WNK4

Summary

WNK4 (WNK lysine deficient protein kinase 4, HGNC:14544) is a protein-coding gene on chromosome 17q21.2, encoding Serine/threonine-protein kinase WNK4 (Q96J92). Serine/threonine-protein kinase component of the WNK4-SPAK/OSR1 kinase cascade, which acts as a key regulator of ion transport in the distal nephron and blood pressure.

This gene encodes a member of the WNK family of serine-threonine protein kinases. The kinase is part of the tight junction complex in kidney cells, and regulates the balance between NaCl reabsorption and K(+) secretion. The kinase regulates the activities of several types of ion channels, cotransporters, and exchangers involved in electrolyte flux in epithelial cells. Mutations in this gene result in pseudohypoaldosteronism type IIB.

Source: NCBI Gene 65266 — RefSeq curated summary.

At a glance

• Gene–disease (curated): pseudohypoaldosteronism type 2B (Strong, GenCC)
• Clinical variants (ClinVar): 615 total — 3 pathogenic, 3 likely-pathogenic
• Phenotypes (HPO): 6
• Druggable target: yes
• MANE Select transcript: NM_032387

Identifiers

Gene identifiers

Field	Value
HGNC ID	HGNC:14544
Approved symbol	WNK4
Name	WNK lysine deficient protein kinase 4
Location	17q21.2
Locus type	gene with protein product
Status	Approved
Ensembl gene	ENSG00000126562
Ensembl biotype	protein_coding
OMIM	601844
Entrez	65266

Gene structure

Transcript identifiers

Ensembl transcripts: 11 — 7 protein_coding, 2 retained_intron, 1 protein_coding_CDS_not_defined, 1 nonsense_mediated_decay

ENST00000246914, ENST00000587705, ENST00000587745, ENST00000591448, ENST00000592072, ENST00000592669, ENST00000871309, ENST00000871310, ENST00000871311, ENST00000871312, ENST00000871313

RefSeq mRNA: 2 — MANE Select: NM_032387 NM_001321299, NM_032387

CCDS: CCDS11439

Canonical transcript exons

ENST00000246914 — 19 exons

Exon	Start	End
ENSE00000865417	42782758	42782930
ENSE00000947955	42783937	42784157
ENSE00000947956	42784422	42784579
ENSE00000947957	42785097	42785185
ENSE00002776265	42780610	42781316
ENSE00003463662	42787278	42787542
ENSE00003467530	42788130	42788188
ENSE00003469398	42787778	42787899
ENSE00003517530	42794614	42794668
ENSE00003524322	42796481	42796578
ENSE00003555328	42794772	42795382
ENSE00003565620	42795625	42796033
ENSE00003585919	42788681	42788797
ENSE00003587500	42785266	42785482
ENSE00003590278	42796123	42796322
ENSE00003614473	42795461	42795521
ENSE00003660006	42793592	42793729
ENSE00003664205	42788290	42788407
ENSE00003667631	42796686	42797066

Expression profiles

Bgee: expression breadth ubiquitous, 177 present calls, max score 97.37.

FANTOM5 (CAGE): breadth broad, TPM avg 6.0075 / max 182.5074, expressed in 702 samples.

FANTOM5 promoters (1 alternative TSS)

Promoter ID	TPM avg	Samples expressed
160994	6.0075	702

Top tissues by expression

255 total, by Bgee expression score (0-100, higher = more expressed):

Tissue	Anatomy ID	Expression score	Quality
kidney epithelium	UBERON:0004819	97.37	gold quality
renal medulla	UBERON:0000362	91.87	gold quality
lower esophagus mucosa	UBERON:0035834	91.42	gold quality
mucosa of transverse colon	UBERON:0004991	88.19	gold quality
ileal mucosa	UBERON:0000331	87.35	gold quality
adult mammalian kidney	UBERON:0000082	87.27	gold quality
metanephros cortex	UBERON:0010533	87.24	gold quality
rectum	UBERON:0001052	85.33	gold quality
kidney	UBERON:0002113	84.57	gold quality
pancreatic ductal cell	CL:0002079	84.08	silver quality
mucosa of sigmoid colon	UBERON:0004993	83.95	gold quality
colonic mucosa	UBERON:0000317	82.84	gold quality
transverse colon	UBERON:0001157	82.49	gold quality
cortex of kidney	UBERON:0001225	82.36	gold quality
esophagus squamous epithelium	UBERON:0006920	82.11	gold quality
tibia	UBERON:0000979	81.38	gold quality
male germ line stem cell (sensu Vertebrata) in testis	CL:0000089 ∩ UBERON:0000473	80.15	gold quality
stromal cell of endometrium	CL:0002255	79.90	gold quality
prostate gland	UBERON:0002367	79.51	gold quality
metanephros	UBERON:0000081	78.59	gold quality
esophagus mucosa	UBERON:0002469	77.73	gold quality
small intestine Peyer’s patch	UBERON:0003454	74.83	gold quality
esophagus	UBERON:0001043	73.75	gold quality
large intestine	UBERON:0000059	72.91	gold quality
right ovary	UBERON:0002118	72.89	gold quality
colon	UBERON:0001155	72.62	gold quality
intestine	UBERON:0000160	72.53	gold quality
body of stomach	UBERON:0001161	72.46	gold quality
small intestine	UBERON:0002108	72.45	gold quality
left ovary	UBERON:0002119	71.82	gold quality

Single-cell (SCXA)

Detected in 4 experiment(s), a significant marker in 2.

