Phenotypic Mutation 'Eeyore' (pdf version)
AlleleEeyore
Mutation Type missense
Chromosome7
Coordinate141,693,356 bp (GRCm38)
Base Change T ⇒ C (forward strand)
Gene Muc2
Gene Name mucin 2
Synonym(s) 2010015E03Rik
Chromosomal Location 141,276,583-141,308,428 bp (+) (GRCm39)
MGI Phenotype FUNCTION: [Summary is not available for the mouse gene. This summary is for the human ortholog.] This gene encodes a member of the mucin protein family. Mucins are high molecular weight glycoproteins produced by many epithelial tissues. The protein encoded by this gene is secreted and forms an insoluble mucous barrier that protects the gut lumen. The protein polymerizes into a gel of which 80% is composed of oligosaccharide side chains by weight. The protein features a central domain containing tandem repeats rich in threonine and proline that varies between 50 and 115 copies in different individuals. Downregulation of this gene has been observed in patients with Crohn disease and ulcerative colitis. [provided by RefSeq, Oct 2016]
PHENOTYPE: Homozygotes for a point mutation have soft feces at weaning and develop diarrhea associated with malapsorption syndrome. Homozygous null mutants pass blood in their feces at 6 months, and 65% of null mutants have intestinal tumors at 1 year. [provided by MGI curators]
Accession Number

NCBI RefSeq: NM_023566.2; MGI: 1339364

MappedYes 
Amino Acid Change Methionine changed to Isoleucine
Institutional SourceAustralian Phenomics Network
Gene Model not available
AlphaFold no structure available at present
SMART Domains Protein: ENSMUSP00000136692
Gene: ENSMUSG00000025515

DomainStartEndE-ValueType
C8 11 85 1.61e-32 SMART
Blast:VWD 102 128 5e-8 BLAST
Predicted Effect probably benign
SMART Domains Protein: ENSMUSP00000141040
Gene: ENSMUSG00000025515
AA Change: M194I

DomainStartEndE-ValueType
low complexity region 5 18 N/A INTRINSIC
VWD 20 183 1.5e-40 SMART
C8 216 290 3.9e-15 SMART
Pfam:TIL 293 349 5.4e-10 PFAM
VWC 351 411 7e-4 SMART
VWD 378 542 8.8e-44 SMART
C8 579 653 1.2e-36 SMART
SCOP:d1coua_ 654 728 4e-8 SMART
VWC_def 820 865 1.3e-2 SMART
Predicted Effect probably benign

