Cloning of a pH-sensitive K+ channel possessing two transmembrane segments.
The mammalian renal collecting ducts are responsible for secreting potassium ions into the urine and are a major regulatory site for potassium homeostasis, in which a voltage-independent pH-sensitive K+ channel in the apical membrane plays a central role. Here we describe a complementary DNA encoding a novel K+ channel from rabbit renal cortical collecting tubule cells (RACTK1). RACTK1 has the functional characteristics of the apical K(+)-permeable channel and consists of 284 amino acids, putatively with two transmembrane segments. The sequence of RACTK1, however, shows no homology to known voltage-dependent or -independent K+ channels, and has a different K(+)-driving path and regulatory sites. The study of this protein should provide insight into K+ homeostasis and diseases of K+ metabolism.
Suzuki
M
M
Department of Pharmacology, Jichi Medical School, Tochigi, Japan.
Takahashi
K
K
Ikeda
M
M
Hayakawa
H
H
Ogawa
A
A
Kawaguchi
Y
Y
Sakai
O
O
D000595:Amino Acid Sequence; D000818:Animals; D001483:Base Sequence; D016466:CHO Cells; D003001:Cloning, Molecular; D006224:Cricetinae; D003412:Cricetulus; D018076:DNA, Complementary; D006863:Hydrogen-Ion Concentration; D015640:Ion Channel Gating; D007685:Kidney Tubules, Collecting / Q000737:chemistry* / Q000502:physiology; D008969:Molecular Sequence Data; D015221:Potassium Channels / Q000737:chemistry* / Q000235:genetics / Q000502:physiology; D011817:Rabbits; D017386:Sequence Homology, Amino Acid
D018076:DNA, Complementary; D015221:Potassium Channels; C085904:RACTK1 protein, Oryctolagus cuniculus