Phenotypic Mutation 'Disruptive' (pdf version)
AlleleDisruptive
Mutation Type missense
Chromosome4
Coordinate11,784,654 bp (GRCm39)
Base Change A ⇒ G (forward strand)
Gene Cdh17
Gene Name cadherin 17
Synonym(s) BILL-cadherin, HPT-1, LI-cadherin
Chromosomal Location 11,758,157-11,817,905 bp (+) (GRCm39)
MGI Phenotype FUNCTION: [Summary is not available for the mouse gene. This summary is for the human ortholog.] This gene is a member of the cadherin superfamily, genes encoding calcium-dependent, membrane-associated glycoproteins. The encoded protein is cadherin-like, consisting of an extracellular region, containing 7 cadherin domains, and a transmembrane region but lacking the conserved cytoplasmic domain. The protein is a component of the gastrointestinal tract and pancreatic ducts, acting as an intestinal proton-dependent peptide transporter in the first step in oral absorption of many medically important peptide-based drugs. The protein may also play a role in the morphological organization of liver and intestine. Alternative splicing results in multiple transcript variants. [provided by RefSeq, Jan 2009]
PHENOTYPE: Homozygous mutant mice exhibit impaired B lymphocyte development and impaired IgG1 and IgG3 antibody response to T-independent antigen. [provided by MGI curators]
Accession Number

NCBI RefSeq: NM_019753; MGI:1095414

MappedYes 
Amino Acid Change Tyrosine changed to Cysteine
Institutional SourceBeutler Lab
Gene Model predicted gene model for protein(s): [ENSMUSP00000029871] [ENSMUSP00000103938]
AlphaFold Q9R100
SMART Domains Protein: ENSMUSP00000029871
Gene: ENSMUSG00000028217
AA Change: Y270C

DomainStartEndE-ValueType
signal peptide 1 21 N/A INTRINSIC
CA 44 123 5.27e-10 SMART
CA 147 241 6.9e-14 SMART
CA 258 337 3.05e-15 SMART
CA 361 446 3.29e-11 SMART
CA 471 564 5.27e-10 SMART
CA 587 664 5.59e-23 SMART
Blast:CA 687 771 5e-39 BLAST
transmembrane domain 784 806 N/A INTRINSIC
Predicted Effect probably damaging

PolyPhen 2 Score 1.000 (Sensitivity: 0.00; Specificity: 1.00)
(Using ENSMUST00000029871)
SMART Domains Protein: ENSMUSP00000103938
Gene: ENSMUSG00000028217
AA Change: Y270C

DomainStartEndE-ValueType
signal peptide 1 21 N/A INTRINSIC
CA 44 123 5.27e-10 SMART
CA 147 241 6.9e-14 SMART
CA 258 337 3.05e-15 SMART
CA 361 446 3.29e-11 SMART
CA 471 564 5.27e-10 SMART
CA 587 664 5.59e-23 SMART
Predicted Effect probably damaging

PolyPhen 2 Score 1.000 (Sensitivity: 0.00; Specificity: 1.00)
(Using ENSMUST00000108303)
Meta Mutation Damage Score 0.9470 question?
Is this an essential gene? Probably nonessential (E-score: 0.186) question?
Phenotypic Category Autosomal Semidominant
Candidate Explorer Status loading ...
Single pedigree
Linkage Analysis Data
Penetrance  
Alleles Listed at MGI

All Mutations and Alleles(7) : Gene trapped(2) Spontaneous(1) Targeted(3) Transgenic(1)

