Molecular cloning of cyclic nucleotide-gated cation channel subunits from rat pineal gland.

We have investigated the subunit composition and the molecular structure of the CNG channel expressed in rat pineal gland. Three types of subunits have been cloned: an alpha-subunit (CNG1), two beta-subunit splice variants (rCNG4.1 and rCNG4.2) and a hydrophilic glutamic acid-rich protein (rGARP). In situ hybridization with sections of rat brain revealed the co-expression of CNG1, CNG4 and GARP in pinealocytes. In addition, CNG4-specific transcripts were detected in the arcuate, periventricular and supraoptic nuclei of the hypothalamus.