|Mutation Type||critical splice donor site (1 bp from exon)|
|Coordinate||96,150,797 bp (GRCm38)|
|Base Change||G ⇒ A (forward strand)|
|Gene Name||glycerol kinase 5 (putative)|
|Chromosomal Location||96,119,362-96,184,608 bp (+)|
|MGI Phenotype||PHENOTYPE: Homozygous knockout does not result in an obvious skin phenotype and does not lead to alopecia. [provided by MGI curators]|
|Amino Acid Change|
|Institutional Source||Beutler Lab|
|Gene Model||predicted gene model for protein(s): [ENSMUSP00000082313 †] [ENSMUSP00000112717 †] [ENSMUSP00000123594 †] † probably from a misspliced transcript|
|Predicted Effect||probably null|
|Predicted Effect||probably null|
|Predicted Effect||probably benign|
|Meta Mutation Damage Score||0.702|
|Is this an essential gene?||Non Essential (E-score: 0.000)|
|Candidate Explorer Status||CE: excellent candidate; human score: 2; ML prob: 0.8264|
Linkage Analysis Data
|Alleles Listed at MGI|
|Mode of Inheritance||Autosomal Recessive|
|Last Updated||2019-09-04 9:46 PM by Anne Murray|
|Record Created||2015-03-11 12:15 PM by Zhao Zhang|
The tangyuan phenotype was identified among N-ethyl-N-nitrosourea (ENU)-mutagenized G3 mice of the pedigree R1772, some of which showed hair loss (Figure 1). Some mice also showed increased frequencies of CD44+ CD8 T cells (Figure 2) and central memory CD8 T cells in CD8 T cells (Figure 3) in the peripheral blood. The expression of CD44 was increased on peripheral blood CD8 T cells (Figure 4).
|Nature of Mutation|
Whole exome HiSeq sequencing of the G1 grandsire identified 114 mutations. Among these, only one affected a gene with known effects on hair loss, Gk5. The mutation in Gk5 was presumed to be causative because the tangyuan hair loss phenotype mimics other known alleles of Gk5 (see the entries for toku and barrener). The Gk5 mutation is a G to A transition at base pair 96,150,797 (v38) on chromosome 9, or base pair 31,454 in the GenBank genomic region NC_000075 in the donor splice site of intron 9. The strongest association was found with a recessive model of inheritance to the normalized frequency of CD44+ CD8 T cells, wherein two variant homozygotes departed phenotypically from three homozygous reference mice and 13 heterozygous mice with a P value of 1.953 x 10-5 (Figure 5).
The effect of the mutation at the cDNA and protein level have not examined, but the mutation is predicted to result in skipping of the 61-nucleotide exon 9 (out of 16 total exons), resulting in a frame shifted protein product beginning after amino acid 256 of the protein and terminating after the inclusion of 19 aberrant amino acids.
Genomic numbering corresponds to NC_000075. The donor splice site of intron 9, which is destroyed by the tangyuan mutation, is indicated in blue lettering and the mutated nucleotide is indicated in red.
The glycerol kinase 5 (putative) (Gk5) gene encodes the 534 amino acid (aa) GK5 protein. The protein domains and function of GK5 have not been documented. SMART predicts that this uncharacterized protein contains two domains that are found in the FGGY family of carbohydrate kinases. The FGGY kinases contain conserved motifs at both the N- and C-termini (Figure 6; aa 25-287 and aa 396-416 in GK5, respectively; SMART). The FGGY_N and FGGY_C termini are structurally similar and adopt a ribonuclease H-like fold (1;2). Between the FGGY_N and FGGY_C domains is a catalytic cleft where the sugar substrate and ATP bind (3). The tangyuan mutation is predicted to result in skipping of exon 9, resulting in a frame shifted protein product beginning after amino acid 256 of the protein and terminating after the inclusion of 19 aberrant amino acids.
For more information about Gk5, please see the entry for toku.
The over 4,000 members of the FGGY family phosphorylate sugar substrates in an ATP-dependent manner (3). Similar to glycerol kinase, GK5 is proposed to be involved in ATP binding, phosphotransferase activity, and glycerol kinase activity. GK5 is necessary for hair growth, and functions in the regulation of SREBP-1/-2-mediated cholesterol production in the skin (4). The buildup of sterol precursors in the sebocytes results in defects in hair follicle development and homeostasis as observed in the tangyuan mice (4).
1) 94°C 2:00
The following sequence of 649 nucleotides is amplified (chromosome 9, + strand):
1 actttatggg ctacgcgaaa agcagtttgc cggattttag ggtgagtgcg tccagagcta
Primer binding sites are underlined and the sequencing primers are highlighted; the mutated nucleotide is shown in red.
1. Hurley, J. H., Faber, H. R., Worthylake, D., Meadow, N. D., Roseman, S., Pettigrew, D. W., and Remington, S. J. (1993) Structure of the Regulatory Complex of Escherichia Coli IIIGlc with Glycerol Kinase. Science. 259, 673-677.
2. Ormo, M., Bystrom, C. E., and Remington, S. J. (1998) Crystal Structure of a Complex of Escherichia Coli Glycerol Kinase and an Allosteric Effector Fructose 1,6-Bisphosphate. Biochemistry. 37, 16565-16572.
3. Zhang, Y., Zagnitko, O., Rodionova, I., Osterman, A., and Godzik, A. (2011) The FGGY Carbohydrate Kinase Family: Insights into the Evolution of Functional Specificities. PLoS Comput Biol. 7, e1002318.
4. 1. Zhang, D., Tomisato, W., Su, L., Sun, L., Choi, J. H., Zhang, Z., Wang, K., Zhan, X., Choi, M., Li, X., Castro-Perez, J. M., Hildebrand, S., Murray, A. R., Moresco, E. M. Y., and Beutler, B. (2017) Skin-Specific Regulation of SREBP Processing and Lipid Biosynthesis by Glycerol Kinase 5. Proc Natl Acad Sci USA. 114, E5197-E5206.
|Science Writers||Anne Murray|
|Authors||Zhao Zhang, Doan Dao, Hexin Shi, Lei Sun, Jianhui Wang, Ying Wang, Bruce Beutler|