Chloride channels are a superfamily of poorly understood ion channels specific for chloride. These channels may conduct many different ions, but are named for chloride because its concentration in vivo is much higher than other anions. Several families of voltage-gated channels and ligand-gated channels have been characterized in humans.
Kv7.2 (KvLQT2) is a voltage- and lipid-gated potassium channel protein coded for by the gene KCNQ2.
The sulfate transporter is a solute carrier family protein that in humans is encoded by the SLC26A2 gene. SLC26A2 is also called the diastrophic dysplasia sulfate transporter (DTDST), and was first described by Hästbacka et al. in 1994. A defect in sulfate activation described by Superti-Furga in achondrogenesis type 1B was subsequently also found to be caused by genetic variants in the sulfate transporter gene. This sulfate (SO42−) transporter also accepts chloride, hydroxyl ions (OH−), and oxalate as substrates. SLC26A2 is expressed at high levels in developing and mature cartilage, as well as being expressed in lung, placenta, colon, kidney, pancreas and testis.
The CLCN family of voltage-dependent chloride channel genes comprises nine members which demonstrate quite diverse functional characteristics while sharing significant sequence homology. The protein encoded by this gene regulates the electric excitability of the skeletal muscle membrane. Mutations in this gene cause two forms of inherited human muscle disorders: recessive generalized myotonia congenita (Becker) and dominant myotonia (Thomsen).
The CLCN5 gene encodes the chloride channel Cl-/H+ exchanger ClC-5. ClC-5 is mainly expressed in the kidney, in particular in proximal tubules where it participates to the uptake of albumin and low-molecular-weight proteins, which is one of the principal physiological role of proximal tubular cells. Mutations in the CLCN5 gene cause an X-linked recessive nephropathy named Dent disease characterized by excessive urinary loss of low-molecular-weight proteins and of calcium (hypercalciuria), nephrocalcinosis and nephrolithiasis.
protein S6 kinase, 90kDa, polypeptide 3, also s RPS6KA3, is an enzyme that in humans is encoded by the RPS6KA3 gene.
Na(+)/H(+) exchange regulatory cofactor NHE-RF3 is a protein that in humans is encoded by the PDZK1 gene.
Chloride channel accessory 1 is a protein that in humans is encoded by the CLCA1 gene.
Chloride anion exchanger, also known as down-regulated in adenoma, is a protein that in humans is encoded by the SLC26A3 gene.
Chloride intracellular channel 4, also known as CLIC4, is a eukaryotic gene.
H+/Cl− exchange transporter 3 is a protein that in humans is encoded by the CLCN3 gene.
Chloride channel 7 alpha subunit also known as H+/Cl− exchange transporter 7 is a protein that in humans is encoded by the CLCN7 gene. In melanocytic cells this gene is regulated by the Microphthalmia-associated transcription factor.
ATP-sensitive inward rectifier potassium channel 10 is a protein that in humans is encoded by the KCNJ10 gene.
Anion exchange protein 3 is a membrane transport protein that in humans is encoded by the SLC4A3 gene. AE3 is functionally similar to the Band 3 Cl−/HCO3− exchange protein but it is expressed primarily in brain neurons and in the heart. Like AE2 its activity is sensitive to pH. AE3 mutations have been linked to seizures.
Chloride channel accessory 2 is a protein that in humans is encoded by the CLCA2 gene.
H(+)/Cl(-) exchange transporter 4 is a protein that in humans is encoded by the CLCN4 gene.
Chloride transport protein 6 is a protein that in humans is encoded by the CLCN6 gene.
Solute carrier family 12 member 7 is a protein that in humans is encoded by the SLC12A7 gene.
Chloride intracellular channel protein 5 is a protein that in humans is encoded by the CLIC5 gene.
Anoctamin-1 (ANO1) also known as Transmembrane member 16A (TMEM16A) is a protein that, in humans, is encoded by the ANO1 gene. Anoctamin-1 is a voltage-gated calcium-activated anion channel, which acts as a chloride channel and a bicarbonate channel. additionally Anoctamin-1 is apical iodide channel. It is expressed in smooth muscle, epithelial cells, vomeronasal neurons, olfactory sustentacular cells, and is highly expressed in interstitial cells of Cajal (ICC) throughout the gastrointestinal tract.
