Koebnerisin (S100A15) is a protein that in humans is encoded by the S100A15 (alias:S100A7A) gene[1].
S100 proteins are a diverse calcium-binding family that regulate fundamental cellular and extracellular processes including cell proliferation and differentiation, cell migration, and the antimicrobial host defense as antimicrobial peptides.
Koebnerisin (S100A15) was first identified upregulated in inflammation-prone psoriatic skin, suggesting involvement in the lesional phenotype of the disease[2], Koebner phenomenon. Today, the protein is of further interest because of its role in antimicrobial defence, innate immunity, epidermal cell maturation and epithelial tumorigenesis [3].
Function
editEpithelial homeostasis and antimicrobial host defence
editSkin: In normal epidermis, koebnerisin (S100A15) is expressed by epidermal basal and differentiated keratinocytes, melanocytes, and Langerhans cells. Within the pilosebaceous unit, S100A15 is found in the inner and external root sheath and the basal layer of the sebaceous gland. In the dermis, koebnerisin (S100A15) is produced by dendritic cells smooth muscle cells and endothelial cells[4].
Breast: Koebnerisin (S100A15) is expressed by alveolar and small duct luminal cells and by epithelial-derived myoepithelial cells around acini and by surrounding blood vessels[5]. Koebnerisin (S100A15) functions as an antimicrobial peptide (AMP) reducing survival of E. coli and was strongly regulated by several bacterial components, such as P. aeruginosa and S. aureus. Thus, koebnerisin participates in the antimicrobial host defence of the skin and in the digestive tract of breast-feeding newborns[6].
Epithelial Carcinogenesis
editBreast cancer: Koebnerisin (S100A15) is overexpressed in ER/PR negative tumors suggesting a regulation with tumor progression[7]. The secreted koebnerisin (S100A15) acts as a chemoattractant[8], enhances inflammation and thus could drive breast carcinogenesis.
Inflammation
editKoebnerisin (S100A15) is overexpressed in inflammatory skin diseases, such as psoriasis and eczema. It is regulated through Th1 but not Th2 proinflammatory cytokines[9]. When released into the extracellar space, koebnerisin (S100A15) induces inflammation. It acts as a chemoattractant for lymphocytes and myeloid leukocytes through a pertussis toxin sensitive Gi protein coupled receptor. Koebnerisin (S100A15) amplifies inflammation with related psoriasin (S100A7) that is co-regulated and proinflammatory through RAGE.
Special characteristics
editGenomic organization and mRNA splice variants
editKoebnerisin (S100A15) maps to the S100 gene cluster within the epidermal differentiation complex (EDC, chromosome 1q21) and reveals an unusual genomic organization compared to other S100 members. The two alternative mRNA-isoforms of koebnerisin share the same coding region, but show differences in composition and length of adjacent untranslated regions (S100A15-short (S): 0.5 kb vs. hS100A15-long (L): 4.4 kb). Both splice variants are differently regulated in inflammatory skin diseases suggesting usage of alternate promoters [10][11].
Protein
editThe amino acid sequence reveals a conserved C-terminal and a variant N-terminal EF-hand typical for S100 proteins (101 amino acids, 11.305 Da, calculated pI of 7.57 kDa). Compared to most S100 proteins, koebnerisin (S100A15) is basic.
Evolution
editprimate
editKoebnerisin (S100A15) has lately evolved by gene duplications within the Epidermal Differentiation Complex (EDC, chromosome 1q21) during primate evolution forming a novel S100 subfamily together with Psoriasin (S100A7)[12][13]. Therefore, koebnerisin is almost identical to psoriasin in sequence (>90%). Despite their high homology, koebnerisin (S100A15) and psoriasin (S100A7) are distinct in tissue distribution, regulation, and function and, thus exemplary for the diversity within the S100 family. Their different properties are compelling reasons to discriminate S100A15 (koebnerisin) and S100A7 (psoriasin) in epithelial homeostasis, inflammation and cancer.
rodent
editKoebnerisin (S100A15) and psoriasin (S100A7) share a common protein in mice encoded by the S100a7a15 (alias: mS100A7, mS100A15, mS100a7a) gene[14]. It can be used to study the significance of the corresponding human proteins for inflammation[15].
