IVL
Available structures PDB Ortholog search: PDBe RCSB List of PDB id codes 1EU0
Identifiers
Aliases	IVL, involucrin
External IDs	OMIM: 147360; MGI: 96626; HomoloGene: 136793; GeneCards: IVL; OMA:IVL - orthologs
Gene location (Human) Chr. Chromosome 1 (human)[1] Band 1q21.3 Start 152,908,546 bp[1] End 152,911,886 bp[1]
Gene location (Mouse) Chr. Chromosome 3 (mouse)[2] Band 3 F1|3 40.14 cM Start 92,478,209 bp[2] End 92,481,042 bp[2]
RNA expression pattern Bgee Human Mouse (ortholog) Top expressed in gingival epithelium oral cavity skin of abdomen skin of leg vulva skin of thigh mucosa of pharynx testicle amniotic fluid human penis Top expressed in transitional epithelium of urinary bladder skin of external ear skin of back umbilical cord lip skin of abdomen epidermis granular layer of epidermis hair follicle condyle More reference expression data BioGPS More reference expression data
Gene ontology Molecular function protein-macromolecule adaptor activity protein binding structural molecule activity Cellular component cytoplasm extracellular exosome cornified envelope centrosome cytosol nuclear body Biological process response to UV-B peptide cross-linking keratinization isopeptide cross-linking via N6-(L-isoglutamyl)-L-lysine keratinocyte differentiation cornification Sources:Amigo / QuickGO
Orthologs Species Human Mouse Entrez 3713 16447 Ensembl ENSG00000163207 ENSMUSG00000049128 UniProt P07476 P48997 RefSeq (mRNA) NM_005547 NM_008412 RefSeq (protein) NP_005538 NP_032438 Location (UCSC) Chr 1: 152.91 – 152.91 Mb Chr 3: 92.48 – 92.48 Mb PubMed search [3] [4]
Wikidata
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Involucrin is a protein component of human skin and in humans is encoded by the IVL gene.^[5][6] In binding the protein loricrin, involucrin contributes to the formation of a cell envelope that protects corneocytes in the skin.

This gene is mapped to 1q21, among calpactin I light chain, trichohyalin, profillaggrin, loricrin, and calcyclin.^[6]

Involucrin is a highly reactive, soluble, transglutaminase substrate protein present in keratinocytes of epidermis and other stratified squamous epithelia.^[7][8] It first appears in the cell cytosol, but ultimately becomes cross-linked to membrane proteins by transglutaminase thus helping in the formation of an insoluble envelope beneath the plasma membrane functioning as a glutamyl donor during assembly of the cornified envelope.^[9]

Involucrin is synthesised in the stratum spinosum and cross linked in the stratum granulosum by the transglutaminase enzyme that makes it highly stable. Thus it provides structural support to the cell, thereby allowing the cell to resist invasion by micro-organisms.^{[citation needed]}

Apigenin, a plant-derived flavanoid that has significant promise as a skin cancer chemopreventive agent, has been found to regulate normal human keratinocyte differentiation by suppressing involucrin, and this is associated with reduced cell proliferation without apoptosis.^[10]

As one of the precursor proteins of the cornified cell envelope, involucrin is markedly increased in inflammatory skin diseases such as psoriasis^[11]

Lamellar ichthyosis involves a decrease in expression of involucrin. This decrease could contribute to the altered desquamation process seen in the disease, since the clinical improvement associated with retinoid treatment is accompanied by increased expression of involucrin.^[12]

Involucrin consists of a conserved N-terminal region of about 75 amino acid residues followed by two extremely variable length segments that contain glutamine-rich tandem repeats. The glutamine residues in the tandem repeats are the substrate for the transglutaminase in the cross-linking reaction. The total size of the protein varies from 285 residues (in dog) to 835 residues (in orangutan).^{[citation needed]}