Molecular cloning of the human volume-sensitive chloride conductance regulatory protein, pICln, from ocular ciliary epithelium.
Chloride channels in the ocular ciliary epithelium are believed to play a key role in aqueous humor formation. We isolated a cDNA clone from a lambda Uni-ZAP cDNA library of human nonpigmented ciliary epithelial (NPE) cells encoding the swelling-induced chloride channel/channel regulator pICln. The human clone contains an open reading frame of 237 amino acids (M(r) 26,293). The deduced human amino-acid sequence shows 90.2% and 92.7% identity with counterparts isolated from rat kidney and the canine kidney epithelial cell line MDCK. Human NPE cell lines exhibited significant levels of pICln transcripts. Complementary perforated-patch, whole-cell patch clamping demonstrated that swelling activates Cl- channels of the NPE cells, as suggested by ruptured-patch measurements. The results document the molecular isolation and identification of a human cDNA clone of a Cl- conductance regulator from ocular cells displaying volume-activated Cl-channels.
Anguita
J
J
Department of Ophthalmology, Yale University School of Medicine, New Haven, CT.
Chalfant
M L
ML
Civan
M M
MM
Coca-Prados
M
M
D000595:Amino Acid Sequence; D000818:Animals; D001082:Aqueous Humor / Q000502:physiology; D001483:Base Sequence; D002460:Cell Line; D018118:Chloride Channels / Q000096:biosynthesis* / Q000502:physiology; D002712:Chlorides / Q000494:pharmacology; D002924:Ciliary Body / Q000378:metabolism*; D003001:Cloning, Molecular; D004285:Dogs; D004848:Epithelium / Q000378:metabolism; D015870:Gene Expression; D015723:Gene Library; D006801:Humans; D007473:Ion Channels; D007668:Kidney; D008969:Molecular Sequence Data; D016366:Open Reading Frames; D018408:Patch-Clamp Techniques; D051381:Rats; D011994:Recombinant Proteins / Q000096:biosynthesis; D015183:Restriction Mapping; D017386:Sequence Homology, Amino Acid
C410035:CLNS1A protein, human; D018118:Chloride Channels; D002712:Chlorides; C498729:Clns1a protein, rat; D007473:Ion Channels; D011994:Recombinant Proteins