Phenotypic Mutation 'artemis' (pdf version)
Alleleartemis
Mutation Type missense
Chromosome10
Coordinate70,863,784 bp (GRCm39)
Base Change G ⇒ A (forward strand)
Gene Bicc1
Gene Name BicC family RNA binding protein 1
Synonym(s) Bic-C, jcpk
Chromosomal Location 70,758,662-70,995,530 bp (-) (GRCm39)
MGI Phenotype FUNCTION: [Summary is not available for the mouse gene. This summary is for the human ortholog.] This gene encodes an RNA-binding protein that is active in regulating gene expression by modulating protein translation during embryonic development. Mouse studies identified the corresponding protein to be under strict control during cell differentiation and to be a maternally provided gene product. [provided by RefSeq, Apr 2009]
PHENOTYPE: Homozygous inactivation of this gene causes heteroxia, impaired nodal flow, ventricular septal defects, partial prenatal lethality and postnatal death due to renal failure. Chemically induced mutants develop kidney cysts and may show bulging abdomens, bile duct anomalies and cardiovascular defects. [provided by MGI curators]
Accession Number

NCBI RefSeq: NM_031397; MGI: 1933388

MappedYes 
Amino Acid Change Threonine changed to Isoleucine
Institutional SourceBeutler Lab
Gene Model not available
AlphaFold Q99MQ1
SMART Domains Protein: ENSMUSP00000014473
Gene: ENSMUSG00000014329
AA Change: T86I

DomainStartEndE-ValueType
KH 47 129 2.69e0 SMART
KH 133 206 6.24e-18 SMART
KH 285 355 1.25e-8 SMART
low complexity region 384 402 N/A INTRINSIC
low complexity region 447 467 N/A INTRINSIC
low complexity region 480 499 N/A INTRINSIC
low complexity region 700 718 N/A INTRINSIC
low complexity region 736 747 N/A INTRINSIC
low complexity region 794 815 N/A INTRINSIC
SAM 872 938 2.04e-9 SMART
Predicted Effect possibly damaging

PolyPhen 2 Score 0.953 (Sensitivity: 0.79; Specificity: 0.95)
(Using ENSMUST00000014473)
SMART Domains Protein: ENSMUSP00000119137
Gene: ENSMUSG00000014329
AA Change: T4I

DomainStartEndE-ValueType
SCOP:d1dtja_ 1 46 1e-2 SMART
Blast:KH 1 47 1e-22 BLAST
KH 51 124 6.24e-18 SMART
KH 203 273 1.25e-8 SMART
low complexity region 302 320 N/A INTRINSIC
low complexity region 365 385 N/A INTRINSIC
low complexity region 398 417 N/A INTRINSIC
low complexity region 618 636 N/A INTRINSIC
low complexity region 654 665 N/A INTRINSIC
low complexity region 712 733 N/A INTRINSIC
SAM 790 856 2.04e-9 SMART
Predicted Effect possibly damaging

PolyPhen 2 Score 0.953 (Sensitivity: 0.79; Specificity: 0.95)
(Using ENSMUST00000131445)
SMART Domains Protein: ENSMUSP00000123201
Gene: ENSMUSG00000014329
AA Change: T86I

DomainStartEndE-ValueType
KH 47 129 2.69e0 SMART
KH 133 206 6.24e-18 SMART
KH 285 355 1.25e-8 SMART
low complexity region 384 402 N/A INTRINSIC
low complexity region 447 467 N/A INTRINSIC
low complexity region 480 499 N/A INTRINSIC
low complexity region 700 718 N/A INTRINSIC
low complexity region 736 747 N/A INTRINSIC
low complexity region 794 815 N/A INTRINSIC
SAM 872 938 4.26e-12 SMART
Predicted Effect probably damaging

PolyPhen 2 Score 0.994 (Sensitivity: 0.69; Specificity: 0.97)
(Using ENSMUST00000143791)
Meta Mutation Damage Score Not available question?
Is this an essential gene? Essential (E-score: 1.000) question?
Phenotypic Category Autosomal Recessive
Candidate Explorer Status loading ...
Single pedigree
Linkage Analysis Data
Penetrance 100% 
Alleles Listed at MGI