Experiment	Marker?	Max mean expression
E-CURD-119	yes	48.49
E-ANND-3	yes	3.20
E-CURD-135	no	661.23
E-MTAB-6142	no	73.66

Regulation

Is transcription factor: no

Upstream regulators (CollecTRI, top): AP1, ESR1, GATA1, JUN

miRNA regulators (miRDB)

49 targeting WNK4, top 30 by miRDB confidence (max_score; target_count = how many genes the miRNA targets in total — lower means more specific):

miRNA	Max score	Avg score	miRNA target_count
HSA-MIR-6870-5P	99.99	68.55	2115
HSA-MIR-4723-5P	99.97	68.70	2034
HSA-MIR-5698	99.97	68.49	2029
HSA-MIR-7111-5P	99.97	68.48	2062
HSA-MIR-153-5P	99.89	73.86	6317
HSA-MIR-12119	99.87	68.35	1653
HSA-MIR-4447	99.85	67.81	2900
HSA-MIR-6756-5P	99.82	67.97	2466
HSA-MIR-6766-5P	99.68	67.70	2325
HSA-MIR-7157-5P	99.66	69.33	1829
HSA-MIR-3175	99.65	66.30	2031
HSA-MIR-4310	99.59	68.84	2527
HSA-MIR-4328	99.57	71.06	4094
HSA-MIR-4472	99.56	66.08	1478
HSA-MIR-143-3P	99.49	69.05	1457
HSA-MIR-4770	99.49	69.09	1451
HSA-MIR-1207-5P	99.49	69.11	2983
HSA-MIR-140-5P	99.44	67.20	792
HSA-MIR-4460	99.37	68.52	615
HSA-MIR-6088	99.29	68.45	1284
HSA-MIR-4763-3P	99.10	67.83	2649
HSA-MIR-10B-3P	99.04	66.98	988
HSA-MIR-3127-3P	98.94	67.34	1055
HSA-MIR-6756-3P	98.94	66.79	1104
HSA-MIR-4711-5P	98.89	68.00	965
HSA-MIR-942-3P	98.81	69.04	876
HSA-MIR-760	98.81	66.65	1392
HSA-MIR-502-5P	98.77	66.51	906
HSA-MIR-1178-3P	98.57	67.09	890
HSA-MIR-6837-3P	98.42	66.71	1149

Literature-anchored findings (GeneRIF, showing 40)

• Single-nucleotide polymorphims of WNK4 in whites and African Americans with hypertension. (PMID:12719438)
• general role for WNK4 in the regulation of electrolyte flux in diverse epithelia (PMID:14769928)
• The WNK4 mutant possesses a gain-of-function activity and that the claudins may be important molecular targets of WNK4 kinase. (PMID:15070779)
• Mutations in the WNK4 gene identified in Japanese hypertensives may contribute to hypertension and progression of hypertensive complications to some extent. (PMID:15110905)
• In familial hyperkalemia and hypertension with WNK4 mutations, all affected subjects will apparently develop hypertension. Hypercalciuria accompanies hyperkalemia, and both precede hypertension. WNK4 may interact with a calcium channel or transporter. (PMID:15292344)
• data indicate that transient receptor potential channel 4(TRPV4) is functionally regulated by WNK family kinases 1 and 4 at the level of cell surface expression (PMID:16403833)
• data suggest that WNK4 wild type significantly inhibits sodium chloride cotransporter (NCC) surface expression, not owing to an increase in clathrin-mediated endocytosis of NCC, but likely from enhanced degradation of NCC through a lysosomal pathway (PMID:16688122)
• WNK1 and WNK4 gene products and their regulatory effects suggest an essential role for WNKs in coordinating renal Na-Cl reabsorption and K(+) secretion. (PMID:16820787)
• WNK4 positively regulates TRPV5-mediated Ca transport & inhibitory effect of thiazide-sensitive Na+Cl- cotransporter on this process may be involved in pathogenesis of hypercalciuria of familial hyperkalemic hypertension caused by gene mutation in WNK4. (PMID:17018846)
• an SGK1 site in WNK4 regulates Na+ channel and K+ channel activity (PMID:17360471)
• WNK4 regulates transport proteins in different directions and cellular mechanisms. Familial hyperkalemic hypertension-causing mutants of WNK4 exhibit differences regulating ion transport proteins. (PMID:17634397)
• Data demonstrate that WNK4 is a new glucocorticoid-regulated gene whose expression is inhibited through the interaction of glucocorticoid receptor with negative glucocorticoid response elements in the promoter region. (PMID:18096992)
• WNK4-induced MAP kinase stimulation caused by hypertonicity (PMID:18312414)
• This study was aimed at the mechanism underlying the difference in the effects of WNK4 on TRPV5 and TRPV6 through analyzing the difference in TRPV5 and TRPV6 expression in the plasma membrane. (PMID:18703016)
• These results confirm the important role of the acidic motif of WNK4 in its protein-protein interaction with the ROMK channel. (PMID:18755144)
• using real-time PCR and Western blot assays, we show that trichostatin A (TSA), a histone deacetylase inhibitor, upregulated hWNK4 mRNA and protein expression in human embryo kidney 293 cells. (PMID:18793746)
• identified P561L WNK4 mutation which has not been described previously is the probable cause of pseudohypoaldosteronism type II (PMID:19016006)
• The WNK4 gene probably plays an important role in the pathogenesis of essential hypertension. As a missense mutation, the Ala589Ser polymorphism may bring changes to the enzyme’s function(s), resulting in increased susceptibility to the disease. (PMID:19340547)
• WNK4 suppresses plasma membrane expression of the thiazide-sensitive NaCl cotransporter (NCC), diverting it from the trans-Golgi network to the lysosome via an intracellular route. (PMID:19401467)
• c-Src inhibits SGK1-mediated phosphorylation hereby restoring the WNK4-mediated inhibition of ROMK channels thus suppressing K secretion. (PMID:19706464)
• WNK4 promotes sodium chloride co-transporter targeting to the lysosome for degradation via a mechanism involving sortilin. (PMID:19875813)
• The Exon 8 G1155942T polymorphism in WNK4 gene was associated with hypertension in the Kazakhs ethnic group in Xinjiang, and the T allele might be the risk factor for essential hypertension. (PMID:20513278)
• Data find that expression of the N termini of all four WNKs results in modest to strong activation of SGK1. (PMID:20525693)
• The data demonstrate the hWNK4 3’-UTR plays an enhancer role by crosstalking with the promoter, and miR-296 suppresses hWNK4 expression through targeting on its 3’-UTR in a cell-specific fashion. (PMID:20561597)
• Exon 7 C1155547T polymorphism in WNK4 gene is associated with essential hypertension. (PMID:20931534)
• Data show that 17beta-estradiol/ERalpha regulates human WNK4 expression partly through AP-1 binding to the WNK4 promoter. (PMID:20943203)
• WNK4 kinase negatively regulates the anterograde trafficking of MR through kinase-independent mechanism. (PMID:21118716)
• WNK4 and NHERF2 synergistically regulate TRPV5 by enhancing its forward trafficking and increasing its stability at plasma membrane, respectively. (PMID:21187068)
• Data show that K1169E lost its inhibitory effect on NCC surface expression compared to wild-type WNK4 when expressed in HEK293 cells, while it did not change NCC total protein expression. (PMID:21196779)
• WNK4 polymorphism rs56116165 is a rare allelic variant that may contribute to a genetic predisposition to osteoporosis (PMID:21236712)
• WNK4 WT inhibits Maxi K activity by reducing Maxi K protein at the membrane, but the inhibition is not due to an increase in clathrin-mediated endocytosis of Maxi K, but likely due to enhancing its lysosomal degradation. (PMID:21613417)
• hypertension associated polymorphisms in WNK1 and WNK4 may not be predictors for antihypertensive response to diuretics. (PMID:21704025)
• Results show that Tyr512 phosphorylation is a novel signal regulating the prevalence of CFTR at the cell surface and that WNK4 and Syk perform an antagonistic role in this process. (PMID:21807898)
• R1185C mutation disrupts a CaM binding site at the WNK4 COOH-terminal region and alters the phosphorylation of WNK4 by SGK1. (PMID:23054253)
• The CUL3-KLHL3 E3 ligase complex mutated in Gordon’s hypertension syndrome interacts with and ubiquitylates WNK isoforms: disease-causing mutations in KLHL3 and WNK4 disrupt interaction. (PMID:23387299)
• WNK4 inhibits ENaC channel activity independently of Nedd4-2-mediated ENaC ubiquitination. (PMID:23594824)
• KLHL3 is a substrate adaptor for WNK4 in a ubiquitin E3 ligase complex (PMID:23665031)
• WNK4 inhibits Large-conductance, Ca(2 )-activated K( ) channel activity, in part, by increasing channel degradation through an ubiquitin-dependent pathway. (PMID:23885063)
• analysis of how mutations of KLHL3 show less ability to ubiquitinate WNK4 because of KLHL3’s low stability and/or decreased binding to CUL3 or WNK4 (PMID:23962426)
• WNK4 inhibits SNARE formation of syntaxin 13 with VAMP2. (PMID:23993962)