PolyPhen 2 Score 0.353 (Sensitivity: 0.90; Specificity: 0.89)
(Using ENSMUST00000185406)
Meta Mutation Damage Score Not available question?
Is this an essential gene? Probably nonessential (E-score: 0.099) question?
Phenotypic Category Autosomal Semidominant
Candidate Explorer Status loading ...
Single pedigree
Linkage Analysis Data
Penetrance 100% 
Alleles Listed at MGI
All alleles(7) : Targeted, knock-out(1) Targeted, other(2) Chemically induced(4)  
Lab Alleles
AlleleSourceChrCoordTypePredicted EffectPPH Score
kenny APN 7 nonsense
Winnie APN 7 141286029 missense probably damaging 1.00
IGL01303:Muc2 APN 7 141306132 missense probably benign
IGL01482:Muc2 APN 7 141307797 missense probably damaging 0.96
IGL01875:Muc2 APN 7 141306477 missense probably damaging 0.99
IGL02088:Muc2 APN 7 141305241 missense probably damaging 1.00
IGL02415:Muc2 APN 7 141305609 nonsense probably null
IGL02548:Muc2 APN 7 141305594 missense probably damaging 1.00
IGL02836:Muc2 APN 7 141300450 unclassified probably benign
IGL03196:Muc2 APN 7 141301367 missense probably damaging 0.97
Muskatenwein UTSW 7 141307176 missense unknown
nomoco UTSW 7 141307456 missense probably damaging 1.00
Schlendrian UTSW 7 141281925 missense probably damaging 1.00
Seco UTSW 7 141284976 missense probably damaging 1.00
BB001:Muc2 UTSW 7 141281631 missense probably damaging 1.00
BB011:Muc2 UTSW 7 141281631 missense probably damaging 1.00
E0370:Muc2 UTSW 7 141282598 missense probably damaging 1.00
R0127:Muc2 UTSW 7 141302691 missense probably benign 0.00
R0179:Muc2 UTSW 7 141302708 missense probably damaging 1.00
R0201:Muc2 UTSW 7 141699185 frame shift probably null
R0299:Muc2 UTSW 7 141306466 missense probably damaging 1.00
R0547:Muc2 UTSW 7 141699185 frame shift probably null
R0699:Muc2 UTSW 7 141306037 missense probably damaging 1.00
R0900:Muc2 UTSW 7 141699185 frame shift probably null
R1348:Muc2 UTSW 7 141699185 frame shift probably null
R1466:Muc2 UTSW 7 141302711 missense probably damaging 1.00
R1466:Muc2 UTSW 7 141302711 missense probably damaging 1.00
R1625:Muc2 UTSW 7 141283405 missense probably damaging 1.00
R2010:Muc2 UTSW 7 141287444 missense probably damaging 0.99
R2149:Muc2 UTSW 7 141699185 frame shift probably null
R2163:Muc2 UTSW 7 141699185 frame shift probably null
R3008:Muc2 UTSW 7 141281347 missense possibly damaging 0.93
R3110:Muc2 UTSW 7 141299225 unclassified probably benign
R3112:Muc2 UTSW 7 141299225 unclassified probably benign
R3424:Muc2 UTSW 7 141279595 missense probably damaging 0.99
R3786:Muc2 UTSW 7 141283590 missense probably benign 0.01
R3854:Muc2 UTSW 7 141308081 missense probably damaging 1.00
R3964:Muc2 UTSW 7 141286233 missense probably benign 0.17
R3965:Muc2 UTSW 7 141286233 missense probably benign 0.17
R3966:Muc2 UTSW 7 141286233 missense probably benign 0.17
R3973:Muc2 UTSW 7 141300541 unclassified probably benign
R3974:Muc2 UTSW 7 141300541 unclassified probably benign
R3976:Muc2 UTSW 7 141300541 unclassified probably benign
R4327:Muc2 UTSW 7 141281577 missense probably damaging 0.96
R4694:Muc2 UTSW 7 141306082 missense probably damaging 1.00
R4764:Muc2 UTSW 7 141299345 missense possibly damaging 0.88
R4769:Muc2 UTSW 7 141286260 critical splice donor site probably null
R4798:Muc2 UTSW 7 141307877 missense probably benign 0.01
R4900:Muc2 UTSW 7 141303280 missense probably benign 0.32
R5383:Muc2 UTSW 7 141307456 missense probably damaging 1.00
R5489:Muc2 UTSW 7 141305169 missense probably benign 0.00
R5615:Muc2 UTSW 7 141277446 missense probably damaging 1.00
R5856:Muc2 UTSW 7 141299381 unclassified probably benign
R5919:Muc2 UTSW 7 141281171 missense probably damaging 0.97
R5953:Muc2 UTSW 7 141287951 missense probably damaging 0.96
R5979:Muc2 UTSW 7 141305143 missense probably damaging 0.99
R5979:Muc2 UTSW 7 141283493 splice site probably null
R6175:Muc2 UTSW 7 141282875 missense probably damaging 1.00
R6213:Muc2 UTSW 7 141305151 missense probably damaging 1.00