All alleles(5) : Targeted, knock-out(1) Targeted, other(1) Spontaneous(1) Chemically induced(2)

Lab Alleles
AlleleSourceChrCoordTypePredicted EffectPPH Score
IGL00961:Bicc1 APN 10 70796987 missense probably damaging 1.00
IGL01988:Bicc1 APN 10 70792006 missense probably damaging 1.00
IGL02686:Bicc1 APN 10 70779190 splice site probably benign
IGL02829:Bicc1 APN 10 70794710 missense probably damaging 1.00
IGL03276:Bicc1 APN 10 70789268 missense possibly damaging 0.76
IGL03354:Bicc1 APN 10 70782432 missense probably benign 0.00
Pebbles UTSW 10 70783730 missense possibly damaging 0.95
PIT1430001:Bicc1 UTSW 10 70793511 missense possibly damaging 0.94
R0095:Bicc1 UTSW 10 70796988 missense probably damaging 1.00
R0142:Bicc1 UTSW 10 70761200 missense probably damaging 1.00
R0184:Bicc1 UTSW 10 70915045 missense probably benign
R0469:Bicc1 UTSW 10 70915045 missense probably benign
R0485:Bicc1 UTSW 10 70761145 missense probably damaging 0.96
R0520:Bicc1 UTSW 10 70793020 missense probably damaging 0.96
R0884:Bicc1 UTSW 10 70794677 missense probably damaging 1.00
R1678:Bicc1 UTSW 10 70779348 missense probably damaging 1.00
R1892:Bicc1 UTSW 10 70794614 missense probably damaging 1.00
R1943:Bicc1 UTSW 10 70995353 missense probably damaging 1.00
R2220:Bicc1 UTSW 10 70785955 missense probably damaging 1.00
R2240:Bicc1 UTSW 10 70782633 critical splice donor site probably null
R2519:Bicc1 UTSW 10 70766474 missense probably damaging 1.00
R4362:Bicc1 UTSW 10 70779204 frame shift probably null
R4363:Bicc1 UTSW 10 70779204 frame shift probably null
R4419:Bicc1 UTSW 10 70782804 missense possibly damaging 0.73
R4697:Bicc1 UTSW 10 70789314 missense possibly damaging 0.87
R4728:Bicc1 UTSW 10 70771661 critical splice donor site probably null
R4765:Bicc1 UTSW 10 70776423 missense probably damaging 1.00
R4838:Bicc1 UTSW 10 70781146 missense possibly damaging 0.50
R5022:Bicc1 UTSW 10 70783713 missense possibly damaging 0.79
R5023:Bicc1 UTSW 10 70783713 missense possibly damaging 0.79
R5057:Bicc1 UTSW 10 70783713 missense possibly damaging 0.79
R5082:Bicc1 UTSW 10 70776352 missense probably benign 0.05
R5160:Bicc1 UTSW 10 70768066 missense probably damaging 1.00
R5294:Bicc1 UTSW 10 70783730 missense possibly damaging 0.95
R5639:Bicc1 UTSW 10 70776350 missense probably damaging 1.00
R5749:Bicc1 UTSW 10 70782799 missense probably benign 0.00
R6045:Bicc1 UTSW 10 70792911 nonsense probably null
R6128:Bicc1 UTSW 10 70776313 splice site probably null
R6277:Bicc1 UTSW 10 70863731 missense possibly damaging 0.74
R6389:Bicc1 UTSW 10 70794752 missense probably damaging 1.00
R7021:Bicc1 UTSW 10 70796978 missense probably damaging 0.99
R7101:Bicc1 UTSW 10 70766483 missense probably damaging 1.00
R7351:Bicc1 UTSW 10 70783730 missense probably benign 0.18
R7352:Bicc1 UTSW 10 70783730 missense probably benign 0.18
R7353:Bicc1 UTSW 10 70783730 missense probably benign 0.18
R7366:Bicc1 UTSW 10 70779216 missense probably benign 0.01
R7480:Bicc1 UTSW 10 70779306 missense probably damaging 1.00
R7541:Bicc1 UTSW 10 70782434 missense possibly damaging 0.82
R7544:Bicc1 UTSW 10 70792204 missense possibly damaging 0.89
R7555:Bicc1 UTSW 10 70792121 missense possibly damaging 0.75
R7663:Bicc1 UTSW 10 70782420 missense probably benign
R7671:Bicc1 UTSW 10 70792997 missense probably benign 0.01
R7747:Bicc1 UTSW 10 70782823 missense probably benign
R8129:Bicc1 UTSW 10 70915033 missense probably benign 0.01
R8270:Bicc1 UTSW 10 70767938 missense probably damaging 0.99
R8525:Bicc1 UTSW 10 70779365 missense possibly damaging 0.67
R8762:Bicc1 UTSW 10 70779216 missense probably benign 0.03
R8849:Bicc1 UTSW 10 70782694 missense probably benign 0.23
R9120:Bicc1 UTSW 10 70776862 missense probably damaging 1.00
R9164:Bicc1 UTSW 10 70781094 missense probably damaging 1.00
R9368:Bicc1 UTSW 10 70785917 missense probably benign 0.13
R9452:Bicc1 UTSW 10 70792981 missense probably damaging 0.99
R9497:Bicc1 UTSW 10 70776828 critical splice donor site probably null
R9641:Bicc1 UTSW 10 70863772 missense probably benign 0.01
R9672:Bicc1 UTSW 10 70794666 missense probably damaging 1.00
RF013:Bicc1 UTSW 10 70771660 critical splice donor site probably null
X0028:Bicc1 UTSW 10 70781166 missense probably damaging 1.00
Mode of Inheritance Autosomal Recessive
Local Stock Embryos, Sperm, gDNA
MMRRC Submission 030203-MU
Last Updated 2016-05-13 3:09 PM by Stephen Lyon
Record Created unknown
Record Posted 2011-08-29
Phenotypic Description
The artemis phenotype was identified among ENU-mutagenized G3 mice when several animals from one pedigree were unexpectedly found dead. Upon analysis, the mice were found to have drastically enlarged kidneys. The phenotype segregated in a recessive Mendelian inheritance pattern, and was designated artemis. Artemis mice have enlarged polycystic kidneys, observable by 1 week of age. Urea levels are increased 5-fold in blood from artemis mice.
 