Cross-species orthologs

7 orthologs

Organism	Symbol	Gene ID
danio_rerio	wnk4b	ENSDARG00000088967
mus_musculus	Wnk4	ENSMUSG00000035112
rattus_norvegicus	Wnk4	ENSRNOG00000020441
drosophila_melanogaster	Madm	FBGN0027497
drosophila_melanogaster	Wnk	FBGN0037098
caenorhabditis_elegans		WBGENE00006941
caenorhabditis_elegans	hpo-11	WBGENE00010427

Paralogs (6): WNK1 (ENSG00000060237), NRBP1 (ENSG00000115216), DSTYK (ENSG00000133059), WNK2 (ENSG00000165238), NRBP2 (ENSG00000185189), WNK3 (ENSG00000196632)

Protein

Protein identifiers

Serine/threonine-protein kinase WNK4 — Q96J92 (reviewed: Q96J92)

Alternative names: Protein kinase lysine-deficient 4, Protein kinase with no lysine 4

All UniProt accessions (3): Q96J92, K7ENT7, K7EPB3

UniProt curated annotations — full annotation on UniProt →

Function. Serine/threonine-protein kinase component of the WNK4-SPAK/OSR1 kinase cascade, which acts as a key regulator of ion transport in the distal nephron and blood pressure. The WNK4-SPAK/OSR1 kinase cascade is composed of WNK4, which mediates phosphorylation and activation of downstream kinases OXSR1/OSR1 and STK39/SPAK. Following activation, OXSR1/OSR1 and STK39/SPAK catalyze phosphorylation of ion cotransporters, such as SLC12A1/NKCC2, SLC12A2/NKCC1, SLC12A3/NCC, SLC12A5/KCC2 or SLC12A6/KCC3, regulating their activity. Acts as a molecular switch that regulates the balance between renal salt reabsorption and K(+) secretion by modulating the activities of renal transporters and channels, including the Na-Cl cotransporter SLC12A3/NCC and the K(+) channel, KCNJ1/ROMK. Regulates NaCl reabsorption in the distal nephron by activating the thiazide-sensitive Na-Cl cotransporter SLC12A3/NCC in distal convoluted tubule cells of kidney: activates SLC12A3/NCC in a OXSR1/OSR1- and STK39/SPAK-dependent process. Also acts as a scaffold protein independently of its protein kinase activity: negatively regulates cell membrane localization of various transporters and channels (CFTR, KCNJ1/ROMK, SLC4A4, SLC26A9 and TRPV4) by clathrin-dependent endocytosis. Also inhibits the activity of the epithelial Na(+) channel (ENaC) SCNN1A, SCNN1B, SCNN1D in a inase-independent mechanism. May also phosphorylate NEDD4L.

