Ca2(+)-dependent interaction of N-copine, a member of the two C2 domain protein family, with OS-9, the product of a gene frequently amplified in osteosarcoma.
N-copine is a novel two C2 domain protein that shows Ca2(+)-dependent phospholipid binding and membrane association. By using yeast two-hybrid assays, we identified OS-9 as a protein capable of interacting with N-copine. We further revealed that the second C2 domain of N-copine bound with the carboxy-terminal region of OS-9. Their interaction in vivo was also confirmed by co-immunoprecipitation from 293E cells co-expressing transfected N-copine and OS-9. In vitro binding assays showed that this interaction was Ca2(+)-dependent. By Northern blot analysis, N-copine and OS-9 were co-expressed in the same regions of human brain. These results reveal that OS-9 is a potential target of N-copine.
Department of Bacteriology, Kinki University School of Medicine, Osaka-Sayama, Osaka, Japan. nakayama@med.kindai.ac.jp
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Nakayama
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Yaoi
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Kuwajima
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Yoshie
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Sakata
D001665:Binding Sites; D001923:Brain Chemistry; D002118:Calcium / Q000378:metabolism*; D002352:Carrier Proteins / Q000235:genetics / Q000302:isolation & purification / Q000378:metabolism*; D003001:Cloning, Molecular; D005784:Gene Amplification; D006801:Humans; D037102:Lectins; D009363:Neoplasm Proteins / Q000235:genetics / Q000302:isolation & purification / Q000378:metabolism*; D012516:Osteosarcoma; D011485:Protein Binding; D012441:Saccharomyces cerevisiae / Q000235:genetics; D014018:Tissue Distribution
D002352:Carrier Proteins; D037102:Lectins; D009363:Neoplasm Proteins; C098898:OS9 protein, human; C110203:copine; D002118:Calcium