Homozygote artemis mice are viable but infertile. Heterozygotes are viable and fertile.
Nature of Mutation
The artemis mutation mapped to Chromosome 10, and corresponds to a C to T transition at position 275 of the Bicc1 transcript, in exon 3 of 21 total exons.
 
259 AAGATCATGGAGGAGACACAGATTGCA
81  -M--E--E--T--N--T--Q--I--A-
 
The mutated nucleotide is indicated in red lettering, and causes a threonine to isoleucine substitution at residue 86 of the Bicc1 protein.
Illustration of Mutations in
Gene & Protein
Protein Prediction
Figure 1. Domain structure of Bicc1 protein products encoded by two alternatively spliced transcripts. The shorter transcript lacks exon 21, which results in deletion of 26 amino acids, including the last three residues of the SAM domain. The artemis mutation lies within the first KH domain.
Bicc1 encodes two alternatively spliced transcripts which differ by the presence or absence of the 80-nucleotide exon 21, and are predicted to result in proteins of 977 or 951 amino acids, respectively (Figure 2) (1). Bicc1 contains three predicted K homology (KH) RNA-binding domains near the N terminus, and one sterile alpha motif (SAM) protein interaction domain near the C terminus (1;2). The SAM domain in the shorter transcript is predicted to lack the last three C-terminal amino acids of the complete SAM domain consensus sequence due to alternative splicing, but whether this affects protein function is unknown (1).
 
The artemis mutation results in a threonine to isoleucine at position 86 of Bicc1, which resides in the N-terminal KH domain. This mutation is predicted to disrupt Bicc1 RNA-binding ability and/or destabilize the protein.  Protein expression levels have not been examined in artemis tissue.
Expression/Localization

Bicc1mRNA is detected in mouse embryos as soon as they have implanted, and is observed at embryonic day 13 around sites of cartilage formation, in the presumptive diaphragm, pericardium, in the mesenchyme of the developing lung, and in the mesonephros and metanephros of the developing kidney (2). Total levels of Bicc1 mRNA in whole embryos increase slightly as embryogenesis proceeds (1). In the adult mouse, Bicc1 transcripts are found at high levels in the heart and kidney, with lower levels expressed in the testis (1;2). Bicc1 mRNA can also be detected in the stroma of primary oocytes, suggesting a maternal Bicc1 contribution exists in the mouse (2), in agreement with the finding that Drosophila Bicaudal-C is a maternal effect gene (3).

