Characterisation of calmodulin binding to cyclic nucleotide-gated ion channels from Arabidopsis thaliana.
The recently identified cyclic nucleotide-gated ion channels (AtCNGCs) from Arabidopsis thaliana have the ability to bind calmodulin. Using two different methods, we mapped the binding site of AtCNGC1 to the last predicted alpha helix of the cyclic nucleotide binding domain. This is in contrast to CNGCs from animals, where the calmodulin binding site is located in the N-terminus, implying that different mechanisms for CNGC modulation have evolved in animals and plants. Furthermore, we demonstrate that AtCNGC1 and AtCNGC2 have different calmodulin binding affinities and we provide evidence for target specificities among calmodulin isoforms.
Köhler
C
C
Universität Freiburg, Institut für Biologie II, Zellbiologie, Schänzlestr. 1, D-79104, Freiburg, Germany.
Neuhaus
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G
D020816:Amino Acid Motifs; D000595:Amino Acid Sequence; D017360:Arabidopsis; D001665:Binding Sites; D002147:Calmodulin / Q000737:chemistry / Q000235:genetics / Q000302:isolation & purification / Q000378:metabolism*; D054815:Cyclic Nucleotide-Gated Cation Channels; D007473:Ion Channels / Q000737:chemistry* / Q000235:genetics / Q000378:metabolism*; D008969:Molecular Sequence Data; D011485:Protein Binding; D020033:Protein Isoforms / Q000737:chemistry / Q000235:genetics / Q000302:isolation & purification / Q000378:metabolism; D011993:Recombinant Fusion Proteins / Q000737:chemistry / Q000235:genetics / Q000302:isolation & purification / Q000378:metabolism; D012441:Saccharomyces cerevisiae / Q000235:genetics / Q000254:growth & development; D016415:Sequence Alignment; D017384:Sequence Deletion / Q000235:genetics; D013379:Substrate Specificity; D013816:Thermodynamics; D020798:Two-Hybrid System Techniques
D002147:Calmodulin; D054815:Cyclic Nucleotide-Gated Cation Channels; D007473:Ion Channels; D020033:Protein Isoforms; D011993:Recombinant Fusion Proteins