Phenotypic Mutation 'giza' (pdf version)
Allelegiza
Mutation Type missense
Chromosome11
Coordinate23,707,010 bp (GRCm39)
Base Change G ⇒ A (forward strand)
Gene Rel
Gene Name reticuloendotheliosis oncogene
Synonym(s) c-Rel
Chromosomal Location 23,686,847-23,720,969 bp (-) (GRCm39)
MGI Phenotype FUNCTION: [Summary is not available for the mouse gene. This summary is for the human ortholog.] This gene encodes a protein that belongs to the Rel homology domain/immunoglobulin-like fold, plexin, transcription factor (RHD/IPT) family. Members of this family regulate genes involved in apoptosis, inflammation, the immune response, and oncogenic processes. This proto-oncogene plays a role in the survival and proliferation of B lymphocytes. Mutation or amplification of this gene is associated with B-cell lymphomas, including Hodgkin's lymphoma. Single nucleotide polymorphisms in this gene are associated with susceptibility to ulcerative colitis and rheumatoid arthritis. Alternative splicing results in multiple transcript variants encoding different isoforms. [provided by RefSeq, Apr 2014]
PHENOTYPE: Homozygous inactivation of this gene causes defects in lymphocyte proliferation, humoral immunity and cytokine production, and may lead to impaired Th1 responses and resistance to autoimmune disease. Mice lacking only the COOH-terminal region show severehemopoietic defects and lymphoid hyperplasia. [provided by MGI curators]
Accession Number

NCBI RefSeq: NM_009044; MGI:97897

MappedYes 
Amino Acid Change Threonine changed to Isoleucine
Institutional SourceBeutler Lab
Gene Model predicted gene model for protein(s): [ENSMUSP00000099928]
AlphaFold no structure available at present
SMART Domains Protein: ENSMUSP00000099928
Gene: ENSMUSG00000020275
AA Change: T64I

DomainStartEndE-ValueType
Pfam:RHD_DNA_bind 10 178 8.1e-78 PFAM
IPT 185 280 7.64e-24 SMART
low complexity region 512 530 N/A INTRINSIC
Predicted Effect probably damaging

PolyPhen 2 Score 0.995 (Sensitivity: 0.68; Specificity: 0.97)
(Using ENSMUST00000102864)
Meta Mutation Damage Score 0.7378 question?
Is this an essential gene? Non Essential (E-score: 0.000) question?
Phenotypic Category Unknown
Candidate Explorer Status loading ...
Single pedigree
Linkage Analysis Data
Penetrance  
Alleles Listed at MGI

All Mutations and Alleles(8) : Chemically induced (ENU)(1)  Chemically induced (other)(1) Targeted(6)