Lab Alleles
AlleleSourceChrCoordTypePredicted EffectPPH Score
IGL00715:Cdh17 APN 4 11797780 splice site probably benign
IGL00823:Cdh17 APN 4 11783412 missense possibly damaging 0.78
IGL00824:Cdh17 APN 4 11784675 missense probably benign 0.00
IGL01572:Cdh17 APN 4 11784621 splice site probably benign
IGL01602:Cdh17 APN 4 11795670 missense probably damaging 1.00
IGL01605:Cdh17 APN 4 11795670 missense probably damaging 1.00
IGL01759:Cdh17 APN 4 11771262 splice site probably benign
IGL02065:Cdh17 APN 4 11771373 splice site probably benign
IGL02448:Cdh17 APN 4 11784680 missense probably benign
IGL02869:Cdh17 APN 4 11814908 missense probably benign 0.00
IGL03088:Cdh17 APN 4 11810473 missense probably damaging 1.00
G1Funyon:Cdh17 UTSW 4 11795659 missense probably damaging 0.99
R0054:Cdh17 UTSW 4 11785186 missense possibly damaging 0.59
R0081:Cdh17 UTSW 4 11785280 splice site probably benign
R0101:Cdh17 UTSW 4 11771341 missense probably benign 0.00
R0432:Cdh17 UTSW 4 11771273 nonsense probably null
R0718:Cdh17 UTSW 4 11810451 missense possibly damaging 0.68
R0946:Cdh17 UTSW 4 11795581 missense probably benign 0.01
R1076:Cdh17 UTSW 4 11795581 missense probably benign 0.01
R1217:Cdh17 UTSW 4 11799676 missense probably benign 0.04
R2060:Cdh17 UTSW 4 11803982 missense probably benign 0.03
R3808:Cdh17 UTSW 4 11795671 missense probably damaging 0.99
R3850:Cdh17 UTSW 4 11785201 missense probably damaging 1.00
R4111:Cdh17 UTSW 4 11814628 missense probably damaging 0.99
R4112:Cdh17 UTSW 4 11814628 missense probably damaging 0.99
R4583:Cdh17 UTSW 4 11810466 missense probably benign 0.00
R4683:Cdh17 UTSW 4 11817036 missense possibly damaging 0.78
R4797:Cdh17 UTSW 4 11810390 missense probably benign 0.00
R5050:Cdh17 UTSW 4 11784654 missense probably damaging 1.00
R5071:Cdh17 UTSW 4 11810325 missense probably damaging 0.98
R5569:Cdh17 UTSW 4 11816990 missense probably damaging 0.96
R5790:Cdh17 UTSW 4 11814945 splice site probably null
R6077:Cdh17 UTSW 4 11803969 missense probably benign 0.22
R6581:Cdh17 UTSW 4 11799615 missense probably damaging 1.00
R7274:Cdh17 UTSW 4 11783174 nonsense probably null
R7647:Cdh17 UTSW 4 11814698 missense probably damaging 1.00
R7649:Cdh17 UTSW 4 11814698 missense probably damaging 1.00
R7934:Cdh17 UTSW 4 11799754 critical splice donor site probably null
R8290:Cdh17 UTSW 4 11817037 missense probably benign
R8301:Cdh17 UTSW 4 11795659 missense probably damaging 0.99
R8690:Cdh17 UTSW 4 11783163 missense probably benign 0.05
R8709:Cdh17 UTSW 4 11795685 nonsense probably null
R8818:Cdh17 UTSW 4 11771323 missense probably damaging 1.00
R8940:Cdh17 UTSW 4 11783226 missense probably damaging 1.00
R9243:Cdh17 UTSW 4 11771333 missense probably benign 0.26
R9325:Cdh17 UTSW 4 11810319 missense probably damaging 0.99
R9457:Cdh17 UTSW 4 11771329 missense probably damaging 0.98
X0067:Cdh17 UTSW 4 11785224 missense probably damaging 0.99
Mode of Inheritance Autosomal Semidominant
Local Stock
Repository
Last Updated 2019-09-04 9:39 PM by Anne Murray
Record Created 2017-07-03 12:48 PM by Bruce Beutler
Record Posted 2019-03-20
Phenotypic Description

Figure 1. Disruptive mice exhibit decreased IgD expression on peripheral B cells. Flow cytometric analysis of peripheral blood was utilized to determine IgD MFI. Normalized gene-based superpedigree data are shown. Abbreviations: WT, wild-type; REF, homozygous reference mice; HET, heterozygous variant mice; VAR, homozygous variant mice. Mean (μ) and standard deviation (σ) are indicated.

Figure 2. Disruptive mice exhibit susceptibility to dextran sulfate sodium (DSS)-induced colitis 7 days after DSS treatment. Normalized data are shown. Abbreviations: WT, wild-type; REF, homozygous reference mice; HET, heterozygous variant mice; VAR, homozygous variant mice. Mean (μ) and standard deviation (σ) are indicated.