In mouse inner medullary collecting duct cells, Bicc1 displays a diffuse cytoplasmic localization (4).

Background

bicaudal(bic) was first identified as a genetic factor affecting the anterior-posterior polarity of Drosophila embryos (5). The progeny of homozygous bic mutant female flies sometimes develop without structures from the anterior end of the embryo or with a double-abdomen, with two posterior ends arranged in mirror-image symmetry (3;5). Thus, bicaudal is a maternal effect gene with an incompletely penetrant phenotype. Subsequent genetic screening identified several new distinct loci causing similar defects in anterior-posterior patterning, one of which encoded the dominant maternal-effect mutation, Bicaudal-C (Bic-c) (3).

Mislocalization of pattern-determining RNAs, such as oskar (osk) and nanos (nos), during embryogenesis results in bicaudal embryos with posterior structures duplicated at their anterior ends (6;7). In progeny of Bic-C mutant females, the posterior determinant osk is mislocalized at the anterior of the embryos, suggesting that Bic-C functions to localize specific posterior RNAs during oogenesis (8). This is supported by data indicating that Bic-C protein (BIC-C) contains 5 KH domains (8) which allow it to bind RNA (9). Furthermore, at least one of its KH domains is required for its function, as a point mutation in the third KH domain causes a strong bicaudal phenotype (8). BIC-C also regulates osk translation (9).

The murine homologue of Bic-c (Bicc1 in mice) was identified by homology searches of cDNA sequences in GenBank (2), and later found to be the gene mutated to cause polycystic kidney disease in two mouse mutants (1). These two mouse strains have different mutant alleles of Bicc1, called jcpk and bpk. The jcpk allele was generated on a C57BL/6 background by random chlorambucil-induced mutagenesis (10;11), while the bpk allele arose spontaneously in the BALB/c strain (12). Homozygous jcpk mutants die before 10 days of age with numerous cysts in the kidneys, including in the proximal and distal tubules, collecting ducts and glomeruli (11). jcpk mutants display dilation of liver and pancreatic ducts. Approximately 30% of heterozygous jcpk mice also develop late-onset polycystic kidney disease affecting the glomeruli (11). In contrast, bpk mutants display a less severe phenotype distinct from that of jcpk mice, with polycystic kidneys that show dilation of the renal collecting ducts, and biliary dysgenesis (13;14). bpk mice live to approximately 4 weeks of age (13;14).  Mouse embryos with a targeted deficiency of Bicc1 were reported to display randomized left-right asymmetry due to disruption of the planar alignment of motile cilia of the ventral node.  Interestingly, polycystic kidney disease is also frequently linked to cilia defects, as for example in mice with mutations of Pkhd1 and inversin (15;16).

Autosomal recessive polycystic kidney disease (ARPKD) is an inherited disease occurring in 1 in 20,000 humans (17), characterized by dilation of renal collecting ducts, biliary dysgenesis, and portal tract fibrosis (18). The PKHD1 gene has recently been identified as the principal causative disease gene (19). Before its identification, jcpk, bpk and several other mutants have been used as models to investigate the pathogenesis of ARPKD.

Putative Mechanism

Primary apical cilia are present on epithelial cells of the nephron, biliary tract, and pancreatic ducts during adulthood (20).  The association of polycystic kidney disease with deficiencies of cilium proteins including Pkhd1, inversin, and Tg737 (21;22) in mice suggests that dysfunction of cilia may underlie cyst formation.  Although immortalized renal cells from Bicc1bpk mutants were reported to display normal ciliogenesis (23), their function was not examined.

Figure 2. Hypothesized role of Bicc1 in the regulation of polarity of renal epithelial cells.  Bicc1-deficient cells display aberrant localization of EGFR (from the basolateral to the apical cell membrane) and E-cadherin (from the cell membrane to the cytoplasm), conditions that may lead to impaired epithelial polarization.  Bicc1 and SamCystin were reported to interact through at least one unidentified protein and one RNA species; whether and how this complex controls EGFR and E-cadherin localization remains known.

