Highly complex peptide aggregates of the S100 fused-type protein hornerin are present in human skin

Research output: Contribution to journalArticlepeer-review

  • External authors:
  • Zhihong Wu
  • Ulf Meyer-Hoffert
  • Katrin Reithmayer
  • Britta Hansmann
  • Yinghong He
  • Joachim Bartels
  • Regine Gläser
  • Jürgen Harder
  • Jens Michael Schröder


Human hornerin (HRNR) is a 245kDa S100 fused-type protein which contains 95 tandem quasi-repeating glycine- and serine-rich domains. Previously HRNR was not thought to be expressed in healthy skin; however, we purified an HRNR peptide fragment from stratum corneum. Moreover, we found that HRNR mRNA is expressed in skin biopsies from different sites as head, trunk, legs, hands, and feet. In cultured human epidermal keratinocytes, HRNR mRNA expression was transiently induced during Ca2-dependent differentiation. Immunostaining using distinct antibodies generated against four putative HRNR domains revealed strong HRNR immunoreactivity in healthy epidermis as well as in the entire outer root sheath of normal human scalp hair follicles. In lesions from psoriasis and atopic dermatitis patients, HRNR immunoreactivity was reduced compared with uninvolved skin of these patients. Electrospray ionization mass spectrometry and Western blot analyses revealed that HRNR is a highly degradable protein that forms complex high molecular weight peptide aggregates. Our findings suggest that HRNR is expressed in healthy skin and give insight into the complex biology of this protein. HRNR and its degradation products might contribute to the barrier function of healthy human skin.

Bibliographical metadata

Original languageEnglish
Pages (from-to)1446-1458
Number of pages12
JournalJournal of Investigative Dermatology
Issue number6
Publication statusPublished - Jun 2009