Phenotypic Mutation 'Spikey' (pdf version)
AlleleSpikey
Mutation Type missense
Chromosome11
Coordinate99,902,765 bp (GRCm39)
Base Change A ⇒ T (forward strand)
Gene Krt33a
Gene Name keratin 33A
Synonym(s) 2310015J09Rik
Chromosomal Location 99,902,025-99,907,038 bp (-) (GRCm39)
MGI Phenotype PHENOTYPE: Mutations of this gene cause the hair coat to appear either shiny, reflective and "polished" or greasy looking, disheveled and "spikey." [provided by MGI curators]
Accession Number

NCBI RefSeq: NM_027983, MGI: 1919138

MappedYes 
Amino Acid Change Isoleucine changed to Asparagine
Institutional SourceBeutler Lab
Gene Model not available
AlphaFold Q8K0Y2
SMART Domains Protein: ENSMUSP00000018399
Gene: ENSMUSG00000035592
AA Change: I353N

DomainStartEndE-ValueType
low complexity region 11 26 N/A INTRINSIC
Filament 55 366 1.99e-148 SMART
internal_repeat_1 368 385 6.11e-5 PROSPERO
internal_repeat_1 384 399 6.11e-5 PROSPERO
Predicted Effect probably damaging

PolyPhen 2 Score 1.000 (Sensitivity: 0.00; Specificity: 1.00)
(Using ENSMUST00000018399)
Meta Mutation Damage Score Not available question?
Is this an essential gene? Probably nonessential (E-score: 0.076) question?
Phenotypic Category Autosomal Dominant
Candidate Explorer Status loading ...
Single pedigree
Linkage Analysis Data
Penetrance 100% 
Alleles Listed at MGI
All alleles(5) : Targeted, other(2) Chemically induced(3)
Lab Alleles
AlleleSourceChrCoordTypePredicted EffectPPH Score
IGL01803:Krt33a APN 11 99902843 missense probably benign 0.35
IGL02412:Krt33a APN 11 99902805 missense probably benign 0.01
IGL02523:Krt33a APN 11 99902518 missense probably benign 0.02
Polished UTSW 11 99903437 missense probably damaging 1.00
Polished2 UTSW 11 99906676 missense probably benign 0.10
R0492:Krt33a UTSW 11 99906909 missense probably benign 0.02
R0496:Krt33a UTSW 11 99903155 splice site probably benign
R0691:Krt33a UTSW 11 99903541 missense probably damaging 1.00
R1077:Krt33a UTSW 11 99906763 missense probably benign
R1624:Krt33a UTSW 11 99905072 missense probably damaging 1.00
R1911:Krt33a UTSW 11 99903175 missense probably benign 0.35
R1944:Krt33a UTSW 11 99903535 missense probably benign 0.10
R1945:Krt33a UTSW 11 99903535 missense probably benign 0.10
R2254:Krt33a UTSW 11 99905004 missense possibly damaging 0.95
R2255:Krt33a UTSW 11 99905004 missense possibly damaging 0.95
R3716:Krt33a UTSW 11 99904991 missense probably benign 0.01
R4377:Krt33a UTSW 11 99903253 missense possibly damaging 0.46
R5233:Krt33a UTSW 11 99904961 missense probably damaging 1.00
R6029:Krt33a UTSW 11 99903289 missense probably benign 0.01
R6316:Krt33a UTSW 11 99905027 missense probably damaging 0.98
R6807:Krt33a UTSW 11 99903209 missense possibly damaging 0.61
R7272:Krt33a UTSW 11 99902837 missense probably damaging 1.00
R7323:Krt33a UTSW 11 99902801 missense probably benign 0.08
R7461:Krt33a UTSW 11 99902765 missense probably damaging 1.00
R7613:Krt33a UTSW 11 99902765 missense probably damaging 1.00
R7657:Krt33a UTSW 11 99906693 missense probably benign
R7748:Krt33a UTSW 11 99902428 missense probably benign
R8183:Krt33a UTSW 11 99905575 critical splice donor site probably null
R8554:Krt33a UTSW 11 99903209 missense possibly damaging 0.61
R8841:Krt33a UTSW 11 99904961 missense probably damaging 1.00
R9587:Krt33a UTSW 11 99906733 missense probably damaging 1.00
R9655:Krt33a UTSW 11 99906624 critical splice donor site probably null
Z1176:Krt33a UTSW 11 99902740 missense probably benign 0.14
Mode of Inheritance Autosomal Dominant
Local Stock Embryos
MMRRC Submission 030961-UCD
Last Updated 2016-05-13 3:09 PM by Stephen Lyon
Record Created unknown
Record Posted 2009-02-25
Phenotypic Description

The dominant Spikey mutation was identified in N-ethyl-N-nitrosourea (ENU)-induced G1 mutant mice.  Heterozygous Spikey mice have a somewhat greasy, unkempt appearance, with fur that is tufted and non-uniform (Figure 1).  Spikey mice show normal phenotypes when tested with Listeria monocytogenes  and mouse cytomegalovirus (MCMV) infection (MCMV Susceptibility and Resistance Screen), and normal macrophage responses to Toll-like receptor ligands (TLR Signaling Screen).

