title: Crystal Structure of Human Profilaggrin S100 Domain and Identification of Target Proteins Annexin II, Stratifin, and HSP27.
abstract: The fused-type S100 protein profilaggrin and its proteolytic products including filaggrin are important in the formation of a normal epidermal barrier; however, the specific function of the S100 calcium-binding domain in profilaggrin biology is poorly understood. To explore its molecular function, we determined a 2.2 Å-resolution crystal structure of the N-terminal fused-type S100 domain of human profilaggrin with bound calcium ions. The profilaggrin S100 domain formed a stable dimer, which contained two hydrophobic pockets that provide a molecular interface for protein interactions. Biochemical and molecular approaches demonstrated that three proteins, annexin II/p36, stratifin/14-3-3 sigma, and heat shock protein 27, bind to the N-terminal domain of human profilaggrin; one protein (stratifin) co-localized with profilaggrin in the differentiating granular cell layer of human skin. Together, these findings suggest a model where the profilaggrin N-terminus uses calcium-dependent and calcium-independent protein-protein interactions to regulate its involvement in keratinocyte terminal differentiation and incorporation into the cornified cell envelope.
authors.affiliation: Department of Dermatology, Yale University, New Haven, Connecticut, USA; Department of Molecular Biophysics and Biochemistry, Yale University, New Haven, Connecticut, USA; The first two authors contributed equally to this work.. Electronic address: christopher.bunick@yale.edu.
authors.forename: Christopher G
authors.initials: CG
authors.lastname: Bunick
authors.affiliation: Department of Oral Health Sciences, University of Washington, Seattle, Washington, USA; Department of Medicine, Division of Dermatology, University of Washington, Seattle, Washington, USA; The first two authors contributed equally to this work.
authors.forename: Richard B
authors.initials: RB
authors.lastname: Presland
authors.affiliation: Department of Oral Health Sciences, University of Washington, Seattle, Washington, USA; Present Address: South African Association for Marine Biological Research, Marine Parade 4056, Durban, KwaZulu-Natal, South Africa (DJP); Department of Biological Structure, University of Washington, Seattle, Washington, USA (OTL).
authors.forename: Owen T
authors.initials: OT
authors.lastname: Lawrence
authors.affiliation: Department of Oral Health Sciences, University of Washington, Seattle, Washington, USA; Present Address: South African Association for Marine Biological Research, Marine Parade 4056, Durban, KwaZulu-Natal, South Africa (DJP); Department of Biological Structure, University of Washington, Seattle, Washington, USA (OTL).
authors.forename: David J
authors.initials: DJ
authors.lastname: Pearton
authors.affiliation: Department of Dermatology, Yale University, New Haven, Connecticut, USA.
authors.forename: Leonard M
authors.initials: LM
authors.lastname: Milstone
authors.affiliation: Department of Molecular Biophysics and Biochemistry, Yale University, New Haven, Connecticut, USA.
authors.forename: Thomas A
authors.initials: TA
authors.lastname: Steitz
mesh_terms: D048948:14-3-3 Proteins / Q000235:genetics / Q000378:metabolism*; D017306:Annexin A2 / Q000378:metabolism*; D014408:Biomarkers, Tumor / Q000235:genetics / Q000378:metabolism*; D002478:Cells, Cultured; D003460:Crystallization; D000078404:Epidermal Cells; D004817:Epidermis / Q000378:metabolism*; D005095:Exoribonucleases / Q000235:genetics / Q000378:metabolism*; D000091344:Filaggrin Proteins; D055551:HSP27 Heat-Shock Proteins / Q000378:metabolism*; D006801:Humans; D007381:Intermediate Filament Proteins / Q000378:metabolism*; D015603:Keratinocytes / Q000166:cytology / Q000378:metabolism; D011485:Protein Binding; D021381:Protein Transport / Q000502:physiology; D009418:S100 Proteins / Q000378:metabolism; D012680:Sensitivity and Specificity; D013050:Spectrometry, Fluorescence
chemical_list: D048948:14-3-3 Proteins; D017306:Annexin A2; D014408:Biomarkers, Tumor; C000717249:FLG protein, human; D000091344:Filaggrin Proteins; D055551:HSP27 Heat-Shock Proteins; D007381:Intermediate Filament Proteins; D009418:S100 Proteins; C110294:S100A1 protein; D005095:Exoribonucleases; C413442:SFN protein, human