Figure 3. Disruptive mice exhibit susceptibility to dextran sulfate sodium (DSS)-induced colitis 10 days after DSS treatment. Normalized data are shown. Abbreviations: WT, wild-type; REF, homozygous reference mice; HET, heterozygous variant mice; VAR, homozygous variant mice. Mean (μ) and standard deviation (σ) are indicated.

The Disruptive phenotype was identified among N-ethyl-N-nitrosourea (ENU)-mutagenized G3 mice of the pedigree R5050, some of which showed reduced IgD expression on peripheral blood B cells (gene-based superpedigree analysis; Figure 1) and susceptibility to dextran sulfate sodium (DSS)-induced colitis 7 (Figure 2) and 10 (Figure 3) days after DSS treatment.

Nature of Mutation

Figure 3. Linkage mapping of DSS susceptibility phenotype using an additive model of inheritance. Manhattan plot shows -log10 P values (Y-axis) plotted against the chromosome positions of 61 mutations (X-axis) identified in the G1 male of pedigree R5050. Normalized phenotype data are shown for single locus linkage analysis without consideration of G2 dam identity. Horizontal pink and red lines represent thresholds of P = 0.05, and the threshold for P = 0.05 after applying Bonferroni correction, respectively.

Whole exome HiSeq sequencing of the G1 grandsire identified 61 mutations. Both of the above anomalies were linked by continuous variable mapping to a mutation in Cdh17:  an A to G transition at base pair 11,784,654 (v38) on chromosome 4, or base pair 26,498 in the GenBank genomic region NC_000070 encoding Cdh17. The strongest association was found with an additive model of linkage to the normalized DSS phenotype, wherein nine variant homozygotes and 37 heterozygous mice departed phenotypically from 23 homozygous reference mice with a P value of 3.854 x 10-6 (Figure 4).  A recessive model of inheritance was observed for the IgD phenotype (gene-based superpedigree analysis; P = 5.022 x 10-5). 

The mutation corresponds to residue 956 in the mRNA sequence NM_019753 within exon 8 of 18 total exons.

 
940 GACCCAGGGGCCCAGTATTCCTTAGTCAACAAG

265 -D--P--G--A--Q--Y--S--L--V--N--K-

 

The mutated nucleotide is indicated in red.  The mutation results in a tyrosine to cysteine substitution at position 270 (Y270C) in the CDH17 protein, and is strongly predicted by PolyPhen-2 to be damaging (score = 1.000).

Illustration of Mutations in
Gene & Protein
Protein Prediction
Figure 4. Domain organization of CDH17. The Disruptive mutation results in a tyrosine to cysteine substitution at position 270. Abbreviations: SP, signal peptide; EC, extracellular; TM, transmembrane domain.

Cdh17 encodes cadherin 17 (CDH17; alternatively, LI-cadherin [liver-intestine cadherin] or BILL-cadherin [B lineage-, intestine-, liver-, and leukocyte-cadherin] in the mouse). CDH17 is a member of the seven domain (7D) subfamily of cadherins. The cadherin proteins share similar features including a signal peptide, an extracellular domain with a variable number (CDH17 has seven) of extracellular ectodomain (EC) repeats (alternatively, cadherin motifs), a single helical transmembrane domain, and a cytoplasmic C-terminus (Figure 4(1). The EC repeats are each approximately 110 amino acids arranged in a b-barrel structure similar to the Greek-key topology of immunoglobulin domains, with seven β-strands arranged as two opposing β-sheets with N- and C-termini at the opposite ends (1;2). Similar to other members of the cadherin family, each CDH17 EC repeat has four calcium binding motifs that together bind three calcium ions. Calcium binding facilitates linearization and rigidification of the cadherin ectodomain, prevents ectodomain unfolding, and promotes cadherin dimerization and consequent cell-cell adhesion (2). CDH17 has a RGD motif (amino acids 603 to 605 in human CDH17) within the sixth EC repeat that binds and induces α2β1 integrin activation as well as promotes focal adhesion kinase and ERK1 (see the record for wabasha)/ERK2 activation in KM12SM colon cancer cells (3;4). CDH17-associated α2β1 integrin activation and subsequent focal adhesion kinase and Ras activation regulates cell proliferation, adhesion, and liver metastasis of the KM12SM cells (4).

