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UniProtKB/Swiss-Prot Q09013: Variant p.Leu423Val

Myotonin-protein kinase
Gene: DMPK
Variant information

Variant position:  423
The position of the amino-acid change on the UniProtKB canonical protein sequence.

Type of variant:  Polymorphism
The variants are classified into three categories: Disease, Polymorphism and Unclassified.
  • Disease: Variants implicated in disease according to literature reports.
  • Polymorphism: Variants not reported to be implicated in disease.
  • Unclassified: Variants with uncertain implication in disease according to literature reports. Evidence against or in favor of a pathogenic role is limited and/or conflicting.

Residue change:  From Leucine (L) to Valine (V) at position 423 (L423V, p.Leu423Val).
Indicates the amino acid change of the variant. The one-letter and three-letter codes for amino acids used in UniProtKB/Swiss-Prot are those adopted by the commission on Biochemical Nomenclature of the IUPAC-IUB.

Physico-chemical properties:  Similar physico-chemical property. Both residues are medium size and hydrophobic.
The physico-chemical property of the reference and variant residues and the change implicated.

BLOSUM score:  1
The score within a Blosum matrix for the corresponding wild-type to variant amino acid change. The log-odds score measures the logarithm for the ratio of the likelihood of two amino acids appearing by chance. The Blosum62 substitution matrix is used. This substitution matrix contains scores for all possible exchanges of one amino acid with another:
  • Lowest score: -4 (low probability of substitution).
  • Highest score: 11 (high probability of substitution).
More information can be found on the following page

Other resources:  
Links to websites of interest for the variant.



Sequence information

Variant position:  423
The position of the amino-acid change on the UniProtKB canonical protein sequence.

Protein sequence length:  629
The length of the canonical sequence.

Location on the sequence:   YSYSCMALRDSEVPGPTPME  L EAEQLLEPHVQAPSLEPSVS
The residue change on the sequence. Unless the variant is located at the beginning or at the end of the protein sequence, both residues upstream (20) and downstream (20) of the variant will be shown.

Residue conservation: 
The multiple alignment of the region surrounding the variant against various orthologous sequences.

Human                         YSYSCMALRDSEVPGPTPMELEAEQLLEPHVQAPSLEPSVS

Mouse                         YSYCCMAFRDNQVPDPTPMELEALQLPVSDLQGLDLQPPVS

Sequence annotation in neighborhood:  
The regions or sites of interest surrounding the variant. In general the features listed are posttranslational modifications, binding sites, enzyme active sites, local secondary structure or other characteristics reported in the cited references. The "Sequence annotation in neighborhood" lines have a fixed format:
  • Type: the type of sequence feature.
  • Positions: endpoints of the sequence feature.
  • Description: contains additional information about the feature.

TypePositionsDescription
Chain 1 – 629 Myotonin-protein kinase
Topological domain 1 – 590 Cytoplasmic


Literature citations

Genomic organization and transcriptional units at the myotonic dystrophy locus.
Shaw D.J.; McCurrach M.; Rundle S.A.; Harley H.G.; Crow S.R.; Sohn R.; Thirion J.-P.; Hamshere M.G.; Buckler A.J.; Harper P.S.; Housman D.E.; Brook J.D.;
Genomics 18:673-679(1993)
Cited for: NUCLEOTIDE SEQUENCE [GENOMIC DNA / MRNA] (ISOFORM 2); VARIANT VAL-423;

Structure and genomic sequence of the myotonic dystrophy (DM kinase) gene.
Mahadevan M.S.; Amemiya C.; Jansen G.; Sabourin L.; Baird S.; Neville C.E.; Wormskamp N.; Segers B.; Batzer M.; Lamerdin J.; de Jong P.J.; Wieringa B.; Korneluk R.G.;
Hum. Mol. Genet. 2:299-304(1993)
Cited for: NUCLEOTIDE SEQUENCE [GENOMIC DNA] (ISOFORMS 1; 2; 5; 6); VARIANT VAL-423;

Decreased expression of myotonin-protein kinase messenger RNA and protein in adult form of myotonic dystrophy.
Fu Y.-H.; Friedman D.L.; Richards S.; Pearlman J.A.; Gibbs R.A.; Pizzuti A.; Ashizawa T.; Perryman M.B.; Scarlato G.; Fenwick R.G. Jr.; Caskey C.T.;
Science 260:235-238(1993)
Cited for: NUCLEOTIDE SEQUENCE [GENOMIC DNA] (ISOFORMS 7; 8; 9; 10; 11 AND 12); VARIANT VAL-423;

Molecular basis of myotonic dystrophy: expansion of a trinucleotide (CTG) repeat at the 3' end of a transcript encoding a protein kinase family member.
Brook J.D.; McCurrach M.; Harley H.G.; Buckler A.J.; Church D.; Aburatani H.; Hunter K.; Stanton V.P.; Thirion J.-P.; Hudson T.; Sohn R.; Zemelman B.; Snell R.G.; Rundle S.A.; Crow S.; Davies J.; Shelbourne P.; Buxton J.; Jones C.; Juvonen V.; Johnson K.; Harper P.S.; Shaw D.J.; Housman D.E.;
Cell 68:799-808(1992)
Cited for: NUCLEOTIDE SEQUENCE [MRNA] OF 43-629 (ISOFORM 2); INVOLVEMENT IN DM1; VARIANT VAL-423;

Disclaimer: Any medical or genetic information present in this entry is provided for research, educational and informational purposes only. They are not in any way intended to be used as a substitute for professional medical advice, diagnostic, treatment or care.