Subunit / interactions. Interacts with the C-terminal region of KCNJ1.

Subcellular location. Cell junction. Tight junction.

Tissue specificity. Expressed in kidney, colon and skin.

Post-translational modifications. Autophosphorylated at Ser-331 and Ser-335, promoting its activation. Phosphorylated by WNK1 and WNK3. Phosphorylated at Ser-575 in a MAP3K15/ASK3-dependent process in response to osmotic stress or hypotonic low-chloride stimulation. Ubiquitinated by the BCR(KLHL3) complex, leading to its degradation. Also ubiquitinated by the BCR(KLHL2) complex.

Disease relevance. Pseudohypoaldosteronism 2B (PHA2B) [MIM:614491] An autosomal dominant disorder characterized by hypertension, hyperkalemia, hyperchloremia, mild hyperchloremic metabolic acidosis, and correction of physiologic abnormalities by thiazide diuretics. The disease is caused by variants affecting the gene represented in this entry.

Activity regulation. Activation requires autophosphorylation of Ser-331 and Ser-335. Autophosphorylation and subsequent activation is inhibited by increases in intracellular ionic strength: Cl(-) potently inhibits WNK4 kinase activity via direct binding. Also inhibited by K(+) ions.

Domain organisation. The RFXV motif mediates recognition with downstream kinases OXSR1/OSR1 and STK39/SPAK.

Miscellaneous. Incomplete sequence.

Similarity. Belongs to the protein kinase superfamily. Ser/Thr protein kinase family. WNK subfamily.

Isoforms (3)

UniProt ID	Names	Canonical?
Q96J92-1	1	yes
Q96J92-2	2
Q96J92-3	3

RefSeq proteins (2): NP_001308228, NP_115763* (*=MANE)

Domains & families (InterPro)

ID	Name	Type
IPR000719	Prot_kinase_dom	Domain
IPR008271	Ser/Thr_kinase_AS	Active_site
IPR011009	Kinase-like_dom_sf	Homologous_superfamily
IPR024678	Kinase_OSR1/WNK_CCT	Domain
IPR050588	WNK_Ser-Thr_kinase	Family
IPR056865	CCTL2_WNK	Domain

Pfam: PF00069, PF12202, PF24889

Catalyzed reactions (Rhea), 2 shown:

• L-seryl-[protein] + ATP = O-phospho-L-seryl-[protein] + ADP + H(+) (RHEA:17989)
• L-threonyl-[protein] + ATP = O-phospho-L-threonyl-[protein] + ADP + H(+) (RHEA:46608)

UniProt features (75 total): compositionally biased region 17, cross-link 14, sequence variant 11, region of interest 7, modified residue 6, splice variant 6, mutagenesis site 5, binding site 3, chain 1, domain 1, active site 1, sequence conflict 1, helix 1, short sequence motif 1

Structure

Experimental structures (PDB)

3 structures.

PDB	Method	Resolution (Å)
4CHB	X-RAY DIFFRACTION	1.56
2V3S	X-RAY DIFFRACTION	1.7
4CH9	X-RAY DIFFRACTION	1.84

Predicted structure (AlphaFold)

Model	pLDDT	Fraction very-high
AF-Q96J92-F1	58.38	0.20

Functional residue map

Curated UniProt residues grouped by drug-discovery relevance — catalytic, ligand-binding, modification, and mutation-validated positions. Source: UniProtKB sequence features.

Catalytic / active sites (1): 321 (proton acceptor)

Ligand- & substrate-binding residues (3): 184; 254–257; 304

Post-translational modifications (20): 97, 331, 335, 575, 1035, 1217, 157, 175, 186, 226, 241, 328, 387, 393, 450, 454, 1010, 1144, 1157, 1158

Mutagenesis-validated functional residues (5):

Position	Phenotype
575	abolished map3k15/ask3-dependent phosphorylation.
575	mimics phosphorylation without affecting wnk4 kinase activity.
1016	abolished interaction with oxsr1/osr1.
1017	abolished interaction with oxsr1/osr1.
1019	abolished interaction with oxsr1/osr1.

Function

Pathways and Gene Ontology

Reactome pathways

1 pathways

ID	Pathway
R-HSA-2672351	Stimuli-sensing channels

MSigDB gene sets: 227 (showing top): GOBP_POTASSIUM_ION_TRANSPORT, GOBP_MORPHOGENESIS_OF_AN_EPITHELIUM, GOBP_DIGESTION, AAGCAAT_MIR137, GOBP_EPITHELIUM_DEVELOPMENT, GOBP_REGULATION_OF_BLOOD_PRESSURE, GOBP_NEGATIVE_REGULATION_OF_SODIUM_ION_TRANSPORT, GOBP_CIRCULATORY_SYSTEM_PROCESS, GOBP_INFLAMMATORY_RESPONSE, GOBP_SODIUM_ION_TRANSMEMBRANE_TRANSPORT, GOBP_RESPONSE_TO_DIETARY_EXCESS, GOBP_REGULATION_OF_HORMONE_LEVELS, GOBP_HORMONE_TRANSPORT, GOBP_INORGANIC_ANION_TRANSPORT, RACCACAR_AML_Q6

GO Biological Process (27): response to dietary excess (GO:0002021), renal sodium ion transport (GO:0003096), protein phosphorylation (GO:0006468), chloride transport (GO:0006821), inflammatory response (GO:0006954), signal transduction (GO:0007165), intracellular protein localization (GO:0008104), regulation of blood pressure (GO:0008217), gene expression (GO:0010467), negative regulation of sodium ion transport (GO:0010766), intracellular chloride ion homeostasis (GO:0030644), intracellular signal transduction (GO:0035556), sodium ion transmembrane transport (GO:0035725), aldosterone secretion (GO:0035932), macrophage activation (GO:0042116), monoatomic ion homeostasis (GO:0050801), calcium ion homeostasis (GO:0055074), renal sodium ion absorption (GO:0070294), ERK1 and ERK2 cascade (GO:0070371), cellular response to xenobiotic stimulus (GO:0071466), potassium ion transmembrane transport (GO:0071805), distal tubule morphogenesis (GO:0072156), negative regulation of pancreatic juice secretion (GO:0090188), negative regulation of protein localization to plasma membrane (GO:1903077), regulation of potassium ion export across plasma membrane (GO:1903764), response to xenobiotic stimulus (GO:0009410), homeostatic process (GO:0042592)

