UniProtKB/Swiss-Prot Q09470 : Variant p.Asn255Asp
Potassium voltage-gated channel subfamily A member 1
Gene: KCNA1
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Variant information
Variant position:
255
The position of the amino-acid change on the UniProtKB canonical protein sequence.
Type of variant:
LP/P [Disclaimer : Variants classification is intended for research purposes only, not for clinical and diagnostic use . The label disease variant is assigned according to literature reports on probable disease-association that can be based on theoretical reasons. This label must not be considered as a definitive proof for the pathogenic role of a variant. ]
The variants are classified into three categories: LP/P, LB/B and US.LP/P: likely pathogenic or pathogenic. LB/B: likely benign or benign. US: uncertain significance
Residue change:
From Asparagine (N) to Aspartate (D) at position 255 (N255D, p.Asn255Asp).
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 medium size and polar (N) to medium size and acidic (D)
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
Variant description:
In MK1; strongly reduces the activity of homomeric channels with dominant negative effects on wild-type channels.
Any additional useful information about the variant.
Other resources:
Links to websites of interest for the variant.
Sequence information
Variant position:
255
The position of the amino-acid change on the UniProtKB canonical protein sequence.
Protein sequence length:
495
The length of the canonical sequence.
Location on the sequence:
ELVVRFFACPSKTDFFKNIM
N FIDIVAIIPYFITLGTEIAE
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 ELVVRFFACPSKTDFFKNIMN FIDIVAIIPYFITLGTEIAE
Mouse ELVVRFFACPSKTDFFKNIMN FIDIVAIIPYFITLGTEIAE
Rat ELVVRFFACPSKTDFFKNIMN FIDIVAIIPYFITLGTEIAE
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.
Type Positions Description
Chain
1 – 495
Potassium voltage-gated channel subfamily A member 1
Transmembrane
254 – 274
Helical; Name=Segment S3
Lipidation
243 – 243
S-palmitoyl cysteine
Mutagenesis
243 – 243
C -> A. Strongly decreases palmitoylation and alters current kinetics.
Mutagenesis
255 – 255
N -> AHT. Slightly increases channel activity, but does not affect expression at the cell membrane.
Mutagenesis
255 – 255
N -> E. Abolishes channel activity, but does not affect expression at the cell membrane.
Mutagenesis
255 – 255
N -> Q. Strongly reduces channel activity, but does not affect expression at the cell membrane.
Mutagenesis
255 – 255
N -> V. No effect on channel activity.
Literature citations
A missense mutation in the Kv1.1 voltage-gated potassium channel-encoding gene KCNA1 is linked to human autosomal dominant hypomagnesemia.
Glaudemans B.; van der Wijst J.; Scola R.H.; Lorenzoni P.J.; Heister A.; van der Kemp A.W.; Knoers N.V.; Hoenderop J.G.; Bindels R.J.;
J. Clin. Invest. 119:936-942(2009)
Cited for: VARIANT MK1 ASP-255; CHARACTERIZATION OF VARIANT MK1 ASP-255; FUNCTION; TRANSPORTER ACTIVITY; SUBCELLULAR LOCATION; ACTIVITY REGULATION;
Functional analysis of the Kv1.1 N255D mutation associated with autosomal dominant hypomagnesemia.
van der Wijst J.; Glaudemans B.; Venselaar H.; Nair A.V.; Forst A.L.; Hoenderop J.G.; Bindels R.J.;
J. Biol. Chem. 285:171-178(2010)
Cited for: CHARACTERIZATION OF VARIANT MK1 ASP-255; MUTAGENESIS OF ASN-255; FUNCTION; TRANSPORTER ACTIVITY; SUBCELLULAR LOCATION;
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.