Molecular cloning and characterization of a novel calcium/calmodulin-dependent protein kinase II inhibitor from human dendritic cells.
Calcium/calmodulin-dependent protein kinase II (CaMKII) is a widely distributed protein kinase that regulates numerous physiological functions. Inhibitors of CaMKII are useful tools for investigating the CaMKII functions. Here we identified a novel CaMKII inhibitor protein (CaM-KIIN) from the human dendritic cell cDNA library by large-scale random sequencing. Human CaM-KIIN contains 79 amino acids, which shares 98% identity and 98% positives with rat CaMKII inhibitor protein beta and 65% identity and 78% positives with rat CaMKII inhibitor alpha. Human CaM-KIIN mRNA expression was detectable in various tissues and cell lines by Northern blot and RT-PCR. To investigate its biological functions, full-length human CaM-KIIN was overexpressed in colon adenocarcinoma LoVo cells. When expressed in LoVo cells, it could inhibit cell proliferation, block cell growth, and decrease the viable cell number. These results characterize a potential cellular inhibitor protein of CaMKII that plays an important role in the regulation of cell growth.
Zhang
J
J
Department of Clinical Laboratory, Changzheng Hospital, Shanghai 200003, People's Republic of China.
Li
N
N
Yu
J
J
Zhang
W
W
Cao
X
X
D000230:Adenocarcinoma; D000595:Amino Acid Sequence; D000818:Animals; D017871:Calcium-Calmodulin-Dependent Protein Kinases / Q000037:antagonists & inhibitors; D002352:Carrier Proteins / Q000737:chemistry* / Q000235:genetics* / Q000502:physiology; D002455:Cell Division; D003001:Cloning, Molecular; D003110:Colonic Neoplasms; D003713:Dendritic Cells / Q000378:metabolism*; D004791:Enzyme Inhibitors / Q000737:chemistry / Q000494:pharmacology; D005260:Female; D015723:Gene Library; D006367:HeLa Cells; D006801:Humans; D047908:Intracellular Signaling Peptides and Proteins; D007700:Kinetics; D008969:Molecular Sequence Data; D009928:Organ Specificity; D012333:RNA, Messenger / Q000032:analysis / Q000235:genetics; D051381:Rats; D011994:Recombinant Proteins / Q000737:chemistry / Q000378:metabolism; D020133:Reverse Transcriptase Polymerase Chain Reaction; D016415:Sequence Alignment; D017386:Sequence Homology, Amino Acid; D014158:Transcription, Genetic; D014162:Transfection; D014407:Tumor Cells, Cultured
C114422:CAMK2N2 protein, human; D002352:Carrier Proteins; D004791:Enzyme Inhibitors; D047908:Intracellular Signaling Peptides and Proteins; D012333:RNA, Messenger; D011994:Recombinant Proteins; D017871:Calcium-Calmodulin-Dependent Protein Kinases