KCNIP1

KCNIP1, also known as calsonin or DREAM (Downstream Regulatory Element Antagonist Modulator), is a member of the KCNIP (K⁺ channel interacting protein) family of proteins. These proteins are small, neuron-specific, calcium-binding proteins that modulate the activity of A-type potassium channels (Kv4 channels).

KCNIP1 acts as an auxiliary subunit for Kv4 channels, influencing their trafficking, gating kinetics, and voltage-dependent inactivation. It can both increase and decrease the surface expression of Kv4 channels depending on the specific isoforms of KCNIP1 and Kv4 channels involved.

Beyond its interaction with Kv4 channels, KCNIP1 also functions as a transcriptional repressor. It binds to specific DNA sequences called downstream regulatory elements (DREs), suppressing the expression of target genes. This transcriptional repression activity is regulated by calcium levels; calcium binding to KCNIP1 can relieve its repression activity.

KCNIP1 is primarily expressed in the brain, particularly in the hippocampus, cerebellum, and cerebral cortex. It plays a role in neuronal excitability, synaptic plasticity, and learning and memory processes. Dysregulation of KCNIP1 has been implicated in various neurological disorders, including epilepsy, Alzheimer's disease, and schizophrenia.