GO Molecular Function (10): protein kinase activity (GO:0004672), protein serine/threonine kinase activity (GO:0004674), ATP binding (GO:0005524), ion channel inhibitor activity (GO:0008200), chloride ion binding (GO:0031404), protein serine kinase activity (GO:0106310), nucleotide binding (GO:0000166), protein binding (GO:0005515), kinase activity (GO:0016301), transferase activity (GO:0016740)

GO Cellular Component (7): cytoplasm (GO:0005737), cytosol (GO:0005829), bicellular tight junction (GO:0005923), membrane (GO:0016020), protein-containing complex (GO:0032991), cell body (GO:0044297), anchoring junction (GO:0070161)

Reactome top-level categories

Rollup of top-1 pathways:

Category	Pathways
Ion channel transport	1

GO top-level categories

Rollup of top GO terms by namespace:

Category	Terms
cellular anatomical structure	4
sodium ion transport	3
intracellular anatomical structure	2
protein kinase activity	2
response to nutrient levels	1
energy homeostasis	1
renal system process	1
phosphorylation	1
protein modification process	1
monoatomic anion transport	1
inorganic anion transport	1
defense response	1
cell communication	1
cellular process	1
signaling	1
regulation of cellular process	1
cellular response to stimulus	1
macromolecule localization	1
blood circulation	1
regulation of biological quality	1
macromolecule biosynthetic process	1
regulation of sodium ion transport	1
negative regulation of monoatomic ion transport	1
intracellular monoatomic anion homeostasis	1
chloride ion homeostasis	1
signal transduction	1
monoatomic cation transmembrane transport	1
organic hydroxy compound transport	1
mineralocorticoid secretion	1
myeloid leukocyte activation	1
chemical homeostasis	1
monoatomic cation homeostasis	1
inorganic ion homeostasis	1
renal sodium ion transport	1
renal absorption	1
MAPK cascade	1
response to xenobiotic stimulus	1
cellular response to chemical stimulus	1
kinase activity	1
phosphotransferase activity, alcohol group as acceptor	1

Protein interactions and networks

STRING

801 interactions, top by confidence (×1000):

Protein A	Protein B	Partner UniProt	Score
WNK4	KCNJ1	P48048	967
WNK4	SLC12A3	P55017	966
WNK4	KLHL3	Q9UH77	913
WNK4	SLC12A1	Q13621	903
WNK4	SLC12A2	P55011	871
WNK4	ITSN1	Q15811	827
WNK4	SLC12A4	Q9UP95	780
WNK4	SLC12A5	Q9H2X9	778
WNK4	SCNN1B	P51168	751
WNK4	SCNN1A	P37088	745
WNK4	SCNN1G	P51170	728
WNK4	CUL3	Q13618	720
WNK4	NEDD4L	Q96PU5	705
WNK4	KLHL2	O95198	702
WNK4	ITSN2	Q9NZM3	697

IntAct

25 interactions, top by confidence:

A	B	Type	Score
SMARCD1	ARID1A	psi-mi:“MI:0914”(association)	0.790
OXSR1	WNK4	psi-mi:“MI:0407”(direct interaction)	0.680
WNK4	OXSR1	psi-mi:“MI:0407”(direct interaction)	0.680
YWHAZ	HSPB1	psi-mi:“MI:0914”(association)	0.680
BCL6	HDAC4	psi-mi:“MI:0914”(association)	0.500
ESR2	FBLL1	psi-mi:“MI:0914”(association)	0.460
WNK4	YWHAE	psi-mi:“MI:0915”(physical association)	0.400
SFN	WNK4	psi-mi:“MI:0915”(physical association)	0.400
WNK4	GDF5	psi-mi:“MI:0915”(physical association)	0.400
WNK4	HSP90AB1	psi-mi:“MI:0915”(physical association)	0.400
WNK4	KLHL3	psi-mi:“MI:0915”(physical association)	0.400
HMGB1	WNK4	psi-mi:“MI:0915”(physical association)	0.370
BCL6	CACNA1A	psi-mi:“MI:0914”(association)	0.350

BioGRID (40): WNK4 (Reconstituted Complex), WNK4 (Affinity Capture-Western), WNK4 (Biochemical Activity), KLHL3 (Affinity Capture-Western), WNK4 (Affinity Capture-Western), KLHL3 (Reconstituted Complex), WNK4 (Two-hybrid), WNK4 (Two-hybrid), COPS5 (Affinity Capture-Western), CUL3 (Affinity Capture-Western), WNK4 (Protein-peptide), RMND5A (Affinity Capture-Western), MAEA (Affinity Capture-Western), WNK1 (Affinity Capture-Western), WNK4 (Negative Genetic)

ESM2 similar proteins: A1YEW3, A1YG31, A2T715, A2T7M0, A6NEV1, A6NGD5, A6NJL1, A6QPT6, A8MXV6, A8MZF0, A8WFF7, O08664, P03327, P06936, P0C6A0, P0DPQ3, P54257, P57086, P86478, P86479, P86480, P86481, P86496, Q13487, Q32PG5, Q505G4, Q5R7P6, Q68FX5, Q6J1H4, Q6NZN1, Q6ZMS7, Q6ZRT6, Q76NI1, Q7L3V2, Q7TPK6, Q7YR42, Q7Z6I6, Q80UE6, Q8IY33, Q8K2W9

Diamond homologs: A0A509AKL0, A1Z9X0, A2CI34, A2CI35, A5K0N4, O73792, P00537, P00538, P00540, P04409, P05128, P05129, P05696, P06245, P09215, P0CD62, P10102, P16879, P17252, P20444, P28582, P28867, P32593, P43298, P63318, P63319, P83099, P83741, P93050, P93759, Q02111, Q04759, Q05655, Q12469, Q1L6Q1, Q20CR4, Q2MHE4, Q38868, Q38872, Q38873

SIGNOR signaling

16 interactions.

