Kv4.1 is a voltage-dependent K+ channel that belongs to the Shal channel subfamily and includes two other members: Kv4.2 and Kv4.3.
Kv4.1 possesses the signature structure of the voltage-dependent K+ channels: six membrane-spanning domains with intracellular N and C termini. As with other members of the voltage-gated K+ channel superfamily, the functional channel is a tetramer that can be composed of more than one member of the Shal subfamily, i.e. heterotetramers of Kv4.1 and Kv4.2.
The Kv4 channels are characterized by activation at subthreshold membrane potentials, inactivate rapidly and recover from inactivation quickly compared with other voltage-dependent K+ channels. This type of current is known as transient A-type K+ currents. For example, depolarization-activated K+ currents in rat neostriatal cholinergic interneurons are predominantly of the A-type and attributable to coexpression of Kv4.1 and Kv4.2 subunits. The biophysical properties of the Kv4.1 subunit can be modified by its association with auxiliary b subunits such as KChIP1 that increase Kv4.1 current densities and accelerates both the inactivation and the recovery time.
Kv4.1 is highly expressed in brain but is also expressed in peripheral tissues such as colon, heart and lung.
The pharmacology of Kv4.1 has been less well studied than that of the other Kv4 members. Kv4.1 is sensitive to the classical K+ channel blockers, 4-aminopyridine and tetraethylammonium. Recently HmTx1 a peptide blocker derived from the venom of the African tarantula Heteroscodra maculata has been shown to be a potent inhibitor of Kv4.1.
Alomone Labs is pleased to offer a highly specific antibody directed against an intracellular epitope of human Kv4.1. The Anti-Kv4.1 antibody (#AG1094) can be used for western blot, immunohistochemistry and immunocytochemistry applications. It has been designed to recognize Kv4.1 from rat, human and mouse samples.
