Sodium channel neurotoxin MeuNaTxalpha-1

UniProtKB accession:  P86408

Grouped By:  Matching UniProtKB accession

UniProtKB description:  Alpha toxins bind voltage-independently at site-3 of sodium channels (Nav) and inhibit the inactivation of the activated channels, thereby blocking neuronal transmission. This toxin inhibits inactivation of Nav1.6/SCN8A (EC(50)=3.1 uM) and drosophila DmNav1 (EC(50)=1.17 uM) (PubMed:21969612, Ref.2, PubMed:33051988). It also shows a weak inhibition of inactivation on Nav1.2/SCN2A Nav1.3/SCN3A, and Nav1.7/SCN9A (PubMed:21969612, PubMed:33051988). The toxin (1 uM) does not significantly shift the midpoint of activation at the two channels, but induces a significant depolarizing shift in the V(1/2) of inactivation of the channels (PubMed:21969612). The toxin has also been shown to dose-dependently stimulates intracellular signaling in DRG neurons through activation of two kinases (type II protein kinase A (PKA-II) and MAP kinases 1/3 (MAPK1/MAPK3)) (PubMed:33051988). Nav1.2/SCN2A is strongly suggested to be the target channel predominantly involved in this activation (PubMed:33051988). In vivo, the toxin induces a dose-dependent thermal hyperalgesia lasting 30-45 minutes (PubMed:33051988).