A	Effect	B	Mechanism
KLHL3	“down-regulates quantity by destabilization”	WNK4	binding
“Cullin 3-RBX1-Skp1”	“down-regulates quantity by destabilization”	WNK4	polyubiquitination
KLHL2	“down-regulates quantity by destabilization”	WNK4	binding
SRC	“down-regulates activity”	WNK4	phosphorylation
WNK4	“up-regulates activity”	OXSR1	phosphorylation
SGK1	“down-regulates activity”	WNK4	phosphorylation
WNK4	“up-regulates activity”	SLC12A3	phosphorylation
WNK4	“down-regulates activity”	SLC12A3
WNK4	“up-regulates activity”	STK39	phosphorylation
SGK1	“up-regulates activity”	WNK4	phosphorylation
WNK4	“down-regulates activity”	WNK4	phosphorylation

Disease & clinical

Clinical variants and AI predictions

ClinVar

615 variants total. Per-class counts are floors (≥ shown; pagination cap):

Classification	Count (floor)
Pathogenic	3
Likely pathogenic	3
Uncertain significance	379
Likely benign	86
Benign	57

Top pathogenic / likely-pathogenic (6)

Variant ID	HGVS	Classification
1344664	NM_032387.5(WNK4):c.506C>T (p.Pro169Leu)	Pathogenic
7660	NM_032387.5(WNK4):c.1693C>G (p.Gln565Glu)	Pathogenic
7662	NM_032387.5(WNK4):c.1691A>C (p.Asp564Ala)	Pathogenic
1177431	NM_032387.5(WNK4):c.3108del (p.Thr1037fs)	Likely pathogenic
2636287	NM_032387.5(WNK4):c.1675GAG[1] (p.Glu560del)	Likely pathogenic
7661	NM_032387.5(WNK4):c.1684G>A (p.Glu562Lys)	Likely pathogenic

SpliceAI

3086 predictions. Top by Δscore:

Variant	Effect	Δscore
17:42781293:G:GT	donor_gain	1.0000
17:42782753:CACA:C	acceptor_loss	1.0000
17:42782755:CAGAC:C	acceptor_loss	1.0000
17:42782756:A:AG	acceptor_gain	1.0000
17:42782756:A:T	acceptor_loss	1.0000
17:42782757:G:A	acceptor_loss	1.0000
17:42782757:G:GA	acceptor_gain	1.0000
17:42782859:G:GT	donor_gain	1.0000
17:42782928:G:GT	donor_gain	1.0000
17:42782928:GAC:G	donor_gain	1.0000
17:42782931:G:GG	donor_gain	1.0000
17:42784172:G:GT	donor_gain	1.0000
17:42784420:A:AG	acceptor_gain	1.0000
17:42784421:G:GG	acceptor_gain	1.0000
17:42785172:GA:G	donor_gain	1.0000
17:42785465:G:GT	donor_gain	1.0000
17:42785479:GATG:G	donor_gain	1.0000
17:42785483:G:GG	donor_gain	1.0000
17:42785513:G:GT	donor_gain	1.0000
17:42785524:G:GT	donor_gain	1.0000
17:42785554:G:T	donor_gain	1.0000
17:42788361:G:GT	donor_gain	1.0000
17:42788362:G:T	donor_gain	1.0000
17:42788406:GT:G	donor_gain	1.0000
17:42796319:CCTG:C	donor_loss	1.0000
17:42796321:TGGTG:T	donor_loss	1.0000
17:42796323:G:GC	donor_loss	1.0000
17:42796324:T:G	donor_loss	1.0000
17:42796546:G:GT	donor_gain	1.0000
17:42796574:GGATG:G	donor_gain	1.0000

AlphaMissense

7983 scored. Top likely-pathogenic:

Variant	Protein change	am_pathogenicity
17:42781219:T:C	L174P	1.000
17:42781224:T:C	F176L	1.000
17:42781226:T:A	F176L	1.000
17:42781226:T:G	F176L	1.000
17:42781302:T:A	W202R	1.000
17:42781302:T:C	W202R	1.000
17:42781304:G:C	W202C	1.000
17:42781304:G:T	W202C	1.000
17:42781305:T:C	C203R	1.000
17:42781307:T:G	C203W	1.000
17:42782792:T:C	F218S	1.000
17:42782813:T:C	L225P	1.000
17:42783983:T:A	W280R	1.000
17:42783983:T:C	W280R	1.000
17:42784062:A:T	D306V	1.000
17:42784070:T:C	F309L	1.000
17:42784071:T:C	F309S	1.000
17:42784072:T:A	F309L	1.000
17:42784072:T:G	F309L	1.000
17:42784074:T:A	I310N	1.000
17:42784095:T:A	V317D	1.000
17:42784103:G:A	G320R	1.000
17:42784103:G:C	G320R	1.000
17:42784103:G:T	G320W	1.000
17:42784104:G:A	G320E	1.000
17:42784107:A:C	D321A	1.000
17:42784107:A:G	D321G	1.000
17:42784107:A:T	D321V	1.000
17:42784112:G:C	G323R	1.000
17:42784433:T:C	F342L	1.000

dbSNP variants (sampled 300 via entrez): RS1000138524 (17:42787080 T>C), RS1000356260 (17:42781317 G>A), RS1000781790 (17:42791532 G>A), RS1000961825 (17:42780305 T>A), RS1001430576 (17:42780138 G>A), RS1001603403 (17:42783706 C>G,T), RS1001645431 (17:42782439 C>T), RS1002167047 (17:42787238 G>A,T), RS1002605839 (17:42784897 G>A), RS1002808861 (17:42779582 T>C), RS1002953265 (17:42797281 C>A,T), RS1003005910 (17:42791877 G>A), RS1003116810 (17:42791483 T>C), RS1003454054 (17:42789792 G>T), RS1003723247 (17:42783768 C>T)

