Identification and purification of Ca2+/calmodulin-dependent protein kinase V from human gastric carcinoma.
We previously purified a novel Ca2+/calmodulin-dependent protein kinase (CaM kinase) V, which has proven to be a member of the CaM kinase I family. Immunohistochemical staining of surgically-resected specimens from human subjects using specific antibody which reacts with CaM kinases I and V demonstrated heterogeneous distribution of CaM kinase I/V in normal gastric mucosa. The kinase was located mainly at the bottom of foveoral epithelium and in the gastric gland (< 25% immunopositive). In contrast, this kinase was abundant in various types of gastric carcinomas (> 75%), but not in gastric adenomas. Preferential and consistent presence of this kinase was confirmed by immunoblot analysis of gastric carcinoma and human gastric cancer cell lines, Kato-III and MKN-45. CaM kinase I/V was co-purified with CaM kinase II from resected gastric carcinoma using anion-exchange chromatography followed by calmodulin-affinity chromatography. The two kinases were finally separated by HPLC-based gel filtration. Purified CaM kinase I/V from gastric carcinoma did not possess detectable autophosphorylating activity, in contrast to CaM kinase II. The findings suggest CaM kinase I/V may possess abnormal biochemical properties in human gastric carcinoma, and the kinase could participate in cell growth of the carcinoma.
Ohta
H
H
Department of Pharmacology, Nagoya University School of Medicine, Japan.
Niki
I
I
Ito
T
T
Kato
M
M
Nimura
Y
Y
Usuda
N
N
Hidaka
H
H
D000230:Adenocarcinoma / Q000201:enzymology* / Q000473:pathology; D015153:Blotting, Western; D017871:Calcium-Calmodulin-Dependent Protein Kinases / Q000302:isolation & purification* / Q000378:metabolism; D002454:Cell Differentiation; D005753:Gastric Mucosa / Q000201:enzymology; D006801:Humans; D007124:Immunoenzyme Techniques; D008970:Molecular Weight; D010766:Phosphorylation; D013274:Stomach Neoplasms / Q000201:enzymology* / Q000473:pathology; D014407:Tumor Cells, Cultured / Q000201:enzymology
D017871:Calcium-Calmodulin-Dependent Protein Kinases; C088320:calmodulin-dependent protein kinase V