title: Isolation and characterization of human repetin, a member of the fused gene family of the epidermal differentiation complex.
abstract: The human repetin gene is a member of the "fused" gene family and localized in the epidermal differentiation complex on chromosome 1q21. The "fused" gene family comprises profilaggrin, trichohyalin, repetin, hornerin, the profilaggrin-related protein and a protein encoded by c1orf10. Functionally, these proteins are associated with keratin intermediate filaments and partially crosslinked to the cell envelope (CE). Here, we report the isolation and characterization of the human repetin gene and of its protein product. The repetin protein of 784 amino acids contains EF (a structure resembling the E helix-calcium-binding loop-F helix domain of parvalbumin) hands of the S100 type and internal tandem repeats typical for CE precursor proteins, a combination which is characteristic for "fused" proteins. Repetin expression is scattered in the normal epidermis but strong in the acrosyringium, the inner hair root sheat and in the filiform papilli of the tongue. Ultrastructurally, repetin is a component of cytoplasmic non-membrane "keratohyalin" F-granules in the stratum granulosum of normal epidermis, similar to profilaggrin. Finally, we show that EF hands are functional and reversibly bind Ca(2+). Our results indicate that repetin is indeed a member of the fused gene family similar to the prototypical members profilaggrin and trichohyalin.
authors.affiliation: Department of Dermatology, University Hospital of Lausanne, Lausanne, Switzerland.
authors.forename: Marcel
authors.initials: M
authors.lastname: Huber
authors.forename: Georges
authors.initials: G
authors.lastname: Siegenthaler
authors.forename: Nicolae
authors.initials: N
authors.lastname: Mirancea
authors.forename: Ingo
authors.initials: I
authors.lastname: Marenholz
authors.forename: Dean
authors.initials: D
authors.lastname: Nizetic
authors.forename: Dirk
authors.initials: D
authors.lastname: Breitkreutz
authors.forename: Dietmar
authors.initials: D
authors.lastname: Mischke
authors.forename: Daniel
authors.initials: D
authors.lastname: Hohl
mesh_terms: D000595:Amino Acid Sequence; D001483:Base Sequence; D015415:Biomarkers; D002118:Calcium / Q000378:metabolism; D002454:Cell Differentiation; D002478:Cells, Cultured; D002874:Chromosome Mapping; D018076:DNA, Complementary / Q000737:chemistry; D000078404:Epidermal Cells; D006801:Humans; D008969:Molecular Sequence Data; D009418:S100 Proteins / Q000032:analysis / Q000737:chemistry / Q000235:genetics* / Q000378:metabolism
chemical_list: D015415:Biomarkers; D018076:DNA, Complementary; C108628:Rptn protein, mouse; D009418:S100 Proteins; D002118:Calcium