FXYD family
Encyclopedia
The FXYD protein family is a family of small membrane proteins that share a 35-amino acid signature sequence domain, beginning with the sequence PFXYD and containing 7 invariant and 6 highly conserved amino acids. The approved human gene nomenclature for the family is FXYD-domain containing ion transport regulator.
It contains at least seven members in mammals. Two other family members that are not obvious orthologs of any identified mammalian FXYD protein exist in zebrafish. All these proteins share a signature sequence of six conserved amino acids comprising the FXYD motif in the NH2-terminus, and two glycines and
one serine residue in the transmembrane domain. FXYD proteins are widely distributed in mammalian tissues with prominent expression in tissues that perform fluid and solute transport or that are electrically excitable.
Initial functional characterization suggested that FXYD proteins act as channels or as modulators of ion channels however studies have revealed that most FXYD proteins have another specific function and act as tissue-specific
regulatory subunits of the Na,K-ATPase. Each of these auxiliary subunits produces a distinct functional effect on the transport characteristics of the Na,K-ATPase that is adjusted to the specific functional demands of the tiss
ue in which the FXYD protein is expressed. FXYD proteins appear to preferentially associate with Na,K-ATPase alpha1-beta isozymes, and affect their function in a way that render them operationally complementary or supplementary to coexisting isozymes.
; FXYD2
; FXYD3
; FXYD4; FXYD5
; FXYD6
; FXYD7; FXYD8;
KCT1;
It contains at least seven members in mammals. Two other family members that are not obvious orthologs of any identified mammalian FXYD protein exist in zebrafish. All these proteins share a signature sequence of six conserved amino acids comprising the FXYD motif in the NH2-terminus, and two glycines and
one serine residue in the transmembrane domain. FXYD proteins are widely distributed in mammalian tissues with prominent expression in tissues that perform fluid and solute transport or that are electrically excitable.
Initial functional characterization suggested that FXYD proteins act as channels or as modulators of ion channels however studies have revealed that most FXYD proteins have another specific function and act as tissue-specific
regulatory subunits of the Na,K-ATPase. Each of these auxiliary subunits produces a distinct functional effect on the transport characteristics of the Na,K-ATPase that is adjusted to the specific functional demands of the tiss
ue in which the FXYD protein is expressed. FXYD proteins appear to preferentially associate with Na,K-ATPase alpha1-beta isozymes, and affect their function in a way that render them operationally complementary or supplementary to coexisting isozymes.
Human proteins containing this domain
FXYD1FXYD1
Phospholemman is a protein that in humans is encoded by the FXYD1 gene.-Further reading:...
; FXYD2
FXYD2
Sodium/potassium-transporting ATPase gamma chain is an enzyme that in humans is encoded by the FXYD2 gene.-Further reading:...
; FXYD3
FXYD3
FXYD domain-containing ion transport regulator 3 is a protein that in humans is encoded by the FXYD3 gene.-Further reading:...
; FXYD4; FXYD5
FXYD5
FXYD domain-containing ion transport regulator 5 is a protein that in humans is encoded by the FXYD5 gene.-Further reading:...
; FXYD6
FXYD6
FXYD6 , or FXYD domain-containing ion transport regulator 6, is a gene which is located at the 11q23.3 . The FXYD6 protein contains 95 amino acids, and can be found in all human tissues except blood....
; FXYD7; FXYD8;
KCT1;