Evidence for Na+/Ca2+ exchanger 1 association with caveolin-1 and -2 in C6 glioma cells.
The purpose of this study is to understand the interaction of Na + -Ca2+ exchanger (NCX1), that is one of the essential regulators of Ca2+ homeostasis, with caveolin (Cav)-1 and Cav-2 in Cav-3 null cell (rat C6 glioma cell). Both mRNA and protein expression of NCX1, Cav-1 and Cav-2 was observed, but no expression of mRNA and protein of Cav-3 were observed in C6 glioma cells. In isolated caveolae-enriched membrane fraction, the NCX1, Cav-1 and Cav-2 proteins localized in same fractions. The experiment of immuno-precipitation showed complex formation between the NCX1 and Cavs. Confocal microscopy also supported co-localization of NCX1and Cavs at the plasma membrane. Functionally, sodium-free induced forward mode of NCX1 attenuated by Cav-1 antisense ODN. When treated cells with Cav-2 antisense ODN, both reverse and forward mode of NCX1 was attenuated. From these results, in the Cav-3 lacking cells, the function of NCX1 might be regulated by binding with Cavs. Considering the decrement of NCX1 activity by antisense ODNs, caveolins may play an important role in diverse of pathophysiological process of NCX1-related disorders in the body.
Cha
Seok Ho
SH
Departments of Pharmacology and Toxicology, College of Medicine, Inha University, 253 Yonghyun-dong, Nam-gu, Incheon 402-751, Korea. shcha@inha.ac.kr
Shin
Sun Young
SY
Jung
Sang Yong
SY
Kim
Yun Tai
YT
Park
Yong Joo
YJ
Kwak
Jin-Oh
JO
Kim
Hyun-Woo
HW
Suh
Chang Kook
CK
D000818:Animals; D001665:Binding Sites; D015153:Blotting, Western; D002118:Calcium / Q000378:metabolism; D051242:Caveolin 1; D051243:Caveolin 2; D022461:Caveolins / Q000378:metabolism*; D045744:Cell Line, Tumor; D002462:Cell Membrane / Q000378:metabolism; D006801:Humans; D047468:Immunoprecipitation; D007477:Ions; D018613:Microscopy, Confocal; D016376:Oligonucleotides, Antisense / Q000494:pharmacology; D011485:Protein Binding; D012333:RNA, Messenger / Q000378:metabolism; D051381:Rats; D020133:Reverse Transcriptase Polymerase Chain Reaction; D012964:Sodium / Q000494:pharmacology; D019831:Sodium-Calcium Exchanger / Q000378:metabolism*; D013997:Time Factors
C495540:CAV1 protein, human; C495537:Cav1 protein, rat; D051242:Caveolin 1; D051243:Caveolin 2; D022461:Caveolins; D007477:Ions; D016376:Oligonucleotides, Antisense; D012333:RNA, Messenger; D019831:Sodium-Calcium Exchanger; C110374:sodium-calcium exchanger 1; D012964:Sodium; D002118:Calcium