Cloning and characterization of CXIP1, a novel PICOT domain-containing Arabidopsis protein that associates with CAX1

被引:59
作者
Cheng, NH
Hirschi, KD
机构
[1] Baylor Coll Med, USDA, ARS, Childrens Nutr Res Ctr, Houston, TX 77030 USA
[2] Baylor Coll Med, Dept Human & Mol Genet, Houston, TX 77030 USA
[3] Texas A&M Univ, Vegetable & Fruit Improvement Ctr, College Stn, TX 77845 USA
关键词
D O I
10.1074/jbc.M210883200
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
Regulation of Ca2+ transporters is a vital component of signaling. The Arabidopsis H+/Ca2+ exchanger CAX1 contains an N-terminal autoinhibitory domain that prevents Ca2+ transport when CAX1 is heterologously expressed in yeast. Using a yeast screen, we have identified three different proteins that activate CAX1. One of these, CXIP1 (CAX-interacting protein-1; 19.3 kDa) has amino acid similarity to the C terminus of PICOT (protein kinase C-interacting cousin of thioredoxin) proteins. Although PICOT proteins are found in a variety of organisms, a function has not been previously ascribed to a plant PICOT protein. We demonstrate that CXIP1 activated the CAX1 homolog CAX4, but not CAX2 or CAX3. An Arabidopsis homolog of CXIP1 (CXIP2) weakly activated CAX4, but not CAX1. In a yeast two-hybrid assay, CXIP1 interacted with the N terminus of CAX1. In competition analysis, CXIP1 and a CAX1 N-terminal peptide appeared to bind to similar N-terminal domains of CAX1. Chimeric CAX3 constructs containing the N terminus of CAX1 were activated by CXIP1. In Arabidopsis, CXIP1 transcripts, like CAX1, accumulated in response to different metal conditions. This work thus characterizes a new class of signaling molecules in plants that may regulate CAX transporters in vivo.
引用
收藏
页码:6503 / 6509
页数:7
相关论文
共 36 条
[1]   Yet another plant thioredoxin [J].
Balmer, Y ;
Buchanan, BB .
TRENDS IN PLANT SCIENCE, 2002, 7 (05) :191-193
[2]   Characterization of CAX4, an Arabidopsis H+/cation antiporter [J].
Cheng, NH ;
Pittman, JK ;
Shigaki, T ;
Hirschi, KD .
PLANT PHYSIOLOGY, 2002, 128 (04) :1245-1254
[3]  
CHENG NH, 2003, IN PRESS PLANT CELL
[4]  
Cunningham KW, 1996, MOL CELL BIOL, V16, P2226
[5]   Dissecting calcium oscillators in plant cells [J].
Harper, JF .
TRENDS IN PLANT SCIENCE, 2001, 6 (09) :395-397
[6]  
HARPER JW, 1993, CELL, V75, P805
[7]   Vacuolar H+/Ca2+ transport:: who's directing the traffic? [J].
Hirschi, K .
TRENDS IN PLANT SCIENCE, 2001, 6 (03) :100-104
[8]   Expression of Arabidopsis CAX2 in tobacco.: Altered metal accumulation and increased manganese tolerance [J].
Hirschi, KD ;
Korenkov, VD ;
Wilganowski, NL ;
Wagner, GJ .
PLANT PHYSIOLOGY, 2000, 124 (01) :125-133
[9]   CAX1, an H+/Ca2+ antiporter from Arabidopsis [J].
Hirschi, KD ;
Zhen, RG ;
Cunningham, KW ;
Rea, PA ;
Fink, GR .
PROCEEDINGS OF THE NATIONAL ACADEMY OF SCIENCES OF THE UNITED STATES OF AMERICA, 1996, 93 (16) :8782-8786
[10]   Expression of Arabidopsis CAX1 in tobacco:: Altered calcium homeostasis and increased stress sensitivity [J].
Hirschi, KD .
PLANT CELL, 1999, 11 (11) :2113-2122