The model of intact calmodulin in sbml format was deposited in biomodels database. A wide range of target proteins, or cam binding targets cambts play a key role in regulating those cellular processes through interaction with cam. Recognizes the substrate consensus sequence mvlifxrx2stx3mvlif. In plants, recent reports suggest the occurrence of other types of cam. Representative members of these major classes and one subclass are shown. The protein sequence cannot be greater than 50,000 characters. The extent of binding was determined by scintillation counting each fraction, including the recovered beads. Calmodulin shuttling mediates cytonuclear signaling to. The sr14d mutation is located in the first iq motif, which. Conformational heterogeneity of the calmodulin binding. You may also browse the database that forms the basis of the prediction program. Two distinct calmodulin binding sites in the third intracellular loop.
Now, we have analyzed amino acid residues in the rac1 calmodulin binding domain that are essential for the interaction and assessed their functional contribution in rac1 activation. Kinetic fitting of the cam binding data produced an off rate of 3. Together with biochemical data, the crystal structure suggests that ca2 calmodulin inhibits the binding of kcbp to microtubules by blocking the microtubule binding. Obtained data were processed with the cfx software provided by the manufacturer. Available data for camta protein expression in the brain are. Characterization and functional analysis of the calmodulin. Calmodulin cam is a ubiquitous intracellular calcium sensor that directly binds to and.
Several infants with severe forms of longqt syndrome lqts who displayed. Calmodulin has four efhand motifs that change conformation upon binding calcium ions. Calmodulin is a calcium binding protein that plays a role in signaling pathways, cell cycle progression and proliferation. Transcription activator that binds calmodulin in a calciumdependent manner in vitro pubmed. Sr1 is a calmodulin binding transcription activator that contains a dna binding domain at the n terminus and two calmodulin binding iq motifs in the cterminal 850 to 896 amino acids yang and poovaiah, 2002. Development of microfluidic electrophoresis separation. We previously demonstrated that calmodulin can bind to a region in the cterminal of rac1 and that this interaction is important in the activation of platelet rac1.
Calmodulin decreases the binding of activated cdc42 to iqgap1 isoform 1. Canonical cambinding motifs are defined by the varied spacing of. Review article structural diversity of calmodulin binding. Also, many thanks go to jessica bane for helping analyze ms data, with massmatrix software and for reading some sections of my dissertation. The calciumbinding protein calmodulin cam directly binds to membrane transport proteins to modulate. Calmodulin is a calciumbinding protein ubiquitous in eukaryotic cells. Calmodulinbinding peptide as a removable affinity tag for. Crystal structure of kinesin regulated by ca2 calmodulin.
This animation was produced with crystal structure data of top calmodulin pdb 1cfd and halo calmodulin pdb 3cln using ucsf chimera software. Images were acquired by using fluoview software provided by the manufacturer. The arabidopsis genome contains 6 members of this protein family atcamta16 all containing in addition to a defined cam binding domain a dna binding domain and ankyrinrepeat. Calmodulin cam is a ubiquitous intracellular calcium sensor that directly binds to and modulates a wide variety of enzymes, ion channels, and membrane transport proteins. Conformationspecific detection of calmodulin binding. Calmodulin can also bind to edema factor toxin from the anthrax bacteria. Calmodulin in target binding and recognition wikipedia. Each structure contains one tfp bound in the hydrophobic cleft of t. Calmodulin cam an abbreviation for calciummodulated protein is a multifunctional intermediate calcium binding messenger protein expressed in all eukaryotic cells. Calmodulin cam regulates plant disease responses through its downstream calmodulin binding proteins cambps often by affecting the biosynthesis or signaling of phytohormones, such as jasmonic acid ja and salicylic acid.
Cam communicates changes in intracellular calcium levels by binding to consensus sites known as cam binding motifs in both the presence and absence of calcium. This gene is a member of the calmodulin gene family. Structure edit calmodulin is a small, acidic protein approximately 148 amino acids long 16706 dalton and, as such, is a favorite for testing protein simulation software. This tab holds the annotation information that is stored in the pfam database. Mice homozygous for a knockout allele are viable, fertile and free of obvious cardiac defects, but show reduced pathophysiologic cardiac hypertrophy in response to diverse stress stimuli. Characterization of a calmodulinbinding transcription.
The gene ontology go project is a collaborative effort to address the need for consistent descriptions of gene products across databases. Calcium calmodulin dependent protein kinase an overview. However, how these cambps mediate plant hormones and other stress resistancerelated signaling remains largely unknown. Binding of the proteins to calmodulin depends on the presence of calcium. Calmodulin calcium binding proteins regulate many important cellular processes such as smooth muscle contraction and the crossbridge motion in skeletal muscle. The intracellular calcium sensor protein calmodulin cam interacts with a. Calmodulin has four efhand motifs that change conformation upon binding. The calmodulin binding protein kinase 3 is part of heatshock signal transduction in arabidopsis.
