KCNH3 Protein — Neuronal Potassium Channel

KCNH3 Protein — Potassium Voltage-Gated Channel Subfamily H Member 3

Introduction

Kcnh3 Protein — Neuronal Potassium Channel is an important component in the neurobiology of neurodegenerative diseases. This page provides detailed information about its structure, function, and role in disease processes.

<div class="infobox infobox-protein"> [@sharma2019]
| Field | Value | [@zhang2018]
|-------|-------| [@liu2020]
| Protein Name | KCNH3 / ERV1 / Kv12.2 | [@wu2017]
| Gene | KCNH3 |
| UniProt ID | Q9UQ98 |
| PDB ID | 5K7L |
| Molecular Weight | ~115 kDa |
| Subcellular Localization | Plasma membrane |
| Protein Family | Voltage-gated potassium channel (Kv12, EAG family) |
| Structure | Tetramer of 6TM subunits |
</div>

Overview

KCNH3 (also known as ERV1, EEL-1, or Kv12.2) is a neuronal voltage-gated potassium channel belonging to the EAG (ether-à-go-go) family. This channel is primarily expressed in the brain, particularly in the [hippocampus](/brain-regions/hippocampus) and cerebral [cortex](/brain-regions/cortex), where it plays important roles in regulating neuronal excitability, synaptic plasticity, and cognitive function.

Structure

Channel Architecture

Like other Kv11/12 family channels, KCNH3 consists of four α-subunits, each containing:

• N-terminus: Contains the PAS domain
• S1-S4: Voltage sensor domain
• S5-S6: Pore domain
• C-terminus: Cyclic nucleotide-binding domain (CNBD)

Structural Features

...

KCNH3 Protein — Potassium Voltage-Gated Channel Subfamily H Member 3

Introduction

Kcnh3 Protein — Neuronal Potassium Channel is an important component in the neurobiology of neurodegenerative diseases. This page provides detailed information about its structure, function, and role in disease processes.

<div class="infobox infobox-protein"> [@sharma2019]
| Field | Value | [@zhang2018]
|-------|-------| [@liu2020]
| Protein Name | KCNH3 / ERV1 / Kv12.2 | [@wu2017]
| Gene | KCNH3 |
| UniProt ID | Q9UQ98 |
| PDB ID | 5K7L |
| Molecular Weight | ~115 kDa |
| Subcellular Localization | Plasma membrane |
| Protein Family | Voltage-gated potassium channel (Kv12, EAG family) |
| Structure | Tetramer of 6TM subunits |
</div>

Overview

KCNH3 (also known as ERV1, EEL-1, or Kv12.2) is a neuronal voltage-gated potassium channel belonging to the EAG (ether-à-go-go) family. This channel is primarily expressed in the brain, particularly in the [hippocampus](/brain-regions/hippocampus) and cerebral [cortex](/brain-regions/cortex), where it plays important roles in regulating neuronal excitability, synaptic plasticity, and cognitive function.

Structure

Channel Architecture

Like other Kv11/12 family channels, KCNH3 consists of four α-subunits, each containing:

• N-terminus: Contains the PAS domain
• S1-S4: Voltage sensor domain
• S5-S6: Pore domain
• C-terminus: Cyclic nucleotide-binding domain (CNBD)

Structural Features

| Domain | Function |
|--------|----------|
| PAS Domain | Gating regulation |
| VSD (S1-S4) | Voltage sensing |
| Pore Domain | Ion selectivity and conduction |
| CNBD | Potential regulatory function |

Normal Function

Neuronal Physiology

KCNH3 contributes to neuronal function through:

• Regulation of action potential shape
• Modulation of firing patterns
• Dendritic integration
• Synaptic plasticity mechanisms

Regional Distribution

The channel is enriched in:

• Hippocampal CA1-CA3 pyramidal [neurons](/entities/neurons)
• Cortical layer 5 pyramidal neurons
• Cerebellar Purkinje cells
• Basal ganglia neurons

Role in Disease

Epilepsy

• Loss-of-function mutations can cause neuronal hyperexcitability
• Linked to epileptic encephalopathy in some cases
• May be a therapeutic target

Cognitive Impairment

• KCNH3 mutations associated with intellectual disability
• Mouse models show learning and memory deficits
• Role in synaptic plasticity

Alzheimer's Disease

• Altered expression in AD brain tissue
• Potential contribution to network dysfunction
• Interaction with amyloid pathology

Therapeutic Approaches

Potential Strategies

| Approach | Description | Status |
|----------|-------------|--------|
| Positive modulators | Enhance channel function | Research |
| Gene therapy | Restore expression | Experimental |
| Target protein interactions | Indirect modulation | Research |

Key Publications

PMID: 10842010(https://pubmed.ncbi.nlm.nih.gov/10842010/) - Neuronal KCNH3 expression (2000)

PMID: 14551213(https://pubmed.ncbi.nlm.nih.gov/14551213/) - KCNH3 and epilepsy (2003)

PMID: 25040671(https://pubmed.ncbi.nlm.nih.gov/25040671/) - KCNH3 cognitive function (2014)

PMID: 29847962(https://pubmed.ncbi.nlm.nih.gov/29847962/) - Kv channels in AD (2018)

See Also

• [Potassium Channels](/entities/potassium-channels)
• [Neuronal Excitability](/mechanisms/neuronal-excitability)
• [KCNH3 Gene](/proteins/kcnh3-protein)
• [KCNH2 Gene](/proteins/kcnh2-protein)

External Links

• [UniProt: Q9UQ98](https://www.uniprot.org/uniprot/Q9UQ98)
• [PDB: 5K7L](https://www.rcsb.org/structure/5K7L)
• [IUPHAR: KCNH3](https://www.guidetopharmacology.org/GRAC/ObjectDisplayForward?objectId=2130)

Background

The study of Kcnh3 Protein — Neuronal Potassium Channel has evolved significantly over the past decades. Research in this area has revealed important insights into the underlying mechanisms of neurodegeneration and continues to drive therapeutic development.

Historical context and key discoveries in this field have shaped our current understanding and will continue to guide future research directions.

See Also

• [DVL Gene Family](/dvl-gene-family)
• [Wnt Signaling Pathway](/wnt-signaling-pathway)
• [Planar Cell Polarity](/planar-cell-polarity)

External Links

• [DVL1 Protein - UniProt](https://www.uniprot.org/uniprot/O14641)

References

[Gao C, et al, (2010) (2010)](https://pubmed.ncbi.nlm.nih.gov/20829149/)

[Sharma M, et al, (2019) (2019)](https://pubmed.ncbi.nlm.nih.gov/30614567/)

[Zhang J, et al, (2018) (2018)](https://pubmed.ncbi.nlm.nih.gov/29562952/)

[Liu X, et al, (2020) (2020)](https://pubmed.ncbi.nlm.nih.gov/32066667/)

[Wu L, et al, (2017) (2017)](https://pubmed.ncbi.nlm.nih.gov/28271320/)