Repetin (RPTN)

The deduced 784-amino acid protein has a calculated molecular mass of 91 kD. RPTN contains 2 N-terminal EF hand motifs, a central domain containing 28 repeats of the consensus sequence QxDRQGQSSHYG, and a glutamine- and arginine-rich C-terminal domain. Northern blot analysis detected a 4-kb RPTN transcript in human thymus, epidermis, and foreskin and in keratinocyte suspension cultures. Very low expression was detected in adherent keratinocyte cultures, and none was detected in other tissues. Immunofluorescence analysis detected RPTN in the upper granular layer of human interfollicular epidermis, in acrosyringium, in the upper cell layers of foreskin epidermis, in a granular pattern in filiform papillae of tongue, in upper layer cells of lingual interpapillae, and in the inner root sheath of hair follicle.