Sharpin mutant mice possess loxP sites flanking exons 3-9 of the Sharpin (SHANK-associated RH domain interacting protein) gene on an albino C57BL/6 background and may be useful in generating conditional mutations to study atopic dermatitis, as well as, the role of SHARPIN in inflammation and NFKB regulation.
John P Sundberg, The Jackson Laboratory
Sharpin (SHANK-associated RH domain interacting protein) encodes a protein that is a component of the linear ubiquitin chain assembly complex (LUBAC). LUBAC is required for activation of the NFKB signaling pathway. Spontaneous mutations in Sharpin are associated with severe chronic autoinflammatory disease affecting multiple organs in particular, the skin (eg. cpdm – chronic proliferative dermatitis). These conditional albino mice possess loxP sites flanking exons 3-9 of the Sharpin gene. Mice that are homozygous for the albino (Tyrc-2J) and floxed Sharpin alleles are viable and fertile. When bred to mice that express tissue-specific Cre recombinase, resulting offspring will have the exons 3-9 deleted in cre-expressing tissues.
For example, when bred to mice with widespread Cre recombinase expression (B6.C-Tg(CMV-cre)1Cgn/J, Stock No. 006054), offspring develop prominent skin lesions, increased skin thickness, dermal inflammation and recapitulate the phenotype of the cpdm mutation.
When bred to mice with Cre recombinase expression in the epidermis and hair follicles (STOCK Tg(KRT14-cre)1Amc/J, Stock No. 004782), offspring develop chronic eosinophilic dermatitis, but do not develop inflammation in other organs.
When bred to mice with Cre recombinase expression in adipose tissue (B6;FVB-Tg(Adipoq-cre)1Evdr/J, Stock No. 010803), offspring do not appear to develop a phenotype.
The targeting construct contains a loxP site upstream of exon 3 and a loxP site downstream of exon 9 followed by an FRT-flanked neomycin cassette. The construct was electroporated into B6(Cg)-Tyrc-2J/J-derived embryonic stem (ES) cells. Correctly targeted ES cells were injected into blastocysts. The resulting chimeric animals were bred to B6.Cg-Tg(ACTFLPe)9205Dym/J (Stock No. 005703) mice to remove the neomycin cassette. Offspring were crossed to B6(Cg)-Tyrc-2J/J (Stock No. 000058) to remove the flp recombinase allele. Upon arrival, mice were bred to B6(Cg)-Tyrc-2J/J for at least 1 generation to establish the colony.
|Allele Name||albino 2 Jackson|
|Allele Type||Spontaneous (Null/Knockout)|
|Gene Symbol and Name||Tyr, tyrosinase|
|Site of Expression||Expressed in melanosomes|
|Strain of Origin||B6.Cg-Tyrp1b Hps1ep|
|Molecular Note||This mutation has a G-to-T base change at coding nucleotide 230 resulting in an amino acid change from arginine to leucine at residue 77 (p.R77L) which lies in the highly conserved DDRE sequence. Nucleotide 230 is at the alternative 5' splice donor site for exon 1 and this allele does not produce the 1a or 1b subset of tyrosinase transcripts but does produce a significant increase in 1c and 1d transcripts. Western blots of homozygous mutant skin extracts demostrate the nearly complete absence of the broad 76-84 kDa band of glycosylated wild-type tyrosinase. No tyrosinase activity was found in hairbulb extracts from homozygous mice.|
|Allele Name||targeted mutation 1.1, John Sundberg|
|Allele Type||Targeted (Conditional ready (e.g. floxed))|
|Gene Symbol and Name||Sharpin, SHANK-associated RH domain interacting protein|
|Strain of Origin||B6(Cg)-Tyrc-2J/J|
|Molecular Note||Exons 3-9 were flanked with loxP sites and an FRT-flanked neomycin selection cassette was also inserted and this selection cassette was excised by breeding to a germline flp deleter, yielding this conditional ready allele.|
Mice homozygous for both alleles are viable and fertile.
When using the B6.Cg-Tyrc-2J Sharpintm1.1Sun/J mouse strain in a publication, please cite the originating article(s) and include JAX stock #012631 in your Materials and Methods section.