References
edit- ^ http://www.ncbi.nlm.nih.gov/gene/338324
- ^ R. Wolf, A. Mirmohammadsadegh, M. Walz, B. Lysa, U. Tartler, R. Remus, U. Hengge, G. Michel, and T. Ruzicka: Molecular Cloning and Characterization of Alternatively Spliced mRNA-Isoforms from Psoriatic Skin Encoding a Novel Member of the S100 Family. FASEB J. 17.1969-71. (2003)
- ^ R. Wolf, T. Ruzicka, and S.H. Yuspa: Novel S100A7 (psoriasin)/ S100A15 (koebnerisin) subfamily - highly homologous but distinct in regulation and function. Amino Acids. Jul 2. (2010, online)
- ^ R. Wolf, O. M. Zack Howard, H.F. Dong, C. Voscopoulos, K. Boeshans, J. Winston, R. Divi, M. Gunsior, P. Goldsmith, B. Ahvazi, T. Chavakis, J. J. Oppenheim, and S. H. Yuspa: Chemotactic Activity of S100A7 (Psoriasin) Is Mediated by the Receptor for Advanced Glycation End Products (RAGE) and Potentiates Inflammation with Highly Homologous but Functionally Distinct S100A15. J. Immunol. 181. 1507-1518 (2008)
- ^ R. Wolf, C. Voscopoulos, J. Winston, A. Dharamsi, P. Goldsmith, M. Gunsior, B. K. Vonderhaar, M. Olson, P.H. Watson, and S. H. Yuspa: Highly homologous hS100A15 and hS100A7 proteins are distinctly expressed in normal breast tissue and breast cancer. Cancer Lett. 277.101-107 (2009)
- ^ A.S. Büchau, M. Hassan, G. Kukova, V. Lewerenz, S. Kellermann, J.U. Wurthner, R. Wolf, M. Walz, R.L. Gallo, and T. Ruzicka: S100A15 - a new antimicrobial protein of the skin: Regulation by Escherichia coli through Toll-like receptor 4. J. Invest. Dermatol.127. 2596-604 (2007)
- ^ R. Wolf, C. Voscopoulos, J. Winston, A. Dharamsi, P. Goldsmith, M. Gunsior, B. K. Vonderhaar, M. Olson, P.H. Watson, and S. H. Yuspa: Highly homologous hS100A15 and hS100A7 proteins are distinctly expressed in normal breast tissue and breast cancer. Cancer Lett. 277.101-107 (2009)
- ^ R. Wolf, O. M. Zack Howard, H.F. Dong, C. Voscopoulos, K. Boeshans, J. Winston, R. Divi, M. Gunsior, P. Goldsmith, B. Ahvazi, T. Chavakis, J. J. Oppenheim, and S. H. Yuspa: Chemotactic Activity of S100A7 (Psoriasin) Is Mediated by the Receptor for Advanced Glycation End Products (RAGE) and Potentiates Inflammation with Highly Homologous but Functionally Distinct S100A15. J. Immunol. 181. 1507-1518 (2008)
- ^ R. Wolf, V. Lewerenz, A.S. Büchau, M. Walz, and T. Ruzicka: Human S100A15 splice variants are differentially expressed in inflammatory skin diseases and regulated through Th1-cytokines and calcium. Exp. Dermatol. 16.685-91 (2007)
- ^ R. Wolf, A. Mirmohammadsadegh, M. Walz, B. Lysa, U. Tartler, R. Remus, U. Hengge, G. Michel, and T. Ruzicka: Molecular Cloning and Characterization of Alternatively Spliced mRNA-Isoforms from Psoriatic Skin Encoding a Novel Member of the S100 Family. FASEB J. 17.1969-71. (2003)
- ^ R. Wolf, V. Lewerenz, A.S. Büchau, M. Walz, and T. Ruzicka: Human S100A15 splice variants are differentially expressed in inflammatory skin diseases and regulated through Th1-cytokines and calcium. Exp. Dermatol. 16.685-91 (2007)
- ^ Kulski JK, Lim CP, Dunn DS, Bellgard M.: Genomic and phylogenetic analysis of the S100A7 (Psoriasin) gene duplications within the region of the S100 gene cluster on human chromosome 1q21.J Mol Evol. 2003 Apr;56(4):397-406.
- ^ R. Wolf, C.J. Voscopoulos, P.C. FitzGerald, P. Goldsmith, C. Cataisson, M. Gunsior, M. Walz, T. Ruzicka, and S.H. Yuspa: The mouse S100A15 ortholog parallels genomic organization, structure, gene expression, and protein-processing pattern of the human S100A7/A15 subfamily during epidermal maturation. J. Invest. Dermatol.126. 1600-1608 (2006)
- ^ http://www.ncbi.nlm.nih.gov/gene/381493
- ^ R. Wolf, C.J. Voscopoulos, P.C. FitzGerald, P. Goldsmith, C. Cataisson, M. Gunsior, M. Walz, T. Ruzicka, and S.H. Yuspa: The mouse S100A15 ortholog parallels genomic organization, structure, gene expression, and protein-processing pattern of the human S100A7/A15 subfamily during epidermal maturation. J. Invest. Dermatol.126. 1600-1608 (2006)