UniProtKB/Swiss-Prot P01034: Variant p.Ala25Thr

Cystatin-C
Gene: CST3
Chromosomal location: 20p11.21
Variant information

Variant position:  25
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 have been found in patients and disease-association is reported in literature. However, this classification is not a definitive assessment of variant pathogenicity.
  • Polymorphism: No disease-association has been reported.
  • Unclassified: Variants have been found in patients but disease-association remains unclear.

Residue change:  From Alanine (A) to Threonine (T) at position 25 (A25T, p.Ala25Thr).
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:  Change from small size and hydrophobic (A) to medium size and polar (T)
The physico-chemical property of the reference and variant residues and the change implicated.

BLOSUM score:  0
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

Variant description:  Associated with ARMD11 and O-glycosylated in region between AA 22-28.
Any additional useful information about the variant.

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



Sequence information

Variant position:  25
The position of the amino-acid change on the UniProtKB canonical protein sequence.

Protein sequence length:  146
The length of the canonical sequence.

Location on the sequence:   LRAPLLLLAILAVALAVSPA  A GSSPGKPPRLVGGPMDASVE
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.

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
Signal peptide 1 – 26
Site 37 – 37 Reactive site
Mutagenesis 25 – 25 A -> S. Shows a dual distribution to the Golgi apparatus and to the mitochondria.


Literature citations

The human cystatin C gene (CST3) is a member of the cystatin gene family which is localized on chromosome 20.
Saitoh E.; Sabatini L.M.; Eddy R.L.; Shows T.B.; Azen E.A.; Isemura S.; Sanada K.;
Biochem. Biophys. Res. Commun. 162:1324-1331(1989)
Cited for: NUCLEOTIDE SEQUENCE [GENOMIC DNA]; VARIANT THR-25;

CST3 genotype associated with exudative age related macular degeneration.
Zurdel J.; Finckh U.; Menzer G.; Nitsch R.M.; Richard G.;
Br. J. Ophthalmol. 86:214-219(2002)
Cited for: ASSOCIATION OF VARIANT THR-25 WITH ARMD11;

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.