Lab Alleles
AlleleSourceChrCoordTypePredicted EffectPPH Score
IGL00663:Rel APN 11 23707043 missense probably benign 0.31
IGL00819:Rel APN 11 23693029 missense probably benign 0.13
IGL00906:Rel APN 11 23694266 missense probably benign 0.00
IGL01358:Rel APN 11 23711155 missense probably benign 0.06
IGL01820:Rel APN 11 23703218 missense probably benign 0.22
IGL01889:Rel APN 11 23707035 missense probably damaging 0.96
IGL03270:Rel APN 11 23692584 missense probably benign 0.16
Amun-ra UTSW 11 23707026 nonsense probably null
Fleur UTSW 11 unclassified
Horus UTSW 11 23703215 critical splice donor site probably null
osirus UTSW 11 23692713 missense probably benign 0.00
Seth UTSW 11 23698855 missense probably damaging 1.00
R0766:Rel UTSW 11 23707010 missense probably damaging 1.00
R0924:Rel UTSW 11 23692439 missense probably benign 0.02
R0930:Rel UTSW 11 23692439 missense probably benign 0.02
R1312:Rel UTSW 11 23707010 missense probably damaging 1.00
R1339:Rel UTSW 11 23695763 missense probably damaging 1.00
R1584:Rel UTSW 11 23695546 missense probably damaging 1.00
R1980:Rel UTSW 11 23692761 missense probably benign
R1981:Rel UTSW 11 23692761 missense probably benign
R1982:Rel UTSW 11 23692761 missense probably benign
R2513:Rel UTSW 11 23695823 missense probably damaging 1.00
R2870:Rel UTSW 11 23711129 missense probably benign
R2870:Rel UTSW 11 23711129 missense probably benign
R2871:Rel UTSW 11 23711129 missense probably benign
R2871:Rel UTSW 11 23711129 missense probably benign
R2872:Rel UTSW 11 23711129 missense probably benign
R2872:Rel UTSW 11 23711129 missense probably benign
R3617:Rel UTSW 11 23695780 missense probably damaging 1.00
R3976:Rel UTSW 11 23692939 missense probably benign 0.07
R4010:Rel UTSW 11 23711138 missense probably benign
R4067:Rel UTSW 11 23703215 critical splice donor site probably null
R5345:Rel UTSW 11 23692462 missense probably benign 0.00
R5866:Rel UTSW 11 23692724 nonsense probably null
R6032:Rel UTSW 11 23692684 missense probably benign 0.02
R6032:Rel UTSW 11 23692684 missense probably benign 0.02
R6562:Rel UTSW 11 23707026 nonsense probably null
R6886:Rel UTSW 11 23694304 missense probably benign 0.03
R7516:Rel UTSW 11 23692785 missense probably benign 0.00
R7522:Rel UTSW 11 23720676 splice site probably null
R7663:Rel UTSW 11 23692713 missense probably benign 0.00
R7873:Rel UTSW 11 23692957 missense probably benign 0.00
R7960:Rel UTSW 11 23694493 missense probably damaging 0.98
R8679:Rel UTSW 11 23692430 missense probably benign
R8819:Rel UTSW 11 23695626 missense probably damaging 1.00
R9001:Rel UTSW 11 23698855 missense probably damaging 1.00
R9215:Rel UTSW 11 23698870 missense probably benign 0.00
Z1176:Rel UTSW 11 23695472 missense probably damaging 0.99
Mode of Inheritance Unknown
Local Stock
Repository
Last Updated 2019-09-04 9:28 PM by Anne Murray
Record Created 2019-02-08 1:06 AM by Bruce Beutler
Record Posted 2019-02-14
Phenotypic Description

Figure 1. Giza mice exhibit diminished T-independent antibody responses to 4-hydroxy-3-nitrophenylacetyl-Ficoll (NP-Ficoll). IgM levels were determined by ELISA. 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 giza phenotype was identified among G3 mice of the pedigree R1312, some of which showed diminished T-independent antibody responses to 4-hydroxy-3-nitrophenylacetyl-Ficoll (NP-Ficoll) (Figure 1).

Nature of Mutation

Figure 2. Linkage mapping of the diminished T-independent antibody responses to NP-Ficoll using a recessive model of inheritance. Manhattan plot shows -log10 P values (Y-axis) plotted against the chromosome positions of 36 mutations (X-axis) identified in the G1 male of pedigree R1312. 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 36 mutations. The diminished T-independent antibody response phenotype was linked by continuous variable mapping to mutations in two genes on chromosome 11: Rel and Vrk2. The mutation in Rel was presumed causative as the immune phenotype observed in the giza mice mimics those of other Rel mutant mouse models (see MGI). The Rel mutation is a C to T transition at base pair 23,757,010 (v38) on chromosome 11, or base pair 13,961 in the GenBank genomic region NC_000077. Linkage was found with a recessive model of inheritance, wherein three variant homozygotes departed phenotypically from 13 homozygous reference mice and 13 heterozygous mice with a P value of 0.000598 (Figure 2).  

The mutation corresponds to residue 472 in the mRNA sequence NM_009044 within exon 3 of 10 total exons.

