Interaction specificity of Arabidopsis calcineurin B-like calcium sensors and their target kinases.
Calcium is a critical component in a number of plant signal transduction pathways. A new family of calcium sensors called calcineurin B-like proteins (AtCBLs) have been recently identified from Arabidopsis. These calcium sensors have been shown to interact with a family of protein kinases (CIPKs). Here we report that each individual member of AtCBL family specifically interacts with a subset of CIPKs and present structural basis for the interaction and for the specificity underlying these interactions. Although the C-terminal region of CIPKs is responsible for interaction with AtCBLs, the N-terminal region of CIPKs is also involved in determining the specificity of such interaction. We have also shown that all three EF-hand motifs in AtCBL members are required for the interaction with CIPKs. Several AtCBL members failed to interact with any of the CIPKs presented in this study, suggesting that these AtCBL members either have other CIPKs as targets or they target distinct proteins other than CIPKs. These results may provide structural basis for the functional specificity of CBL family of calcium sensors and their targets.
Kim
K N
KN
Department of Plant and Microbial Biology, University of California, Berkeley, California 94720, USA.
Cheong
Y H
YH
Gupta
R
R
Luan
S
S
D000595:Amino Acid Sequence; D017360:Arabidopsis / Q000737:chemistry / Q000235:genetics* / Q000378:metabolism; D029681:Arabidopsis Proteins; D001665:Binding Sites; D002135:Calcium-Binding Proteins / Q000737:chemistry / Q000235:genetics / Q000378:metabolism*; D018076:DNA, Complementary / Q000737:chemistry / Q000235:genetics; D004274:DNA, Recombinant; D007527:Isoenzymes / Q000235:genetics / Q000378:metabolism; D008969:Molecular Sequence Data; D010957:Plasmids / Q000235:genetics; D011485:Protein Binding; D020033:Protein Isoforms / Q000737:chemistry / Q000235:genetics / Q000378:metabolism; D017346:Protein Serine-Threonine Kinases / Q000737:chemistry / Q000235:genetics / Q000378:metabolism*; D012441:Saccharomyces cerevisiae / Q000235:genetics; D016415:Sequence Alignment; D017422:Sequence Analysis, DNA; D017386:Sequence Homology, Amino Acid; D020798:Two-Hybrid System Techniques
D029681:Arabidopsis Proteins; D002135:Calcium-Binding Proteins; D018076:DNA, Complementary; D004274:DNA, Recombinant; D007527:Isoenzymes; D020033:Protein Isoforms; D017346:Protein Serine-Threonine Kinases; C484078:CBL10 protein, Arabidopsis; C484079:CBL3 protein, Arabidopsis; C483419:calcineurin B-like protein 1, Arabidopsis; C480758:At5g55990 protein, Arabidopsis