CLONING AND FUNCTIONAL EXPRESSION OF A SWELLING-INDUCED CHLORIDE CONDUCTANCE REGULATORY PROTEIN, PL(CLN), FROM RABBIT OCULAR CILIARY EPITHELIUM

The cDNA encoding a swelling-induced chloride conductance regulatory p rotein, pl(cln), was cloned from rabbit ciliary epithelium by using a polymerase chain reaction (PCR)-based approach, The open reading frame encoding 236 amino acids possesses high amino acid identity (93/%) wi th the previously cloned pl(cln) from human ciliary epithelium. Outwar dly rectifying currents were recorded in Xenopus oocytes injected with pl(cln) cRNA, a result consistent with pl(cln) expression in ciliary epithelium. A widespread distribution and marked expression of pl(cln) mRNA in both nonpigmented ciliary epithelial (NPE) cells and pigmente d ciliary epithelial (PE) cells was found for the first time. In situ hybridization analysis skewed that pl(cln) expression is more abundant in NPE than PE. These findings are consistent with the idea that pl(c ln) may be an important regulatory element in these secretory cells. ( C) 1997 Academic Press.