456 GGAAAAATAAGAATTACATTAGTAACAAAGAAT
59  -G--K--I--R--I--T--L--V--T--K--N-

 

The mutated nucleotide is indicated in red. The mutation results in a threonine to isoleucine substitution at position 64 (T64I) in the c-Rel protein, and is strongly predicted by Polyphen-2 to cause loss of function (score = 0.995).

Illustration of Mutations in
Gene & Protein
Protein Prediction

Figure 3. The domain organization of c-Rel. The location of the giza mutation is indicated. c-Rel has a Rel-homology domain (RHD), which includes a DNA binding domain and a dimerization domain (DimD). The nuclear localization sequence (NLS) is indicated. The transactivation domain (TAD) has two subdomains: I and II. This image is interactive; click on the other mutations to view additional information.

Rel encodes c-Rel, a member of the NF-κB family of transcription factors, which also includes RelA (p65), RelB, NF-κB1 (p105/p50; see the record for Finlay), and NF-κB2 (p100/p52; see the record for xander). The NF-κB protein family members are characterized by the presence of an N-terminal Rel homology domain (RHD) (Figure 3). The RHD (amino acids 8-297, UniProt) is comprised of the N-terminal domain, the dimerization domain (DimD), and a nuclear localization sequence (amino acids 291-296) that mediate sequence-specific DNA binding, nuclear localization, interaction with IκB, and homo- and heterodimerization [reviewed in (1)]. RelA, RelB, and c-Rel have a transactivation domain (TAD) that allows for direct control of transcription (2). Within the TAD are two subdomains: subdomains I and II at amino acids 424-490 and 518-587, respectively. A Rel inhibitory domain (RID) acts as a hinge between the RHD and TAD.

The giza mutation results in a threonine to isoleucine substitution at position 64 (T64I); amino acid 64 is within the DNA-binding RHD.

Please see the record horus for more information about Rel.

Putative Mechanism

NF-κB controls the proliferation, differentiation and survival of B and T cells. In the nucleus, NF-κB acts as a transcription factor that regulates the expression of genes encoding a variety of immune response genes including pro-inflammatory cytokines (e.g., TNFα (see the record for PanR1), IL-1, and IL-6), chemokines [e.g., MIP-1α (macrophage inflammatory protein-1α), and RANTES (regulated upon activation, normal T-cell expressed and secreted)], cell adhesion molecules [e.g., E-selectin and VCAM-1 (vascular cell adhesion molecule-1)], effector molecules [e.g., defensins], enzymes [e.g., inducible nitric oxide synthase], and growth factors to regulate the recruitment of immune cells to the site of infection [(3;4); reviewed in (5)]. Inhibition of NF-κB leads to apoptosis [through the misregulation of anti-apoptotic proteins (e.g., c-IAP-1/2, AI, Bcl-2 and Bcl-XL)], delayed cell growth, reduced cell proliferation [through negative regulation of cell cycle regulator cyclin D1 (6)] and incorrect immune cell development [reviewed in (7-9)].

c-Rel is essential for normal B and T cell activation and proliferation. In addition, c-Rel is essential for the prevention of autoimmunity. Outside of the immune system, c-Rel maintains organ homeostasis and the cell cycle under conditions of stress or damage. In addition, it is essential for long-term memory consolidation and promotes neuronal survival upon hypoxic stress.

c-Rel is required for BCR-mediated proliferation and cell cycle progression (10). c-Rel is essential for germinal center and memory B cell differentiation as well as for anti-IgM- and LPS-induced survival and cell cycle progression (11). c-Rel mediates the proliferation, differentiation, and cytokine production of stimulated T cells (12). c-Rel is required for antigen-induced activation of mature T cells (13). However, c-Rel is not required for positive selection during T cell development or for apoptosis of T lymphocytes. c-Rel maintains the balance between Th1, Th17, and Treg cells to regulate innate immune responses (14-17).