Several reports suggest that mutations in Bicc1 cause polycystic kidneys by disrupting the normal polarity of renal epithelial cells.  In cystic renal cells immortalized from the bpk mutant mouse, epidermal growth factor receptor (EGFR) was aberrantly localized to the apical cell membrane (Figure 2), in addition to its normal presence at the basolateral membrane (23).  Abnormal EGFR sorting to the apical membrane has been observed in polycystic kidney disease caused by mutations in PKD1, PKD2, and PKHD1 (24;25).  In addition, EGFR ligands have been detected in the apical medium of cultured cystic epithelial cells and in the cyst fluid of autosomal dominant polycystic kidney disease (ADPKD) patients (26).  EGFR kinase inhibition improves kidney function in models of polycystic kidney disease (27).

In mouse inner medullary collecting duct cell lines in which Bicc1 was silenced by short hairpin RNA inhibition (shRNA), E-cadherin was mislocalized from cell-cell junctions to the cytoplasm (28).  Impaired cell motility, tubulogenesis, and actin cytoskeletal organization were attributed to defective E-cadherin-dependent cell-cell adhesion in these cells.  E-cadherin-mediated cell-cell adhesion triggers assembly of intercellular junctions, and is therefore essential for epithelial polarity and tubule formation.

The mechanism by which Bicc1 affects EGFR and E-cadherin localization remains unknown.  A report documents interaction between Bicc1 and SamCystin, another SAM-containing protein, through an unidentified RNA molecule (4).  Further studies should reveal whether the Bicc1-SamCystin complex controls EGFR and E-cadherin localization (Figure 2).

Primers Primers cannot be located by automatic search.
Genotyping
Artemis 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
Bicc1(F): 5’-TCTGATGGTCCTGGCAACAAGC-3’
Bicc1(R): 5’-ACAGGTTACTGTGAAGCCCGTTATG-3’
 
PCR program
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) 35X
6) 72°C             5:00
7) 4°C              ∞
 
Primers for sequencing
Bicc1_seq(F): 5’- TTTGAACGTGTGAAAATCTTATCTGT-3’
Bicc1_seq(R): 5’- CCAAACGTGAACAGAACTGAGCTC-3’
 
The following sequence of 618 nucleotides (from Genbank genomic region NC_000076 for linear DNA sequence of Bicc1) is amplified:
 
131345     tctgat ggtcctggca acaagctggg ttaattactt gtccatgtac tttgaggtct
131401 tgtttctgtt aagattctgg attcacggag agaacaacac agacttggat gctctcagta
131461 gattaagggc ttaggaaaac acaccccctc ttctccctcg agctttcaaa aagatgtttg
131521 cattgtttta agctgagatc atcttgttgt atcaacacaa agccagaaac atgaaaataa
131581 gaattttttt tttgaacgtg tgaaaatctt atctgtaaat acaagttctt aattgagtca
131641 atatttttct cttgatccct gactcagatc atggaggaga caaacacgca gattgcatgg
131701 ccgtccaaac tgaagatcgg ggctaaatcc aagaaaggta aatttgggac ggggagtagg
131761 tatgtttgaa aaacgagctt ccggggttgc tggagctcag ttctgttcac gtttggcctc
131821 aagtgcttgt caaatagccg tatttgggga ggattttcat gattaaaata aataggtggc
131881 tttgtggcag cagaaaaaaa aatgcttaaa aaaatagtat taaaatagaa atgttaccat
131941 aacgggcttc acagtaacct gt
 
PCR primer binding sites are underlined; sequencing primer binding sites are highlighted in gray; the mutated C is shown in red text.
References
Science Writers Eva Marie Y. Moresco
Illustrators Diantha La Vine
AuthorsMichael J. Barnes, Amanda L. Blasius, Bruce Beutler
Edit History
2011-08-30 11:20 AM (current)
2011-08-29 6:39 PM
2011-04-18 4:35 PM
2011-01-07 8:50 AM
2010-10-08 2:21 PM
2010-10-08 2:21 PM
2010-02-11 9:42 AM