Acid-sensing ion channel 3 (ASIC3) also known as amiloride-sensitive cation channel 3 (ACCN3) or testis sodium channel 1 (TNaC1) is a

protein Proteins are large biomolecules and macromolecules that comprise one or more long chains of amino acid residues. Proteins perform a vast array of functions within organisms, including catalysing metabolic reactions, DNA replication, respon ...

that in humans is encoded by the ASIC3

gene In biology, the word gene (from , ; "... Wilhelm Johannsen coined the word gene to describe the Mendelian units of heredity..." meaning ''generation'' or ''birth'' or ''gender'') can have several different meanings. The Mendelian gene is a b ...

. The ASIC3 gene is one of the five

paralogous Sequence homology is the biological homology between DNA, RNA, or protein sequences, defined in terms of shared ancestry in the evolutionary history of life. Two segments of DNA can have shared ancestry because of three phenomena: either a spe ...

genes that encode proteins that form trimeric

acid-sensing ion channel Acid-sensing ion channels (ASICs) are neuronal voltage-insensitive sodium channels activated by extracellular protons permeable to Na+. ASIC1 also shows low Ca2+ permeability. ASIC proteins are a subfamily of the ENaC/Deg superfamily of ion channe ...

s (ASICs) in mammals. The cDNA of this gene was first cloned in 1998. The ASIC genes have splicing variants that encode different proteins that are called isoforms. These genes are mainly expressed in the central and peripheral nervous system. ASICs can form both homotrimeric (meaning composed of three identical subunits) and heterotrimeric channels.

Structure and function

This gene encodes a member of the ASIC/

ENaC The epithelial sodium channel (ENaC), (also known as amiloride-sensitive sodium channel) is a membrane-bound ion channel that is selectively permeable to sodium ions (). It is assembled as a heterotrimer composed of three homologous subunits α ...

superfamily of proteins. The members of this family are

amiloride Amiloride, sold under the trade name Midamor among others, is a medication typically used with other medications to treat high blood pressure or swelling due to heart failure or cirrhosis of the liver. Amiloride is classified as a potassium-spar ...

-sensitive

sodium Sodium is a chemical element with the symbol Na (from Latin ''natrium'') and atomic number 11. It is a soft, silvery-white, highly reactive metal. Sodium is an alkali metal, being in group 1 of the periodic table. Its only stable ...

channels that contain

intracellular This glossary of biology terms is a list of definitions of fundamental terms and concepts used in biology, the study of life and of living organisms. It is intended as introductory material for novices; for more specific and technical definitions ...

N and C termini, 2

hydrophobic In chemistry, hydrophobicity is the physical property of a molecule that is seemingly repelled from a mass of water (known as a hydrophobe). In contrast, hydrophiles are attracted to water. Hydrophobic molecules tend to be nonpolar and, ...

transmembrane A transmembrane protein (TP) is a type of integral membrane protein that spans the entirety of the cell membrane. Many transmembrane proteins function as gateways to permit the transport of specific substances across the membrane. They frequentl ...

(TM) regions, and a large

extracellular This glossary of biology terms is a list of definitions of fundamental terms and concepts used in biology, the study of life and of living organisms. It is intended as introductory material for novices; for more specific and technical definitions ...

loop, which has many

cysteine Cysteine (symbol Cys or C; ) is a semiessential proteinogenic amino acid with the formula . The thiol side chain in cysteine often participates in enzymatic reactions as a nucleophile. When present as a deprotonated catalytic residue, s ...

residues with conserved spacing. The TM regions are generally symbolized as TM1 (clone to N-terminus) and TM2 (close to C-terminus). The pore of the channel through which ions selectively flow from the extracellular side into the cytoplasm is formed by the three TM2 regions of the trimer.

Interactions

ASIC3 has been shown to

interact Advocates for Informed Choice, dba interACT or interACT Advocates for Intersex Youth, is a 501(c)(3) nonprofit organization using innovative strategies to advocate for the legal and human rights of children with intersex traits. The organizat ...

with

LIN7B Lin-7 homolog B is a protein that in humans is encoded by the ''LIN7B'' gene. Interactions LIN7B has been shown to interact with: * ACCN3, * GRIN2B, * KCNJ12 and * KCNJ4 Potassium inwardly-rectifying channel, subfamily J, member 4, also kno ...

, GOPC and

MAGI1 Membrane-associated guanylate kinase, WW and PDZ domain-containing protein 1 is an enzyme that in humans is encoded by the ''MAGI1'' gene. Function The protein encoded by this gene is a member of the membrane-associated guanylate kinase homolog ...

Structure and function

Interactions

References

External links

Further reading