Nature of Mutation
The Spikey mutation was mapped to Chromosome 11, and corresponds to a T to A transversion at position 1123 of the Krt33a transcript, in exon 6 of 7 total exons. 
 
1107 CGTCTGGAGTGTGAGATCAACACGTACAGGGGC
348  -R--L--E--C--E--I--N--T--Y--R--G-
 
The mutated nucleotide is indicated in red lettering, and causes an isoleucine to asparagine change at residue 353 of the Keratin 33a (K33a) protein.
Illustration of Mutations in
Gene & Protein
Protein Prediction
Figure 2. Keratin domain structure showing the α-helical domain, linker regions and head/tail domains. The Spikey mutation results in the substitution of an asparagine for an isoleucine at amino acid 353 of the Keratin 33a protein. This image is interactive. Click on the image to view other mutations found in Krt33a (red). Click on the mutations for more specific information.   
The Spikey mutation results in the substitution of an asparagine for an isoleucine at amino acid 353 of Keratin 33a.  This conserved residue is located in the 2B α-helical rod subdomain, and is part of the HTM motif that forms interactions with other keratin molecules and is important in assembling intermediate filaments (Figure 2).  Mutations affecting this region in other keratin molecules commonly cause disease (please see the intermediate filament database at  www.interfil.org).   
 
Please see the record for Polished for information about Krt33a.
Primers Primers cannot be located by automatic search.
Genotyping
Spikey genotyping is performed by amplifying the region containing the mutation using PCR, followed by sequencing of the amplified region to detect the single nucleotide change.  
 
Primers for PCR amplification
Spikey(F): 5’- TTGCCTATTGCAGACAGAGGAGTTG -3’
Spikey(R): 5’- ACTGATGTTGTTTCACATGCTTGCC -3’
 
PCR program (use SIGMA JumpStart REDTaq)
1) 94°C             2:00
2) 94°C             0:30
3) 56°C             0:30
4) 72°C             1:00
5) repeat steps (2-4) 29X
6) 72°C             7:00
7) 4°C               ∞
 
Primers for sequencing
Spikey_seq(F): 5’- TCAATGCCCTGGAGATCGAG -3’
Spikey_seq(R): 5’- GAGTATTGTAGGCTCCCCAAGAC -3’
 
The following sequence of 1193 nucleotides (from Genbank genomic region NC_000077 for linear DNA sequence of Krt33a) is amplified:
 
3736                 ttgcc tattgcagac agaggagttg aacaagcagg tggtgtccag
3781 ctcagagcag ctgcagtcct gccaggccga gatcatcgag ctgagacgca cagtcaatgc
3841 cctggagatc gagctgcagg cccagcatga actggtgtgt agtgtctaga ctgctgctga
3901 gcagtgtgga gttgggaggc agagtcactg gggtgtcctt ggggcttctc tgtctctgtc
3961 tctgtctctg tctctgtctc tgtctctgtc tgtctctctt cttagctctt gaagcctgtg
4021 acttctctgg aagtcatgca gaaaccttca gagggaacag ctctgtgaca gcctttgtct
4081 tctcccccac agagaaactc tctggagaac accctgacag agagtgaggc tcgctacagc
4141 tcccagctgt cccaggtgca gtgcctgatc accaatgtgg agtcccagct tggtgagatc
4201 cgggctgacc tggagcgtca gaaccaggag taccaagtgc tgctggacat tcggtctcgt
4261 ctggagtgtg agatcaacac gtacaggggc ctgctggaga gcgaggactg caagtgagta
4321 tggctgcatg acttttcctt ggggtgagct gttttcttgg cgggagttaa tttacccctt
4381 tgcacttcta cctggtgaca tccaaaggaa aggccctagc ctgactgtgt ttctagtgtc
4441 ttcctgtgtg ttgaactcac tctaccctaa ctttctccaa tcatttcctg tctccaggct
4501 cccttgcaat ccctgtgcca caaccaatgc ttgtgataag cccattgggc cctgtgtccc
4561 taacccttgt gtcacacgac ctcgatgtgg accttgcaac acttttgtgc gttagagacg
4621 ccattgccag aaggggacaa ggataccagt tacatcgtaa tgccacccct tcccaagtcc
4681 tcaaagagtc accgcactgg acaaagacgg accagttctt ggcttcagtt caagcctaga
4741 gtgtattttc tcatttgatc cttgggcaca ggagatgcaa agtctgtctt ggggagccta
4801 caatactcac acaaagccat atttacatat gcaatgctgt gctttaataa aacttctcta
4861 aatgtgactg taaataactc cgttgagtgt ggaggatctg gttggcaagc atgtgaaaca
4921 acatcagt
 
PCR primer binding sites are underlined; sequencing primer binding sites are highlighted in gray; the mutated T is shown in red text.
Science Writers Nora G. Smart
Illustrators Diantha La Vine
AuthorsKarine Crozat, Xiao-Hong Li, Bruce Beutler.
Edit History
2011-01-07 9:32 AM (current)
2010-11-08 11:02 AM
2010-08-23 2:45 PM
2010-08-23 2:45 PM
2010-02-03 3:09 PM