Disease associations

OMIM: gene MIM:601844 | disease phenotypes: MIM:614491

GenCC curated gene-disease

Disease	Classification	Inheritance
pseudohypoaldosteronism type 2B	Strong	Autosomal dominant

Mondo (2): pseudohypoaldosteronism type 2B (MONDO:0013777), connective tissue disorder (MONDO:0003900)

Orphanet (2): Pseudohypoaldosteronism type 2 (Orphanet:757), Pseudohypoaldosteronism type 2B (Orphanet:88939)

HPO phenotypes

6 total (6 of 6 shown, HPO-id order):

HPO	Term
HP:0000006	Autosomal dominant inheritance
HP:0000822	Hypertension
HP:0002153	Hyperkalemia
HP:0004918	Hyperchloremic metabolic acidosis
HP:0008242	Pseudohypoaldosteronism
HP:0011423	Hyperchloremia

GWAS associations

0 associations (top):

MeSH disease descriptors (2)

Descriptor	Name	Tree numbers
D003240	Connective Tissue Diseases	C17.300
C564161	Pseudohypoaldosteronism, Type IIb (supp.)

Drugs & pharmacology

Drug and pharmacology data

Is drug target: yes

ChEMBL targets (1): CHEMBL1795196 (SINGLE PROTEIN)

PharmGKB: 1 entry (VIP=true, CPIC=false)

GtoPdb / IUPHAR curated pharmacology

(IUPHAR/BPS Guide to Pharmacology — expert-curated)

Target class: enzyme — Wnk family

PubChem BioAssay actives

1 with measured affinity, of 64 total; 1 most potent distinct compounds. Largely complementary to BindingDB; screening values are coarse (µM, 4 dp), so sub-nM hits tie at the floor.

Compound	Assay	Type	Value	Unit
[2-[(4-chlorophenyl)methoxy]phenyl]-[5-[2-(methylamino)-1,3-thiazol-4-yl]-2,3-dihydroindol-1-yl]methanone	1802280: WNK In Vitro Radiometric Assays from Article 10.1021/acschembio.6b00511: “Discovery and Characterization of Allosteric WNK Kinase Inhibitors.”	ic50	0.1870	uM

CTD chemical–gene interactions

37 total (human), top 30 by PubMed support.

Chemical	Actions (top 5)	PubMed papers
Silicon Dioxide	decreases expression	2
Aflatoxin B1	decreases methylation, increases methylation	2
aristolochic acid I	increases expression	1
dicrotophos	increases expression	1
pirinixic acid	affects binding, increases activity, increases expression	1
2,2’-methylenebis(4-methyl-6-tert-butylphenol)	affects response to substance, affects expression	1
methylparaben	increases expression	1
sodium arsenite	increases abundance, affects cotreatment, decreases expression	1
manganese chloride	affects cotreatment, decreases expression, increases abundance	1
nickel sulfate	increases expression	1
butylparaben	increases expression	1
perfluorooctane sulfonic acid	increases expression	1
2-palmitoylglycerol	increases expression	1
abrine	increases expression	1
Leflunomide	increases expression	1
Acetaminophen	increases expression	1
Air Pollutants	increases abundance, increases expression	1
Arsenic	affects cotreatment, decreases expression, increases abundance	1
Benzo(a)pyrene	decreases methylation	1
Caffeine	increases phosphorylation	1
Cisplatin	decreases response to substance	1
Diethylhexyl Phthalate	increases expression	1
Estradiol	affects cotreatment, increases expression	1
Hydrogen Peroxide	affects expression	1
Manganese	affects cotreatment, decreases expression, increases abundance	1
Smoke	decreases expression	1
Thiram	increases expression	1
Toluene	decreases methylation, increases expression	1
Valproic Acid	increases methylation	1
Vanadates	decreases expression	1

ChEMBL screening assays

63 unique, capped per target: 63 binding

Representative assays (with source publication via chembl_document):

Assay ID	Type	Description	Source paper
CHEMBL1838138	Binding	Inhibition of human Wnk4 in HL60 cells lysate at 10 uM using post probe-labeling by LC-MS/MS analysis relative to control	Synthesis and structure-activity relationship of 4-quinolone-3-carboxylic acid based inhibitors of glycogen synthase kinase-3β. — Bioorg Med Chem Lett

Cellosaurus cell lines

2 cell lines: 2 cancer cell line

First 10 cell lines (id-ordered, not curated):

Cellosaurus	Name	Category	Sex
CVCL_TY16	HAP1 WNK4 (-) 1	Cancer cell line	Male
CVCL_TY17	HAP1 WNK4 (-) 2	Cancer cell line	Male

Clinical trials (associated diseases)

83 trials via MONDO — disease-level, not drug-specific.

