Molecular cloning and expression of the novel splice variants of K(+) channel-interacting protein 2.
Two cDNAs encoding the splice variants of K(+) channel-interacting protein 2 (KChIP2) recently reported as human KChIP2 have been identified from rat, mouse, and human heart by RT-PCR. A longer variant, KChIP2L encodes a protein of 270 amino acids, which has a 50-amino-acid insertion in N-terminus in comparison with a shorter one, KChIP2S. Interestingly, both KChIP2S and KChIP2L (KChIP2S/L) but not the original KChIP2 were expressed in human heart and umbilical vein endothelial cells (HUVECs). KChIP2S transcripts but not KChIP2L were predominantly expressed in rat, mouse, and human heart and HUVECs, whereas both transcripts were expressed at low levels in other tissues such as brain, aorta, and kidney. Using chimeric proteins of green fluorescence protein (GFP) fused to the N-terminus of KChIP2S/L, the interactions between Kv4.3 and KChIP2S/L were analyzed in native and Kv4.3-expressed HEK293 cells. Specific localization of GFP-fused KChIP2S/L proteins on or near cell membrane was observed only in Kv4.3-expressed HEK293 cells.
Ohya
S
S
Department of Molecular and Cellular Pharmacology, Faculty of Pharmaceutical Sciences, Nagoya City University, 3-1 Tanabedori, Mizuhoku, Nagoya, 467-8603, Japan.
Morohashi
Y
Y
Muraki
K
K
Tomita
T
T
Watanabe
M
M
Iwatsubo
T
T
Imaizumi
Y
Y
D000595:Amino Acid Sequence; D000818:Animals; D001483:Base Sequence; D002135:Calcium-Binding Proteins / Q000737:chemistry / Q000235:genetics* / Q000378:metabolism; D002478:Cells, Cultured; D003001:Cloning, Molecular; D017931:DNA Primers; D006801:Humans; D007150:Immunohistochemistry; D051605:Kv Channel-Interacting Proteins; D008297:Male; D008969:Molecular Sequence Data; D051381:Rats; D017208:Rats, Wistar; D020133:Reverse Transcriptase Polymerase Chain Reaction; D017386:Sequence Homology, Amino Acid
D002135:Calcium-Binding Proteins; D017931:DNA Primers; C496752:KCNIP2 protein, human; C496758:Kcnip2 protein, rat; D051605:Kv Channel-Interacting Proteins