R6281:Muc2 UTSW 7 141306140 missense probably damaging 1.00
R6321:Muc2 UTSW 7 141287397 missense probably benign 0.28
R6390:Muc2 UTSW 7 141305883 missense probably damaging 0.97
R6485:Muc2 UTSW 7 141300473 unclassified probably benign
R6582:Muc2 UTSW 7 141282941 missense probably benign 0.00
R6683:Muc2 UTSW 7 141305214 missense probably benign 0.38
R6896:Muc2 UTSW 7 141306432 missense possibly damaging 0.48
R6906:Muc2 UTSW 7 141284976 missense probably damaging 1.00
R6924:Muc2 UTSW 7 141284077 missense possibly damaging 0.87
R7040:Muc2 UTSW 7 141305194 missense unknown
R7222:Muc2 UTSW 7 141290758 missense
R7251:Muc2 UTSW 7 141278965 missense possibly damaging 0.91
R7282:Muc2 UTSW 7 141306481 missense
R7315:Muc2 UTSW 7 141276645 missense probably damaging 0.99
R7421:Muc2 UTSW 7 141301863 missense
R7556:Muc2 UTSW 7 141307439 missense
R7651:Muc2 UTSW 7 141290750 missense
R7710:Muc2 UTSW 7 141287452 missense possibly damaging 0.92
R7776:Muc2 UTSW 7 141290942 missense
R7813:Muc2 UTSW 7 141282543 splice site probably null
R7843:Muc2 UTSW 7 141281662 missense probably benign 0.03
R7869:Muc2 UTSW 7 141303471 missense
R7924:Muc2 UTSW 7 141281631 missense probably damaging 1.00
R7993:Muc2 UTSW 7 141308173 missense
R8053:Muc2 UTSW 7 141284575 missense probably benign 0.01
R8068:Muc2 UTSW 7 141298422 missense
R8099:Muc2 UTSW 7 141299175 splice site probably null
R8192:Muc2 UTSW 7 141305215 missense
R8194:Muc2 UTSW 7 141290801 missense
R8545:Muc2 UTSW 7 141306130 missense unknown
R8701:Muc2 UTSW 7 141281850 missense probably damaging 1.00
R8883:Muc2 UTSW 7 141287469 missense probably damaging 0.98
R8894:Muc2 UTSW 7 141280758 missense probably damaging 1.00
R8905:Muc2 UTSW 7 141279643 missense probably benign 0.00
R9024:Muc2 UTSW 7 141287936 missense probably damaging 0.98
R9032:Muc2 UTSW 7 141287058 missense probably damaging 1.00
R9085:Muc2 UTSW 7 141287058 missense probably damaging 1.00
R9091:Muc2 UTSW 7 141290816 missense
R9104:Muc2 UTSW 7 141286224 missense probably damaging 1.00
R9114:Muc2 UTSW 7 141287983 nonsense probably null
R9270:Muc2 UTSW 7 141290816 missense
R9297:Muc2 UTSW 7 141302759 missense
R9325:Muc2 UTSW 7 141298559 missense
R9354:Muc2 UTSW 7 141307157 missense
R9386:Muc2 UTSW 7 141279389 missense probably damaging 1.00
R9529:Muc2 UTSW 7 141287453 missense possibly damaging 0.55
R9550:Muc2 UTSW 7 141308242 missense probably damaging 1.00
R9583:Muc2 UTSW 7 141300559 missense
R9607:Muc2 UTSW 7 141305190 missense
R9646:Muc2 UTSW 7 141276643 missense probably benign
R9651:Muc2 UTSW 7 141288014 missense probably damaging 0.99
R9774:Muc2 UTSW 7 141285811 missense probably benign
R9784:Muc2 UTSW 7 141280785 nonsense probably null
Z1176:Muc2 UTSW 7 141300451 missense
Z1177:Muc2 UTSW 7 141298531 missense
Mode of Inheritance Autosomal Semidominant
Local Stock Sperm, gDNA
Repository
Last Updated 2017-09-13 3:37 PM by Diantha La Vine
Record Created 2010-02-03 3:48 PM by Nora G. Smart
Record Posted 2010-02-04
Phenotypic Description
The Eeyore phenotype was identified amongst the G3 progeny of an ENU-treated C57BL/6 founder by their visible phenotype of spontaneous watery diarrhoea and high incidence of rectal bleeding and prolapse, suggestive of ulcerative colitis. Due to the similarities in phenotype between Winnie and Eeyore animals, these strains were crossed and noncomplementation was demonstrated indicating that both Winnie and Eeyore contained mutations within the same gene. Eeyore homozgyous animals exhibited a slightly more severe phenotype than Winnie homozygotes, with 40% dead by 1 year of age compared to 25% of Winnie animals having died. Compared with wild-type littermates, Eeyore small and large intestines were characterized by fewer goblet cells with smaller thecae, and a reduction in stored and secreted mucin. Eeyore homozygous mice also displayed increased intestinal epithelial proliferation and apoptosis (Figure 1).
 
