An intronic enhancer driven by NF-κB contributes to transcriptional regulation of peptidylarginine deiminase type I gene in human keratinocytes.
Peptidylarginine deiminases (PADs) catalyze the conversion of protein-bound arginine to citrulline residues. In human epidermis, where filaggrin is the main deiminated protein, three PADs are detected with specific patterns of expression depending on the keratinocyte (KC) differentiation state. Previous characterizations of the PAD-encoding gene promoters have shown that proximal regulation alone is not sufficient to explain this specificity of expression. In this work, we describe an evolutionarily highly conserved nucleotide segment located in the first intron of the PAD1 gene (PADI1). Luciferase reporter assays showed that it enhances the activity of the PADI1 promoter, in a calcium- and orientation-independent manner. Mutation of a putative NF-κB cis-element markedly reduced its enhancer activity, which also confirmed its potential regulatory function. Chromatin immunoprecipitation assays evidenced the binding of both p65 and p50 NF-κB subunits to the cis-element, and RNA interference inhibition assays confirmed that NF-κB contributes to the PADI1 transcriptional control. Furthermore, the intronic enhancer and promoter of PADI1 potentially interact through chromatin looping, as indicated by chromosome conformation capture assays. Our findings provide evidence that an NF-κB-mediated signaling pathway is involved in PADI1 regulation in human epidermal KCs.
Ying
Shibo
S
Department of Applied Life Sciences, United Graduate School of Agricultural Science, Tokyo University of Agriculture and Technology, Tokyo, Japan.
Kojima
Toshio
T
Kawada
Akira
A
Nachat
Rachida
R
Serre
Guy
G
Simon
Michel
M
Takahara
Hidenari
H
D001483:Base Sequence; D002460:Cell Line; D002843:Chromatin / Q000235:genetics; D017124:Conserved Sequence; D004742:Enhancer Elements, Genetic / Q000502:physiology*; D000091344:Filaggrin Proteins; D015971:Gene Expression Regulation, Enzymologic / Q000502:physiology*; D006801:Humans; D006867:Hydrolases / Q000235:genetics*; D007438:Introns / Q000235:genetics; D015603:Keratinocytes / Q000166:cytology / Q000502:physiology*; D008969:Molecular Sequence Data; D052002:NF-kappa B p50 Subunit / Q000378:metabolism*; D011401:Promoter Regions, Genetic / Q000502:physiology; D000080062:Protein-Arginine Deiminase Type 1; D015398:Signal Transduction / Q000502:physiology; D051996:Transcription Factor RelA / Q000378:metabolism*; D014158:Transcription, Genetic / Q000502:physiology
D002843:Chromatin; C000717249:FLG protein, human; D000091344:Filaggrin Proteins; D052002:NF-kappa B p50 Subunit; D051996:Transcription Factor RelA; D006867:Hydrolases; D000080062:Protein-Arginine Deiminase Type 1