu, F. E. Jenney Jr., M. W. W. Adams, Y. Zhu, H. Shi, D.-J. Yun, P. M. Hasegawa, et al.
An Enhancer Mutant of Arabidopsis salt overly sensitive 3 Mediates both Ion Homeostasis and the Oxidative Stress Response
Mol. Cell. Biol., July 15, 2007; 27(14): 5214 - 5224.
[Abstract] [Full Text] [PDF]


Disclaimer: Please note that abstracts for content published before 1996 were created through digital scanning and may therefore not exactly replicate the text of the original print issues. All efforts have been made to ensure accuracy, but the Publisher will not be held responsible for any remaining inaccuracies. If you require any further clarification, please contact our Customer Services Department.