In addition to spontaneous inflammation, Eeyore mice exhibited increased susceptibility to environmentally induced colitis. After being administered 2% of the luminal toxin dextran sodium sulfate (DSS), Eeyore showed earlier faecal occult blood than did wild-type mice (after exclusion of mice with spontaneous rectal bleeding or prolapses), and higher histological colitis scores after 3 days, whereas by day 7 colitis scores in wild-type mice were closer to those of mutant mice (Figure 2) (1).
Nature of Mutation
The Eeyore mutation corresponds to a T to C transition at position 5251 of the Muc2 transcript in exon 34 of 47 total exons (2).
 
5234 TCCTACAATGGCCTTTCTTTCTCCATCCGGCTG
1743  -S--Y--N--G--L--S--F--S--I--R--L-
 
The mutated nucleotide is indicated in red lettering, and causes a serine to proline change at amino acid 1748 of the MUC2 protein.
Illustration of Mutations in
Gene & Protein
Protein Prediction
Figure 3.  Domain structure of Mucin2. The Eeyore mutation causes a serine to proline change in the D4 domain of the MUC2 protein. S=Signal sequence; D=D domains (homology to VWF mediates trimerization); CR=Cystein-rich domain; TR= Tandem repeat domain (heavily O glycosylated); GDPH=GDPH autocatalytic proteolytic site; B=B domain (homology to VWF); C= C domain (homology to VWF); CK= Cysteine-knot domain (homology to VWF mediates dimerization). This image is interactive. Click on the image to view other mutations found in Mucin2 (red). Click on the mutations for more specific information.
The Eeyore mutation alters a serine residue located in the fourth VWF-like domain (Figure 3). 
 
For more information about Muc2, please see the record for Schlendrian.
Putative Mechanism
The Eeyore mutation alters a serine in the C-terminal VWF-like D4 domain of MUC2. The phenotype of Eeyore mutant mice suggests that this residue may affect MUC2 biosynthesis and assembly. While the D3 and CK domains of MUC2 have been implicated in trimerization and dimerization of MUC2 molecules through the formation of disulfide bonds (3-5), sequences present in the D4 domain may also play a role in intermolecular interactions between MUC2 molecules. The D4 domain contains a GDPH autocatalytic cleavage site with cleavage occurring between the D and P residues (6). It has been suggested that this cleavage leads to the formation of a unique covalent bond between the carboxy-terminal D residue of one MUC2 subunit and an oligosaccharide side chain present on another subunit. Although the serine residue affected by the Eeyore mutation is not located within this sequence, it is possible that the alteration of this residue may affect cleavage at the GDPH site. In Eeyore mice, the development of colitis resulted from the aberrant oligomerization and subsequent accumulation of MUC2 in the endoplasmic reticulum (ER), which leads to ER stress, triggering of the unfolded protein response (UPR), subsequent inflammation and goblet cell apoptosis (Figure 4) (1).
Primers Primers cannot be located by automatic search.
References
Science Writers Nora G. Smart
Illustrators Diantha La Vine
AuthorsChad K. Heazlewood, Matthew C. Cook, Rajaraman Eri, Gareth R. Price, Sharyn B. Tauro, Douglas Taupin, David J. Thornton, Chin Wen Png, Tanya L. Crockford, Richard J. Cornall, Rachel Adams, Masato Kato, Keats A. Nelms, Nancy A. Hong, Timothy H. J. Florin, Christopher C. Goodnow and Michael A. McGuckin
Edit History
2011-06-10 4:37 PM (current)
2011-04-24 11:21 AM
2011-01-04 2:51 PM
2010-12-16 11:45 AM
2010-10-14 1:41 PM
2010-10-14 1:26 PM
2010-10-14 8:31 AM
2010-10-14 8:30 AM
2010-10-06 9:43 AM
2010-08-10 11:06 AM
2010-08-10 11:04 AM
2010-04-08 4:57 PM
2010-03-03 9:31 AM