High impact information on Ckb

• The brain creatine kinase (BCK) promoter is responsive to estrogen but contains no ERE-related sequence [1].
• In vitro and in vivo promoter analyses of the human BCK gene identified an element between +25 and +57 that functioned as an enhancer [2].
• In large cells within the olfactory neuroepithelium and ventral spinal cord, differential compartmentation of CK isoforms was evident, with BCK localized primarily in cell nuclei, whereas uMtCK immunoreactivity was present in the cell body (but not within nuclei) [3].
• In embryonic skeletal and cardiac muscle, which also express BCK, the same compartmentation of BCK was seen, with BCK localized primarily in the cell nucleus of cardiac and skeletal myoblasts [3].
• These results demonstrate a coordinate pattern of expression and compartmentation of BCK and uMtCK isoforms in neurons, which provides an anatomic basis for the transfer of metabolic energy via a creatine phosphate energy shuttle [4].

Biological context of Ckb

• To ascertain whether the high nuclear B-CK in proliferating astrocytes correlated with ongoing cell division, we conducted experiments with confluent, nondividing cultures [5].
• Thus, beta-adrenergic stimulation induces a switch in CK gene expression from M-CK to B-CK, which is characteristic for the hypertrophied and failing heart [6].
• Both BCK and uMtCK mRNA expressions are strongly induced in placenta at 20 days gestation with a rapid fall (> 6-fold) immediately before delivery [7].
• Creatine kinase (CK) is important for energy transfer and is composed of mitochondrial (mitCK), muscle (MCK), and brain (BCK) subunits, each being the product of separate nuclear genes [8].

Anatomical context of Ckb

• The localization of CK isoforms was examined by immunocytochemistry, and, during the fetal period, BCK and uMtCK immunoreactivity was detected throughout the central and peripheral nervous system, especially in neuroepithelial regions of the cerebral vesicles and spinal cord [3].
• BCK immunostaining is also present in somata of Golgi type I neurons in the cerebellum, red nucleus, and pons and is distributed throughout the cell body and within nuclei [4].
• BCK immunostaining also appears in neuronal processes and is concentrated in the molecular layers of the cerebellum and the hippocampus and in cortical pyramidal cell dendrites [4].
• We found that low density, dividing astrocyte cultures also exhibited high B-CK (brain isoenzyme of CK) immunoreactivity, with the nuclear CK staining being especially intense [5].
• Gastrocnemius muscle from treadmill trained rats was analyzed for creatine kinase (CK) isoenzyme activities by agarose electrophoresis and M and B CK mRNA levels by Northern blot analysis [9].

Associations of Ckb with chemical compounds

• The second linkage group is comprised of one gene, Ckb (creatine kinase, brain) and one anonymous DNA locus, D6Arb54, separated by 4.0 cM [10].
• By ammonium sulfate cut and gel filtration, affinity and ion exchange chromatographies, the immunoreactive protein was purified to homogeneity and identified as brain-type creatine kinase (B-CK) [11].

Analytical, diagnostic and therapeutic context of Ckb

• Immunoblotting experiments with the cytoplasmic and mitochondrial fractions of rat heart, brain and liver, as well as inactivation studies with the purified chicken CK isoenzymes have further demonstrated that all four CK isoenzymes (Mia-, Mib-, M- and B-CK) are indeed selectively labelled by BrAcT3 [12].
• Two isoforms of CK are present in brain extracts, "brain-type," or BCK, and the ubiquitous form of the mitochondrial CK (uMtCK), as detected by enzyme activity following nondenaturing electrophoresis and by Western blotting following denaturing electrophoresis [4].
• After beta-adrenergic stimulation (iso 3 h) but not after control perfusion (control 3 h) a roughly threefold increase in B-CK mRNA levels and a decrease in M-CK mRNA levels by 18% was found [6].
• Left ventricular tissue was analyzed for total CK-activity, CK-isoenzyme distribution and, by use of quantitative RT-PCR, for B-CK, M-CK, mito-CK and GAPDH- (as internal standard) mRNA [6].

References