Cytokinin growth responses in Arabidopsis involve the 26S proteasome subunit RPN12

被引:163
作者
Smalle, J
Kurepa, J
Yang, PZ
Babiychuk, E
Kushnir, S
Durski, A
Vierstra, RD
机构
[1] Univ Wisconsin, Program Mol & Cellular Biol, Madison, WI 53706 USA
[2] Univ Wisconsin, Dept Hort, Madison, WI 53706 USA
[3] State Univ Ghent VIB, Genet Lab, Dept Genet, B-9000 Ghent, Belgium
关键词
D O I
10.1105/tpc.010381
中图分类号
Q5 [生物化学]; Q7 [分子生物学];
学科分类号
071010 ; 081704 ;
摘要
The 26S proteasome is an ATP-dependent eukaryotic protease responsible for degrading many important cell regulators, especially those conjugated with multiple ubiquitins. Bound on both ends of the 20S core protease is a multisubunit regulatory particle that plays a crucial role in substrate selection by an as yet unknown mechanism(s). Here, we show that the RPN12 subunit of the Arabidopsis regulatory particle is involved in cytokinin responses. A T-DNA insertion mutant that affects RPN12a has a decreased rate of leaf formation, reduced root elongation, delayed skotomorphogenesis, and altered growth responses to exogenous cytokinins, suggesting that the mutant has decreased sensitivity to the hormone. The cytokinin-inducible genes CYCD3 and NIA1 are upregulated constitutively in rpn12a-1, indicating that feedback-inhibitory mechanisms also may be altered. rpn12a-1 seedlings also showed changes in auxin-induced growth responses, further illustrating the close interaction between auxin and cytokinin regulation. In yeast, RPN12 is necessary for the G1/S and G2/M transitions of the cell cycle, phases that have been shown to be under cytokinin control in plants. We propose that RPN12a is part of the Arabidopsis 26S proteasome that controls the stability of one or more of the factors involved in cytokinin regulation.
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页码:17 / 32
页数:16
相关论文
共 58 条
[1]   Efficient gene tagging in Arabidopsis thaliana using a gene trap approach [J].
Babiychuk, E ;
Fuanghthong, M ;
VanMontagu, M ;
Inze, D ;
Kushnir, S .
PROCEEDINGS OF THE NATIONAL ACADEMY OF SCIENCES OF THE UNITED STATES OF AMERICA, 1997, 94 (23) :12722-12727
[2]   PERTURBATION OF THE UBIQUITIN SYSTEM CAUSES LEAF CURLING, VASCULAR TISSUE ALTERATIONS AND NECROTIC LESIONS IN A HIGHER-PLANT [J].
BACHMAIR, A ;
BECKER, F ;
MASTERSON, RV ;
SCHELL, J .
EMBO JOURNAL, 1990, 9 (13) :4543-4549
[3]  
Bailly E, 1999, MOL CELL BIOL, V19, P6872
[4]   Induction of competence for elicitation of defense responses in cucumber hypocotyls requires proteasome activity [J].
Becker, J ;
Kempf, R ;
Jeblick, W ;
Kauss, H .
PLANT JOURNAL, 2000, 21 (03) :311-316
[5]   Two genes with similarity to bacterial response regulators are rapidly and specifically induced by cytokinin in Arabidopsis [J].
Brandstatter, I ;
Kieber, JJ .
PLANT CELL, 1998, 10 (06) :1009-1019
[6]   Protein degradation in signaling [J].
Callis, J ;
Vierstra, RD .
CURRENT OPINION IN PLANT BIOLOGY, 2000, 3 (05) :381-386
[7]   CYTOKININ ACTION IS COUPLED TO ETHYLENE IN ITS EFFECTS ON THE INHIBITION OF ROOT AND HYPOCOTYL ELONGATION IN ARABIDOPSIS-THALIANA SEEDLINGS [J].
CARY, AJ ;
LIU, WN ;
HOWELL, SH .
PLANT PHYSIOLOGY, 1995, 107 (04) :1075-1082
[8]   A FUSCA GENE OF ARABIDOPSIS ENCODES A NOVEL PROTEIN ESSENTIAL FOR PLANT DEVELOPMENT [J].
CASTLE, LA ;
MEINKE, DW .
PLANT CELL, 1994, 6 (01) :25-41
[9]   AMP1 - A MUTANT WITH HIGH CYTOKININ LEVELS AND ALTERED EMBRYONIC PATTERN, FASTER VEGETATIVE GROWTH, CONSTITUTIVE PHOTOMORPHOGENESIS AND PRECOCIOUS FLOWERING [J].
CHAUDHURY, AM ;
LETHAM, S ;
CRAIG, S ;
DENNIS, ES .
PLANT JOURNAL, 1993, 4 (06) :907-916
[10]  
ChinAtkins AN, 1996, PLANTA, V198, P549, DOI 10.1007/BF00262641