Src regulates membrane trafficking of the Kv3.1b channel

•Src inhibits Kv3.1b trafficking to the plasma membrane.•Src induces a dramatic redistribution of Kv3.1b to the endoplasmic reticulum.•Src decreases the peak current densities of the Kv3.1b channel.•Src alters the steady-state inactivation of the kv3.1b channel. The Kv3.1 channel plays a crucial role in regulating the high-frequency firing properties of neurons. Here, we determined whether Src regulates the subcellular distributions of the Kv3.1b channel. Co-expression of active Src induced a dramatic redistribution of Kv3.1b to the endoplasmic reticulum. Furthermore, co-expression of the Kv3.1b channel with active Src induced a remarkable decrease in the pool of Kv3.1b at the cell surface. Moreover, the co-expression of active Src results in a significant decrease in the peak current densities of the Kv3.1b channel, and a substantial alteration in the voltage dependence of its steady-state inactivation. Taken together, these results indicate that Src kinase may play an important role in regulating membrane trafficking of Kv3.1b channels.