Kcnk7

Potassium channel subfamily K member 7 (Double-pore K(+) channel 3) (Neuromuscular two p domain potassium channel) (Putative potassium channel DP3)

Spatial tier: REGION_BIASED · Class: ION_CHANNEL · Top region: SCO (Subcommissural organ) · Positive regions: 33/554

44.1Discovery Score

35.0Targetability Score

CEvidence grade C

What this means: Kcnk7: fine CCF profile is region-biased toward SCO (top regions: SCO, PVpo, PVi, LM, AP); this is a discovery lead, not direct proof.

Function in SCO: evidence, prediction, innovation

Gene function

KCNK7 belongs to the two-pore-domain (K2P) potassium channel family, whose members normally produce background leak currents that set resting membrane potential. KCNK7 is atypical: its first pore domain carries a non-canonical selectivity-filter sequence and it has not been made to conduct in heterologous systems, so it is treated as a silent or conditionally active K2P subunit, possibly requiring a partner subunit.

Region function

The subcommissural organ is an ependymal secretory gland in the roof of the third ventricle at the posterior commissure; it secretes SCO-spondin into cerebrospinal fluid to form Reissner's fibre, which contributes to CSF flow, aqueduct patency and axial/neurodevelopmental signalling.

Published in this region

none No region-specific literature found. The closest data are distribution surveys: Medhurst 2001 profiled human two-pore potassium channels across CNS and peripheral tissues, and Salinas 1999 described the family member cloning and the unusual pore structure of this branch; neither addressed the subcommissural organ.

Predicted function

Prediction: in subcommissural organ ependymocytes a K2P background conductance would set the resting potential and the potassium gradient that drives transepithelial ion and water movement into the CSF, coupling membrane potential to SCO-spondin secretion. If KCNK7 is silent alone, it most plausibly acts as a regulatory partner that suppresses or modifies other K2P channels in these cells. Knockdown is predicted to depolarise SCO ependymocytes and change secretory rate and CSF ionic composition, with hydrocephalus-relevant consequences; heterologous reconstitution with candidate partners is the first experiment.

Innovation

★★★★★ 5/5 A functionally orphan potassium channel in a secretory CSF organ is unexplored territory, though its silence in heterologous systems makes it technically risky.

Tools

none known specific to KCNK7 (no selective blocker, no established knockout phenotype); approach via AAV-shRNA/CRISPR knockdown in FoxJ1-CreER mice plus anti-KCNK7 antibodies and heterologous expression assays.

References

Direct evidence located at the region

Kcnk7 Allen ISH at the CCF centroid of SCO

Allen ISH experiment 73496923, section image 72580556 (section 157): the section that contains the CCF centroid of Subcommissural organ according to the Allen image-to-atlas alignment (reference_to_image), with a 2 mm window around that point. Left: whole section, red box = window. Middle: ISH signal. Right: Allen's expression-mask view of the same window. open this image in the Allen viewer

Look it up yourself: Allen Mouse Brain ISH for Kcnk7 Allen reference atlas: SCO (structure 599626923)ABC Atlas MERFISH viewer(in the ABC Atlas choose dataset MERFISH-C57BL6J-638850-CCF, colour cells by gene "Kcnk7" or by parcellation_substructure "SCO")All genes confined to SCO + 3-D brain

Direct spatial evidence

SCO MERFISH region locator — Real single-cell MERFISH coordinates for the SCO (Subcommissural organ) section -- our own ground-truth data, showing exactly where this region sits, independent of whether the Allen ISH section below is easy to read.

Regional expression figure

Predicted WMB × fine-CCF profile; not direct full-transcriptome spatial measurement.

Spatial profile

SCO

0.245

PVpo

0.22

PVi

0.22

0.181

0.173

0.163

0.161

PVp

0.142

SFO

0.139

PVa

0.138

SCzo

0.132

MMd

0.126

RPA

0.124

0.118

SUM

0.11

LRNp

0.109

0.108

PVH

0.107

TMv

0.105

PVT

0.101

Evidence and specificity

Evidence status: PREDICTED_FINE
Direct sources: None; predicted localization only
Exclusive threshold: 12 positive regions out of 554
Spatial specificity: 0.309
Top-region fraction: 0.048
Filter status: PASS

Interpretation limits

Cell-type-to-region projection is imputed expression, not direct spatial measurement.
Adult reference atlases do not establish stability across age, sex, strain, state, or disease.
Transcript abundance does not guarantee protein abundance or genetic-tool performance.