A truncated splice variant of KCNQ1 cloned from rat heart.
KCNQ1 encodes a pore-forming subunit of potassium channels. Mutations in this gene cause inherited diseases, i.e., Romano-Ward syndrome and Jervell and Lange-Nielsen syndrome. A truncated isoform of KCNQ1 was reported to be expressed physiologically and to suppress a delayed rectifier potassium current dominant-negatively in human heart. However, it is not known whether this way of modulation occurs in other species. We cloned another truncated splice variant of KCNQ1 (tr-rKCNQ1) from rat heart. Judging from the deleted sequence of the tr-rKCNQ1, the genomic structure of rat in this portion might be different from those of human and mouse. Otherwise, an unknown exon might exist. RT-PCR analysis demonstrated that the tr-rKCNQ1 was expressed in fetal and neonatal hearts. When this gene was expressed along with a full-length KCNQ1, it suppressed potassium currents, whether a regulatory subunit minK was co-expressed or not.
Yamada
Yoichi
Y
Department of Cellular Physiology and Signal Transduction, Sapporo Medical University School of Medicine, Sapporo 060-8556, Japan. yamaday@sapmed.ac.jp
Chen
Xiangdong
X
Kobayashi
Takeshi
T
Kamada
Yasuhiro
Y
Nagashima
Masato
M
Tsutsuura
Masaaki
M
Seki
Sumihiko
S
Yamakage
Michiaki
M
Namiki
Akiyoshi
A
Tohse
Noritsugu
N
D000375:Aging; D017398:Alternative Splicing / Q000235:genetics*; D000818:Animals; D000831:Animals, Newborn; D015152:Blotting, Northern; D003001:Cloning, Molecular; D015870:Gene Expression; D006321:Heart / Q000196:embryology; D006801:Humans; D066298:In Vitro Techniques; D051656:KCNQ Potassium Channels; D051657:KCNQ1 Potassium Channel; D051379:Mice; D008845:Microinjections; D008969:Molecular Sequence Data; D009206:Myocardium / Q000378:metabolism*; D009865:Oocytes / Q000378:metabolism; D018408:Patch-Clamp Techniques; D011188:Potassium / Q000378:metabolism; D015221:Potassium Channels / Q000096:biosynthesis* / Q000235:genetics*; D024642:Potassium Channels, Voltage-Gated; D018075:RNA, Complementary / Q000008:administration & dosage / Q000378:metabolism; D051381:Rats; D020133:Reverse Transcriptase Polymerase Chain Reaction; D016415:Sequence Alignment; D017384:Sequence Deletion; D017386:Sequence Homology, Amino Acid; D014981:Xenopus
D051656:KCNQ Potassium Channels; D051657:KCNQ1 Potassium Channel; C496909:KCNQ1 protein, human; C496910:Kcnq1 protein, mouse; C496911:Kcnq1 protein, rat; D015221:Potassium Channels; D024642:Potassium Channels, Voltage-Gated; D018075:RNA, Complementary; C059983:potassium channel protein I(sk); D011188:Potassium