Alternatively spliced forms of the cGMP-gated channel in human keratinocytes.

Alternatively spliced forms of the alpha subunit of the cGMP-gated channel have been cloned from human keratinocytes. One form encodes a complete channel which is almost identical to the rod photoreceptor. A second spliced variant would encode a protein missing a portion of the intracellular hydrophilic domain and the putative first transmembrane domain. Both complete and spliced variants of the channel also were found in epidermis. The expression of the complete form of the channel was induced by levels of extracellular calcium which promote keratinocyte differentiation. The cGMP-gated channel may play an important role in calcium induced keratinocyte differentiation by mediating Ca2+ entry.