Trial	Phase	Status	Title
NCT01042158	PHASE4	COMPLETED	A Clinical Trial of Ambrisentan and Tadalafil in Pulmonary Arterial Hypertension Associated With Systemic Sclerosis
NCT03688191	PHASE4	UNKNOWN	Study of Sirolimus in CTD-TP in China
NCT04169100	PHASE4	UNKNOWN	Novel Form of Acquired Long QT Syndrome
NCT04197050	PHASE4	UNKNOWN	Effect of Sacubitril/Valsartan on Reduced Right Ventricular Ejection Fraction in Patients With CTD
NCT04928586	PHASE4	UNKNOWN	Immunosuppressant Combined With Pirfenidone in CTD-ILD
NCT05440240	PHASE4	RECRUITING	Percutaneous Needle Fasciotomy +/- Corticosteroid Injection for Dupuytren’s Contracture
NCT05505409	PHASE4	UNKNOWN	Efficacy and Safety of Pirfenidone in CTD-ILD
NCT06499233	PHASE4	RECRUITING	Efficacy and Safety of Prophylactic Treatment for Pneumocystis Jirovecii Pneumonia in Patients With Autoimmune Inflammatory Rheumatic Disease
NCT00864201	PHASE3	UNKNOWN	A Study to Evaluate the Use of Bosentan in Patients With Exercise Induced Pulmonary Arterial Hypertension Associated With Connective Tissue Disease
NCT01196091	PHASE3	COMPLETED	A Study of LY2127399 in Participants With Systemic Lupus Erythematosus
NCT01205438	PHASE3	COMPLETED	A Study of LY2127399 in Participants With Systemic Lupus Erythematosus
NCT01488708	PHASE3	TERMINATED	On Open-Label Study in Participants With Systemic Lupus Erythematosus
NCT03626688	PHASE3	COMPLETED	A Study Evaluating the Efficacy and Safety of Ralinepag to Improve Treatment Outcomes in PAH Patients
NCT03683186	PHASE3	ENROLLING_BY_INVITATION	A Study Evaluating the Long-Term Efficacy and Safety of Ralinepag in Subjects With PAH Via an Open-Label Extension
NCT04084678	PHASE3	TERMINATED	A Study of Ralinepag to Evaluate Effects on Exercise Capacity by CPET in Subjects With WHO Group 1 PH
NCT06716606	PHASE3	RECRUITING	A Study to Investigate the Long-term Safety and Efficacy of Belimumab in Adults With Interstitial Lung Disease (ILD) Associated With Systemic Sclerosis (SSc) and Other Connective Tissue Diseases (CTD) (BLISSconneCTD-OLE)
NCT06917690	PHASE3	RECRUITING	A Study to Learn About the Safety and Efficacy of the Drug Oleogel-S10 in Japanese Patients With Epidermolysis Bullosa
NCT00004357	PHASE2	COMPLETED	Absorption of Corticosteroids in Children With Juvenile Dermatomyositis
NCT00005675	PHASE2	COMPLETED	Oral Type I Collagen for Relieving Scleroderma
NCT01808196	PHASE2	COMPLETED	Testing Effectiveness of Losartan in Patients With EoE With or Without a CTD
NCT02682511	PHASE2	ACTIVE_NOT_RECRUITING	Oral Ifetroban to Treat Diffuse Cutaneous Systemic Sclerosis (SSc) or SSc-associated Pulmonary Arterial Hypertension
NCT04993885	PHASE2	RECRUITING	Avatrombopag in the Treatment of Adult Immune Thrombocytopenia With Autoantibodies
NCT05516758	PHASE2	TERMINATED	A Study of Peresolimab (LY3462817) in Participants With Moderately-to-Severely Active Rheumatoid Arthritis
NCT05998759	PHASE2	RECRUITING	Telitacicept for the Treatment of Connective Tissue Disease-associated Thrombocytopenia
NCT06104228	PHASE2	RECRUITING	129 Xenon MRI as a Biomarker for Diagnosis and Response to Therapy in Pulmonary Arterial Hypertension (PAH)
NCT01093911	PHASE1	COMPLETED	Safety Study of CDP7657 in Healthy Volunteers and Patients With Systemic Lupus Erythematosus (SLE)
NCT01764594	PHASE1	COMPLETED	Safety Study of CDP7657 in Patients With Systemic Lupus Erythematosus
NCT02392130	PHASE1	COMPLETED	A Clinical Trial to Assess the Potential of LEO 130852A Gel to Reduce Steroid Induced Skin Atrophy on Healthy Skin
NCT03337165	PHASE1	COMPLETED	Autologous Tolerogenic Dendritic Cells for Treatment of Patients With Rheumatoid Arthritis
NCT03929120	PHASE1	COMPLETED	Allogeneic Bone Marrow Mesenchymal Stem Cells for Patients With Interstitial Lung Disease (ILD) & Connective Tissue Disorders (CTD)
NCT01424033	PHASE2/PHASE3	TERMINATED	A Clinical Trial for CTD-ILD Treatment
NCT04915482	PHASE2/PHASE3	UNKNOWN	TPO-RAs Combined With Anti-CD20 Antibody in the Treatment of Adult Immune Thrombocytopenia With Autoantibodies
NCT06574581	PHASE1/PHASE2	RECRUITING	ADSCs Therapy in Patients With CTD-ILD
NCT00001330	Not specified	COMPLETED	Study of Silicone-Associated Connective Tissue Diseases
NCT00001641	Not specified	COMPLETED	Study of Heritable Connective Tissue Disorders
NCT00001978	Not specified	TERMINATED	Determination of Kidney Function
NCT00076830	Not specified	COMPLETED	Evaluation and Treatment of Patients With Connective Tissue Disease
NCT00341679	Not specified	COMPLETED	Studies of the Natural History and Pathogenesis of Autoimmune/Connective Tissue Diseases
NCT00470327	Not specified	RECRUITING	A Study of the Natural Progression of Interstitial Lung Disease (ILD)
NCT00491309	Not specified	UNKNOWN	Exercise and Respiratory Therapy in Patients With Rheumatoid Arthritis / Collagenosis and Pulmonary Hypertension