Rel deficient (Rel-/-) mice are overtly normal and have a structurally normal immune system (11;12). However, the Rel-/- mice exhibited immunological defects including reduced lymphocyte proliferation and activation (18). Rel-/- mice did not exhibit defects in the maturation of hematopoietic precursors, including B and T lymphocytes, macrophages, and neutrophils (18). The frequency of monocytes was normal (19). Rel-/- mice display reduced expression of IL-2, IL-3, IL-6, IL-10, IL-13, IL-15, IL-21, IFNγ, MIP1α, and GM-CSF (12;19). C-Rel is required for optimal development of humoral immunity (20). After influenza virus infection, Rel-/- mice exhibited normal levels of virus-specific cytotoxic T cells. However, they exhibited reduced T cell proliferative responses to the virus as well as diminished local and systemic influenza virus-specific antibody responses. Vaccinated mice were unable to acquire antibody-dependent protective immunity to reinfection.

Rel-/- mice exhibit normal early lymphocyte development, but have fewer memory (IgM / IgD) B cells (11). B cells from the Rel-/- mice exhibited impaired proliferation in response to antigen receptor cross-linking and mitogenic activation (e.g., lipopolysaccharide (LPS), anti-IgM, antigen, or CD40) (18;20;21). Although the Rel-/- B cells exhibited normal CD40-associated cell survival, the Rel-/- B cells were unable to receive anti-IgM- or LPS-generated survival signals (11). B cells from the Rel-/- mice were more susceptible to apoptotic stimuli (11;22;23).  In resting Rel-/- B cells, BCR stimulation did not induce proper cyclin D3 and cyclin E expression, subsequently negatively regulating G1 cyclin-dependent kinase activity. The Rel-/- B cells were able to exit the G0 phase and enter the G1 phase phases after stimulation with anti-IgM or LPS, but transition from the G1 to S phase was impaired (11;24). In addition, the proliferation defects in the Rel-/- B cells were attributed to a loss of c-Rel binding to the pro-proliferative protein IRF-4 (25). C-Rel was also found to control the expression of the anti-apoptotic protein, Bcl-2, and of A1, a homolog of Bcl-2, leading to increased rates of apoptosis in the Rel-/- B cells (22;24).  Rel-/- mice have irregular germinal centers (GCs) and a reduced frequency of marginal zone B cells (26;27). The Rel-/- mice establish fewer B cells with a germinal center (PNAhi) phenotype after immunization (11).

The phenotypes observed in the giza mice indicate loss of c-Rel-associated function in B and T cells.

Primers PCR Primer
giza_pcr_F: TCCTCCCCACAGGTAACAAAGTGT
giza_pcr_R: caccataatgcctggcCTGCTTA

Sequencing Primer
giza_seq_F: AACAAAGGTCTGCGTTCTGG
giza_seq_R: aggggcattattgtaggtagc
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 682 nucleotides is amplified (chromosome 11, - strand):


1   caccataatg cctggcctgc ttacctgctt taaaaggaaa ataaacagat gataaagcta
61  gataaaataa gggcagaaag aaacatttta ggaattgaaa gataagtttt cccagctgat
121 atattctctg aaaactttaa tctcaagtaa actgctgact atttgaattt tattgcatgc
181 tgactacatt atataaattg aacttaaatt aatggatcaa ttctttttat ttgtttgctt
241 tttaaaaggg gcattattgt aggtagccct ggctggcctt gaacttgtgc tgatcctgct
301 cagccttcca aatgctgggg ctataggcat atgctacaat acctacctat tgttaacaag
361 atatacatac agactgtata tttaatttcc cttttcagat tatgaactac tatggaaaag
421 gaaaaataag aattacatta gtaacaaaga atgatccata taagcctcat cctcatgatt
481 tagttggaaa agattgcaga gatggatact atgaagcaga atttggacca gaacgcagac
541 ctttgttgta agtatacagt gacagaaacc ttcagcaata ggacaaagat ataattttag
601 tttatagcaa aataattctg tatttaactt actgtaacat gtacattaca ttttaattac
661 actttgttac ctgtggggag ga


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

References
Science Writers Anne Murray
Illustrators Diantha La Vine
AuthorsJin Huk Choi, Xue Zhong, and Bruce Beutler