The intracellular portion of most cadherins is highly conserved (5), and mediates interactions with cytoplasmic catenins (e.g., α- and β-catenin), which link the cadherins to the actin cytoskeleton (6;7)). However, the intracellular C-terminal tail of CDH17 does not bind b-catenin or other known cytoplasmic components to mediate its adhesive functions; the function of the C-terminal tail of CDH17 is unknown (8).

The Disruptive mutation results in a tyrosine to cysteine substitution at position 270 (Y270C); residue 270 is within the second of seven EC repeats.

Expression/Localization

CDH17 is expressed in the colon, intestine, and pancreas in humans (9). CDH17 is highly expressed in intestinal metaplasia and adenocarcinomas of the stomach (10). In rats, CDH17 is highly expressed in the liver and small intestine in rats (11), and in the small intestine and colon of the mouse. Mouse CDH17 is expressed in the intestine as early as embryonic day 12.5 (E12.5), and is observed until E16.5 (12). CDH17 is expressed in the liver at E13.5 and E16.5, but was not detected in postnatal mice. CDH17 is expressed on mouse B cells in a spatiotemporally-regulated manner: it is expressed during the pro-B/pre-B-I stages, is downregulated during the pre-B-II stage, and is upregulated on immature B cells (13). Half of all memory B cells express CDH17 during the later stage of development (14).

CDH17 localized to the basolateral surface of hepatocytes in rat liver (11) and is localized to the lateral contact areas in intestinal epithelial cells (11;12). CDH17 is expressed in the enterocytes along the entire crypt-villus axis of the intestinal epithelium (11).

Background
Figure 5. Putative CDH17 function. A tight junction in the intestinal mucosa is represented. In the intestinal epithelium, CDH17 putatively promotes the binding of α2β1 integrin to collagen type IV within the extracellular matrix to maintain tissue integrity in the epithelia.

Cadherins are glycoproteins that mediate calcium-dependent cell-cell adhesion (15). Cadherins are essential during tissue development and for the maintenance of junctional complexes between epithelial cells (16). The exact biological function of CDH17 is unknown; however, CDH17 functions as an intestinal proton-dependent peptide transporter in the first step in oral absorption of many medically important peptide-based drugs (9). CDH17 also functions as a cell adhesion protein to maintain tissue integrity in epithelia (Figure 5). CDH17 may also play a role in the morphological organization of liver and intestine (17).

CDH17 functions in the invasion and metastasis of colorectal cancer. RNAi-mediated reduction in CDH17 expression promoted cancer cell invasion, adhesion, and migration by degrading extracellular matrix components through activation of MMP-2 and -9 (18). CDH17 knockdown also increased cancer cell adhesion and migration through increased expression of galectin-3; galectin-3 is a substrate of MMP-2 and -9 (18). CDH17 mediates increased expression of MMP-2 and -9, resulting in reduced galectin-3 expression. Aberrant cadherin-mediated cell adhesion putatively promotes the transition from the epithelial to mesenchymal stage during tumor proliferation and cell invasion (19;20). CDH17 overexpression results in epithelial-mesenchymal transition, putatively through destabilization of the E-cadherin/catenin complex, inhibition of GSK-3β/Axin-based proteosome activity, and activation of cyclooxygenase 2/cyclic adenosine monophosphate/protein kinase A signaling pathway (21). Accumulation of β-catenin would result in LEF/TCF-mediated transcription of Wnt-responsive genes, such as cyclin D1 leading to HCC cell proliferation and metastasis. CDH17 inhibition results in inactivation of Wnt-associated signaling and subsequent reduced tumor growth in hepatocellular carcinoma (21).

