LEKTI-2

Lympho-epithelial Kazal-type related inhibitor 2 (LEKTI-2) is a protein encoded by the SPINK9 gene in humans. SPINK9 is a member of a gene family cluster located on chromosome 5q33.1, which includes SPINK5 and SPINK6.^[3] LEKTI-2 is an inhibitor of KLK5.

SPINK9
Identifiers
Aliases	SPINK9, LEKTI2, serine peptidase inhibitor, Kazal type 9, serine peptidase inhibitor Kazal type 9
External IDs	OMIM: 613511; HomoloGene: 88638; GeneCards: SPINK9; OMA:SPINK9 - orthologs
Gene location (Human) Chr. Chromosome 5 (human)[1] Band 5q32 Start 148,321,203 bp[1] End 148,339,852 bp[1]
RNA expression pattern Bgee Human Mouse (ortholog) Top expressed in testicle corpus callosum gonad Achilles tendon nucleus accumbens anterior cingulate cortex Brodmann area 9 right auricle of heart granulocyte fundus n/a More reference expression data BioGPS n/a
Gene ontology Molecular function peptidase inhibitor activity protein binding serine-type endopeptidase inhibitor activity Cellular component extracellular region acrosomal vesicle extracellular space Biological process negative regulation of peptidase activity negative regulation of serine-type endopeptidase activity cornification regulation of acrosome reaction negative regulation of endopeptidase activity Sources:Amigo / QuickGO
Orthologs Species Human Mouse Entrez 643394 n/a Ensembl ENSG00000204909 n/a UniProt Q5DT21 n/a RefSeq (mRNA) NM_001040433 n/a RefSeq (protein) NP_001035523 n/a Location (UCSC) Chr 5: 148.32 – 148.34 Mb n/a PubMed search [2] n/a
Wikidata
View/Edit Human

Desquamation

The outer layer of the epidermis is called the stratum corneum. In the stratum corneum terminally differentiated corneocytes are held together by corneodesmosomes. In order for desquamation to occur, corneodesmosomes need to be fully degraded. KLK5 and KLK7 are two serine proteases that degrade corneodesmosomes. LEKTI-2 regulates corneodesmosome degradation by inhibiting KLK5. In acral (palm and sole) skin, where desquamation needs to be delayed, SPINK9 expression is strongly upregulated.^[4] The resulting high level of LEKTI-2 delays corneodesmosome degradation, thereby allowing the epidermis to form a thick protective stratum corneum layer.^[4]

Clinical Significance

SPINK9 is overexpressed in lichen simplex chronicus, actinic keratosis, and squamous cell carcinoma.^[5]

See also

• Kazal-type serine protease inhibitor domain