Accn4 | GeneID:63882 | Rattus norvegicus

AJ242554   AJ271642   CB703338   NM_022234  

CAB61836   CAB93984   EDL75443   EDL75444   NP_071570   Q9JHS6  

• Rn.44831 cluster

1. [ ] Andrey F, et al. (2005) "Acid sensing ionic channels: modulation by redox reagents." Biochim Biophys Acta. 1745(1):1-6. PMID:16085050

Acid-sensing ion channels (ASICs) are widely expressed in mammalian sensory neurons and supposedly play a role in nociception and acid sensing. In the course of functioning the redox status of the tissue is subjected to changes. Using whole-cell patch-clamp/concentration clamp techniques we have investigated the effect of redox reagents on the ASIC-like currents in the sensory ganglia and hippocampal neurons of rat. The reducing agent dithiothreitol (DTT), when applied in the concentrations 1-2 mM, reversibly potentiates proton-activated currents, while the oxidizing reagent 5,5'-dithio-bis-(2-nitrobenzoic acid) (DTNB) causes their inhibition. The EC50 and Hill coefficient for the activation of ASIC-like currents by protons are not affected by DTT. Redox modulation of proton-activated currents is independent on the membrane potential and on the level of pH used for the current activation. The endogenous antioxidant tripeptide glutathione (its reduced form, g-l-glutamyl-l-cysteinyl-glycine, GSH) also potentiates proton-activated currents. Our results indicate that ASIC-like currents are susceptible to regulation by redox agents.

2. [ ] Grunder S, et al. (2000) "A new member of acid-sensing ion channels from pituitary gland." Neuroreport. 11(8):1607-1611. PMID:10852210

Acid-sensing ion channels (ASICs) constitute a branch of the super-gene family of amiloride-sensitive sodium channels. So far five different ASICs have been cloned from mammalian tissues. They are activated by a drop of extracellular pH but differ with respect to effective agonist concentration, desensitization and mRNA expression pattern. Here we report cloning of ASIC4, a new protein showing about 45% identity to other ASICs. ASIC4 is 97% identical between rat and human and shows strongest expression in pituitary gland. Moreover, we detected expression throughout the brain, in spinal cord, and inner ear. ASIC4 cannot be activated by a drop of extracellular pH in Xenopus oocytes, suggesting association with other subunits or activation by a ligand different from protons. Our results suggest a role for ASICs also in endocrine glands.

3. [ ] Akopian AN, et al. (2000) "A new member of the acid-sensing ion channel family." Neuroreport. 11(10):2217-2222. PMID:10923674

Acid-sensing ion channels (ASICs) are members of the epithelial sodium channel (ENaC)-degenerin family of two-pass transmembrane segment protein subunits which form multimeric cation channels. Members of the ENaC-degenerin family are gated by stimuli as diverse as protons, peptides and mechanical distension. Here we describe a new member of the family, SPASIC or ASIC 4 (spinal cord ASIC) which is expressed throughout the central nervous system in an overlapping population of neurons that also express the ASIC subunit MDEG2. ASIC-4 which shows 44% identify with ASIC is developmentally regulated and expressed in a subset of sensory neurons as well as in the CNS. However, despite the strong homology with ASIC, the ASIC-4 transcript does not encode a proton gated cation channel.