A cytosolic residue mediates Mg2+ block and regulates inward current amplitude of a transient receptor potential channel.

ABSTRACT: Members of the transient receptor potential (TRP) cation channel family control a wide variety of cellular functions by regulating calcium influx. In neurons, TRP channels may also modulate cell excitability. TRPC5 is a neuronal TRP channel that plays a role in controlling neurite extension in the hippocampus. Transiently expressed TRPC5 exhibits a doubly rectifying current-voltage relationship characterized by relatively large inward currents and a unique outwardly rectifying current with a "flat" segment between +10 and +40 mV that may be attributable to Mg2+ block. We find that intracellular Mg2+ blocks the outward current through TRPC5 with an IC50 of 457 microM. The block is mediated by a cytosolic aspartate residue, D633, situated between the termination of the sixth transmembrane do

SUBMITTER: Obukhov AG 

PROVIDER: S-EPMC6725964 | biostudies-literature | 2005 Feb

REPOSITORIES: biostudies-literature