Cloned (Comment) | Organism |
---|---|
gene CHKA, recombinant expression of His-SUMO-tagged wild-type and mutant enzymes in Escherichia coli strain Rosetta (DE3)pLysS | Homo sapiens |
Crystallization (Comment) | Organism |
---|---|
purified choline kinase catalytic domain of the protein, residues 80-457, and of SH3-ChoKalpha1(60-69) fusion protein, from 0.2 M zinc acetate, 0.1 M imidazole pH 8.0, and 20% w/v PEG 3000, drops of 0.002 ml protein at 10 mg/ml are set at a 1:1 ratio with reservoir solution, 2-3 weeks, X-ray diffraction structure determination and analysis at 1.5 A resolution, structure modeling using the structure of c-Src-SH3 with the NS5A peptide, PDB ID 4QT7, as a model | Homo sapiens |
Protein Variants | Comment | Organism |
---|---|---|
D306A | site-directed mutagenesis, inactive mutant of ChoKalpha1 | Homo sapiens |
additional information | comparison of the c-Src binding potential of ChoK as the full-length (FL) enzyme or with the first 49 (DELTA49) or 79 (DELTA79) residues truncated. The FL and DELTA49 variants include the poly-proline region, whereas the DELTA79 variant does not. All constructs extend up to the C-terminal residue, Val457, overview. The c-Src-ChoKalpha1 interaction occurs with the enzymatically dead D306A variant of ChoKalphaDELTA49, indicating that the association is independent of ChoKalpha1 activity. Both the P61A/P62A and the DELTA62 are difficult to purify and less soluble than their FL, DELTA49, or DELTA79 counterparts, as well as the P59A/P60A or P72A/P73A constructs | Homo sapiens |
P59A/P60A | site-directed mutagenesis | Homo sapiens |
P61A/P62A | site-directed mutagenesis | Homo sapiens |
P72A/P73A | site-directed mutagenesis | Homo sapiens |
Inhibitors | Comment | Organism | Structure |
---|---|---|---|
additional information | chemotherapeutic drug design has centered on stopping the catalytic activity of choline kinase and reducing the downstream metabolites it produces | Homo sapiens |
Metals/Ions | Comment | Organism | Structure |
---|---|---|---|
Mg2+ | required | Homo sapiens |
Natural Substrates | Organism | Comment (Nat. Sub.) | Natural Products | Comment (Nat. Pro.) | Rev. | Reac. |
---|---|---|---|---|---|---|
ATP + choline | Homo sapiens | - |
ADP + phosphocholine | - |
? |
Organism | UniProt | Comment | Textmining |
---|---|---|---|
Homo sapiens | P35790 | - |
- |
Purification (Comment) | Organism |
---|---|
recombinant His-SUMO-tagged wild-type and mutant enzymes from Escherichia coli strain Rosetta (DE3)pLysS by nickel affinity chromatography, and dialysis, if necessary the tag is cleaved, followed by another nickel affinity chromatography step, and dialysis, the last step for all is gel filtration | Homo sapiens |
Reaction | Comment | Organism | Reaction ID |
---|---|---|---|
ATP + choline = ADP + phosphocholine | reaction mechanism of choline kinase alpha, overview | Homo sapiens |
Source Tissue | Comment | Organism | Textmining |
---|---|---|---|
breast cancer cell | - |
Homo sapiens | - |
carcinoma cell | ChoKalpha1 is upregulated in many tumor types, including breast, lung, colorectal, and prostate cancers | Homo sapiens | - |
colorectal cancer cell | - |
Homo sapiens | - |
lung cancer cell | - |
Homo sapiens | - |
prostate gland cancer cell | - |
Homo sapiens | - |
Substrates | Comment Substrates | Organism | Products | Comment (Products) | Rev. | Reac. |
---|---|---|---|---|---|---|
ATP + choline | - |
Homo sapiens | ADP + phosphocholine | - |
? | |
ATP + choline | transfer of the gamma-phosphoryl group of ATP | Homo sapiens | ADP + phosphocholine | - |
? | |
additional information | usage of a coupled assay method with pyruvate kinase, and lactate dehydrogenase, at pH 7.5 and 37°C | Homo sapiens | ? | - |
- |
Subunits | Comment | Organism |
---|---|---|
homodimer | ChoKalpha1 forms a functional dimer, crystal structure analysis | Homo sapiens |
Synonyms | Comment | Organism |
---|---|---|
ChoKalpha | - |
Homo sapiens |
CHOKalpha1 | - |
Homo sapiens |
choline kinase alpha | - |
Homo sapiens |
Temperature Optimum [°C] | Temperature Optimum Maximum [°C] | Comment | Organism |
---|---|---|---|
37 | - |
assay at | Homo sapiens |
Turnover Number Minimum [1/s] | Turnover Number Maximum [1/s] | Substrate | Comment | Organism | Structure |
---|---|---|---|---|---|
19.5 | - |
choline | mutant enzyme ChoKalphaDELTA79, pH 7.5, 37°C | Homo sapiens | |
21.3 | - |
choline | mutant enzyme ChoKalphaDELTA49, pH 7.5, 37°C | Homo sapiens |
pH Optimum Minimum | pH Optimum Maximum | Comment | Organism |
---|---|---|---|
7.5 | - |
assay at | Homo sapiens |
General Information | Comment | Organism |
---|---|---|
evolution | choline kinase exists as two isoforms, alpha (ChoKalpha1 and 2) and beta. The alpha and beta isoforms are structurally similar and have sequence identity of 59%. The alpha isoform has a longer N-terminal sequence that shares no identity with the beta isoform, it also has a splice variant where residues 155-172 are missing (denoted ChoKalpha2), the unspliced variant, ChoKalpha1, has 457 residues | Homo sapiens |
malfunction | increased cellular pCho levels lead to increased cellular proliferation. Other downstream products of the Kennedy pathway include phosphatidylcholine, which stimulates growth factor-induced DNA synthesis, and glycerophosphocholine, which is incorporated into cell membranes and is necessary for cell proliferation | Homo sapiens |
additional information | ChoKALpha1DELTA49 binding to c-Src-SH3 requires an intact polyproline sequence preceding PL repeats motif but not ChoK kinase activity, two-state induced-fit model, binding analysis with ligand VSL12 (PDB ID 1QWF), overview | Homo sapiens |
physiological function | choline kinase is linked to cancer malignancy and poor patient prognosis. It is the first enzyme in the Kennedy pathway, ultimately leading to the production of phosphatidylcholine, a key component of biological membranes. Choline kinase exists as two isoforms, alpha (ChoKalpha1 and 2) and beta. Choline kinase alpha also has a non-catalytic protein-binding role and a function in protein-protein interactions. Choline kinase alpha interacts with the SH3 domain of c-Src. This interaction is specific and is mediated by the poly-proline region found N-terminal to the catalytic domain of choline kinase, importance of ChoKalpha1 residues 49-79 for the interaction with the SH3 domain of c-Src. ChoKalpha1 may serve both scaffolding and signaling functions in the context of this oncogenic pathway. The interaction between ChoKalpha1 and the c-Src SH3 domain does not impact the choline kinase enzymatic activity, kinetic analysis, overview. Protein-protein interaction has no influence on enzymatic activity per se | Homo sapiens |