CDH17 is a putative differentiation marker for human gastric, pancreatic, intrahepatic cholangiocarcinoma, and hepatocellular carcinomas (22-28). Reduced CDH17 expression in colorectal and pancreatic cancers results in dedifferentiation, tumor invasion, and poor survival (22;29;30). Two CDH17 polymorphisms (651C>T and IVS6+35A>G) are a genetic susceptibility factor for the development of hepatocellular carcinoma in a Chinese population (31). Reduced CDH17 expression is associated with a high tumor grade, lymphatic invasion, lymph node metastasis in human colorectal carcinoma (29). In contrast, high expression of CDH17 in gastric cancer was associated with lymph node metastasis (32). High expression in liver cancer resulted in poor survival, tumor recurrence, tumor invasion, and metastasis (21;33).

CDH17 putatively functions in long-term survival and proliferation of memory B cells (14). Cdh17-deficient (Cdh17-/-) mice exhibited increased numbers of pro-B and pre-B cells in the bone marrow with concomitant reduced numbers of mature B cells in the bone marrow and spleen as well as reduced numbers of B1a cells in the peritoneal cavity (13). The IgG1 and IgG3 responses to the T-independent antigen NP-Ficoll were diminished, but the responses to the T-dependent antigen DNP-KLH were normal (13). Non-immunized Cdh17-/- mice had reduced sizes and numbers of germinal centers (13). Cdh17-/- mice showed impaired maintenance of high-affinity antigen-specific serum antibodies as well as reduced numbers of antigen-specific memory B cells compared to wild-type mice (14). The mice also showed aberrant specific responses to secondary antigens; primary antibody responses were comparable to that in wild-type mice (14). Memory B cells from the Cdh17-/- mice showed reduced proliferation compared to wild-type memory B cells.

Putative Mechanism

CDH17 putatively functions in regulating the width of the intercellular cleft and influencing water transport in the kidney and intestine (34;35). Cdh17-/- mice showed increased intestinal epithelium permeability and susceptibility to DSS-induced colitis (36). The intestinal mucosa has epithelium that mediates the selective uptake of nutrients and ions, the resorption of water, and the prevention of pathogen invasion. The epithelium undergoes continuous and rapid self-renewal while maintaining tight cell-cell adhesion (37). E-cadherin and CDH17 are the predominant cadherins expressed in the intestinal mucosal epithelium (11). E-cadherin is important for the integrity of the intestinal epithelial barrier and for the migration rate of enterocytes (38;39). CDH17 assists in maintaining the lateral adhesiveness of the epithelium possibly through an interaction with a yet unidentified cytoplasmic protein or with other membrane proteins.

The phenotype of the Disruptive mice indicates loss of CDH17-associated function in maintaining the intestinal epithelium integrity.

Primers PCR Primer
Disruptive_pcr_F: GGAAGAAAGAATTCCCTTGTCTGC
Disruptive_pcr_R: TGCACAAACATCCAGGATCTAG

Sequencing Primer
Disruptive_seq_F: AGAATTCCCTTGTCTGCTTTTAAGG
Disruptive_seq_R: CCAGGATCTAGAACACAGTTTTG
Genotyping

PCR program

1) 94°C 2:00
2) 94°C 0:30
3) 55°C 0:30
4) 72°C 1:00
5) repeat steps (2-4) 40x
6) 72°C 10:00
7) 4°C hold


The following sequence of 462 nucleotides is amplified (chromosome 4, + strand):


1   ggaagaaaga attcccttgt ctgcttttaa ggttagttta ggttgagaat tttaaatatg
61  ttactcagtt gccttaagaa actgctcatg tgcagacaga gttgtgagaa attccaaagt
121 gagaatatag aagctgttga tcaccttttc agtctgttaa ttcttgtgtt ttttcccacc
181 actcgctttg gccgtgcagg tgcagtggaa tgacccaggg gcccagtatt ccttagtcaa
241 caaggagaag ctgtcgccgt tcccattctc gatcgaccaa gaaggaaata tttatgtgac
301 tcaggccttg gaccgggagg aaaagaactc agtgagtgag acgggatgtt ccgtgggcca
361 caagacaaat cctatgtcta cttacaattg aggacaaatt aattgtaaat tattaaaaaa
421 aaatggaaca aaactgtgtt ctagatcctg gatgtttgtg ca


Primer binding sites are underlined and the sequencing primers are highlighted; the mutated nucleotide is shown in red.

References
Science Writers Anne Murray
AuthorsEmre Turer, Xue Zhong, Jin Huk Choi, and Bruce Beutler