Genomewide identification and expression analysis of. In addition, certain tfs of the bhlh family were shown to directly bind cam, thus inhibiting dna. The cyclic nucleotide binding domain of atcngc2 was modeled using known crystal structures of appropriate proteins as templates and swiss protein database expasy software. Specific regions of the atcngc2 protein were identified that facilitate coincident cam and cyclic nucleotide binding using this modeling approach. There are three major classes and several subclasses of crs motifs in the cam target database. A calmodulin binding protein from arabidopsis has an. A new versatile immobilization tag based on the ultra high affinity and reversibility of the calmodulin calmodulin binding peptide interaction. The webaccessible algorithm calmodulin target database relies on the biochemical and.
Calmodulin binding peptide as a removable affinity tag for protein purification springerlink. Tfp bound in alternate orientations to calciumsaturated calmodulin cdomains. A calmodulinbinding protein from arabidopsis has an. Modulation of calmodulin lobes by different targets. Calmodulin interference with the g binding to i3 and ct regions of the at1a. There are three distinct calmodulin genes dispersed throughout the genome that encode the identical protein, but differ at the nucleotide level. The location of thr286 is highlighted in yellow near the bottom of the structure. Calmodulin is a rather ubiquitous calciumsensing protein belonging to a class of loophelixloop cation binding proteins of similar structure and function. These data were obtained from the analysis of calmodulin binding to an array of all single substitution analogues as well as n and cterminal truncations of.
Binding kinetics of calmodulin with target peptide of. The location of thr305 and thr306 is shown in orange within the cam binding domain in red. Therefore a number of different techniques have been developed for. A new versatile immobilization tag based on the ultra high. Review article structural diversity of calmodulin binding to its target sites henning tidow1,2 and poul nissen1,2 1 centre for membrane pumps in cells and disease pumpkin, aarhus university, denmark.
Sr1, a calmodulinbinding transcription factor, modulates. A multistate model of the camkii dodecamer suggests a. We present a comprehensive profile of amino acid sidechain constraints in a calmodulin cam peptide complex. Bindingdb contains 1,854,767 binding data, for 7,493 protein targets and 820,433 small molecules.
Apo calmodulin binding to the ltype voltagegated calcium. Calcium calmodulin dependent protein kinase that operates in the calciumtriggered camkkcamk1 signaling cascade and, upon calcium influx, regulates transcription activators activity, cell cycle, hormone production, cell differentiation, actin filament organization and neurite outgrowth. Development of microfluidic electrophoresis separation methods for calmodulin binding proteins by 2014 thushara nalin samarasinghe. Screening of cdna expression libraries derived from plants exposed to stress, with 35 slabeled recombinant calmodulin as a probe, revealed a new family of proteins containing a transcription activation domain and two types of dna binding domains designated the cg1 domain and the transcription factor immunoglobulin domain, ankyrin repeats, and a varying number of iq calmodulin. Camk1 calciumcalmodulindependent protein kinase type 1. Systematic delineation of a calmodulin peptide interaction. However, the mechanistic basis of its ability to bind diverse signaling molecules including gpcrs, ion channels, and kinases remains poorly understood. The program will search for possible calmodulinbinding motifs in your protein sequence. Bindingdb is a public, webaccessible database of measured binding affinities, focusing chiefly on the interactions of protein considered to be drugtargets with small, druglike molecules. A calmodulin binding cgcg box dna binding protein family involved in multiple signaling pathways in plants. Calcium binding exposes these nonpolar surfaces of calmodulin, which then bind to nonpolar regions on the target proteins.
The structure shown on the left, from pdb entry 1cfd, shows calmodulin without calcium, and the structure on the right, from pdb entry 1cll, shows calmodulin after calcium binds. A peptide derived from the putative calmodulin binding domain of adenylate cyclase was shown to bind calmodulin. The search may take up to 5 minutes depending on the size and complexity of the sequence. The calmodulin binding domain of myristoylated alaninerich c kinase substrate marcks, which interacts with various targets including calmodulin, actin and membrane lipids, has been suggested to function as a crosstalk point among several signal transduction pathways. The calmodulinbinding transcription activator camta1 is required for longterm memory formation in mice.
Protein purification is an important tool for investigations on protein function, structure analysis, and biotechnological use. Scanning the human proteome for calmodulinbinding proteins. The calmodulinbinding transcription activator camta1 is. Camta6 calmodulinbinding transcription activator 6 arabidopsis. Calmodulin and calmodulinbinding proteins in cystic. Calmodulin binding proteins of 230, 212, 204, 164, 9, 70, 59, 46. Characterization of a calmodulinbinding transcription factor from strawberry fragaria. This inhibition was concentration and timedependent. Iaa3 as a negative control abel and theologis, 1995, which did not bind to calmodulin.