Nomenclature
Short Name:
CKB
Full Name:
Creatine kinase B-type
Alias:
- B-CK
- CKBB
- Creatine kinase, B chain
- Creatine kinase, brain
- KCRB
Classification
Type:
Protein-serine/threonine kinase
Group:
Atypical
Family:
CK
SubFamily:
NA
Specific Links
Structure
Mol. Mass (Da):
42644
# Amino Acids:
381
# mRNA Isoforms:
1
mRNA Isoforms:
42,644 Da (381 AA; P12277)
4D Structure:
1D Structure:
3D Image (rendered using PV Viewer):
PDB ID
Subfamily Alignment
Domain Distribution:
| Start | End | Domain |
|---|
Post-translation Modifications
For detailed information on phosphorylation of this kinase go to PhosphoNET
Acetylated:
K267, K313.
Methylated:
R138.
Serine phosphorylated:
S4, S6, S24, S128, S136, S164, S178, S199, S285, S309, S337.
Threonine phosphorylated:
T35, T108, T133, T327.
Tyrosine phosphorylated:
Y39, Y82, Y125, Y173, Y174, Y269, Y279.
Ubiquitinated:
K11, K86, K223, K242, K265, K298, K304, K307, K313.
Distribution
Based on gene microarray analysis from the NCBI
Human Tissue Distribution
% Max Expression:
Mean Expression:
Number of Samples:
Standard Deviation:
% Max Expression:
Mean Expression:
Number of Samples:
Standard Deviation:
23
1096
16
996
8
376
12
249
16
777
1
0
44
2090
54
1302
16
741
14
722
5
221
43
303
34
1602
23
761
30
1428
28
1404
11
513
10
289
16
752
59
585
3
141
18
126
18
869
117
628
2
73
12
29
8
383
12
302
4
192
14
125
9
421
9
145
48
2283
190
1137
9
410
10
329
6
261
69
254
17
786
56
742
39
1861
14
1115
4
182
16
158
12
563
10
398
18
850
10
417
3
161
14
156
19
910
34
819
2
86
15
43
11
516
10
319
25
1182
10
813
7
339
14
175
10
473
18
328
21
977
21
2178
45
2119
54
2445
16
742
31
733
100
4724
20
5463
Evolution
Species Conservation
PhosphoNET % Identity:
PhosphoNET % Similarity:
Homologene %
Identity:
PhosphoNET % Identity:
PhosphoNET % Similarity:
Homologene %
Identity:
100
100
100
81.9
82.1
100
99.2
100
99
-
-
97
-
-
-
94.4
95.9
98
-
-
-
96.5
98.6
97
96.5
98.4
97
-
-
-
77.9
83.7
-
90.5
96.3
91
83.1
92.3
85
85.8
93.1
84
-
-
-
42.7
59
-
40.9
58.7
-
37.7
55.9
-
22.4
28.1
-
-
-
-
96.5
98.4
-
-
-
-
-
-
-
-
-
-
-
-
-
For a wider analysis go to PhosphoNET Evolution in PhosphoNET
Regulation
Activation:
NA
Inhibition:
NA
Synthesis:
NA
Degradation:
NA
Disease Linkage
General Disease Association:
Cancer, cardiovascular disorders
Specific Diseases (Non-cancerous):
Myocardial infarction; Brain ischemia
Specific Cancer Types:
Prostate rhabdomyosarcomas
Comments:
CKB may be a tumour requiring protein (TRP), since it displays extremely low rates of mutation in human cancers.
Gene Expression in Cancers:
TranscriptoNET (www.transcriptonet.ca) analysis with mRNA expression data retrieved from the National Center for Biotechnology Information's Gene Expression Omnibus (GEO) database, which was normalized against 60 abundantly and commonly found proteins, indicated altered expression for this protein kinase as shown here as the percent change from normal tissue controls (%CFC) as supported with the Student T-test in the following types of human cancers: Bladder carcinomas (%CFC= -45, p<0.028); Breast epithelial hyperplastic enlarged lobular units (HELU) (%CFC= -55, p<0.072); Cervical cancer stage 2B (%CFC= -59, p<0.049); Gastric cancer (%CFC= -72, p<0.029); Large B-cell lymphomas (%CFC= +47, p<0.007); Ovary adenocarcinomas (%CFC= +60, p<0.102); Papillary thyroid carcinomas (PTC) (%CFC= -51, p<0.019); Pituitary adenomas (ACTH-secreting) (%CFC= +255); Prostate cancer (%CFC= -61, p<0.019); and Skin melanomas (%CFC= -63, p<0.06). The COSMIC website notes an up-regulated expression score for CKB in diverse human cancers of 373, which is 0.8-fold of the average score of 462 for the human protein kinases. The down-regulated expression score of 2 for this protein kinase in human cancers was 97% lower than the average score of 60 for the human protein kinases.
Mutagenesis Experiments:
Insertional mutagenesis studies in mice have not yet revealed a role for this protein kinase in mouse cancer oncogenesis. Phosphotransferase activity can be abrogated with the C283S/Y or R292H/L/Q mutations, while partial blocking of activity can be obtained through a R292K mutation.
Mutation Rate in All Cancers:
Percent mutation rates per 100 amino acids length in human cancers: 0.03 % in 24548 diverse cancer specimens. This rate is -57 % lower than the average rate of 0.075 % calculated for human protein kinases in general. Such a low frequency of mutation in human cancers is consistent with this protein kinase playing a role as a tumour requiring protein (TRP).
Mutation Rate in Specific Cancers:
Highest percent mutation rates per 100 amino acids length in human cancers: 0.19 % in 555 stomach cancers tested; 0.12 % in 1270 large intestine cancers tested.
Frequency of Mutated Sites:
None > 2 in 19,805 cancer specimens
Comments:
Only 1 deletion, and no insertions or complex mutations are noted on the COSMIC website.