WNK1 : WNK lysine deficient protein kinase 1

Description

The WNK1 (WNK lysine deficient protein kinase 1) is a protein-coding gene located on chromosome 12.

The WNK1 gene provides instructions for making multiple versions (isoforms) of the WNK1 protein. The different WNK1 isoforms are important in several functions in the body, including blood pressure regulation and pain sensation.One isoform produced from the WNK1 gene is the full-length version, called the L-WNK1 protein, which is found in cells throughout the body. A different isoform, called the kidney-specific WNK1 protein or KS-WNK1, is found only in kidney cells. The L-WNK1 and KS-WNK1 proteins act as kinases, which are enzymes that change the activity of other proteins by adding a cluster of oxygen and phosphorus atoms (a phosphate group) at specific positions.The L-WNK1 and KS-WNK1 proteins regulate channels in the cell membrane that control the transport of sodium or potassium into and out of cells. In the kidneys, sodium channels help transport sodium into specialized cells, which then transfer it into the blood. This transfer helps keep sodium in the body through a process called reabsorption. Potassium channels handle excess potassium that has been transferred from the blood into kidney cells. The channels transport potassium out of the cells in a process called secretion, so that it can be removed from the body in urine.The L-WNK1 protein increases sodium reabsorption and decreases potassium secretion, whereas the KS-WNK1 protein has the opposite effect. Sodium and potassium are important for regulating blood pressure, and a balance of L-WNK1 protein and KS-WNK1 protein in the kidneys helps maintain the correct levels of sodium and potassium for healthy blood pressure.Another isoform produced from the WNK1 gene, called the WNK1/HSN2 protein, is found in the cells of the nervous system, including nerve cells that transmit the sensations of pain, temperature, and touch (sensory neurons). The WNK1/HSN2 protein appears to regulate channels in the cell membrane that can transport negatively charged chlorine atoms (chloride ions). These channels maintain the proper amount of chloride inside cells, which is important for controlling the activation (excitation) of the neurons.

Serine/threonine-protein kinase component of the WNK1- SPAK/OSR1 kinase cascade, which acts as a key regulator of blood pressure and regulatory volume increase by promoting ion influx. WNK1 mediates regulatory volume increase in response to hyperosmotic stress by acting as a molecular crowding sensor, which senses cell shrinkage and mediates formation of a membraneless compartment by undergoing liquid-liquid phase separation. The membraneless compartment concentrates WNK1 with its substrates, OXSR1/OSR1 and STK39/SPAK, promoting WNK1-dependent phosphorylation and activation of downstream kinases OXSR1/OSR1 and STK39/SPAK. Following activation, OXSR1/OSR1 and STK39/SPAK catalyze phosphorylation of ion cotransporters SLC12A1/NKCC2, SLC12A2/NKCC1, SLC12A5/KCC2 and SLC12A6/KCC3, regulating their activity. Phosphorylation of Na-K-Cl cotransporters SLC12A2/NKCC1 and SLC12A2/NKCC1 promote their activation and ion influx; simultaneously, phosphorylation of K-Cl cotransporters SLC12A5/KCC2 and SLC12A6/KCC3 inhibit their activity, blocking ion efflux. Also acts as a regulator of angiogenesis in endothelial cells via activation of OXSR1/OSR1 and STK39/SPAK: activation of OXSR1/OSR1 regulates chemotaxis and invasion, while STK39/SPAK regulates endothelial cell proliferation. Also acts independently of the WNK1- SPAK/OSR1 kinase cascade by catalyzing phosphorylation of other substrates, such as SYT2, PCF11 and NEDD4L. Mediates phosphorylation of SYT2, regulating SYT2 association with phospholipids and membrane-binding. Regulates mRNA export in the nucleus by mediating phosphorylation of PCF11, thereby decreasing the association between PCF11 and POLR2A/RNA polymerase II and promoting mRNA export to the cytoplasm. Acts as a negative regulator of autophagy. Required for the abscission step during mitosis, independently of the WNK1-SPAK/OSR1 kinase cascade. May also play a role in actin cytoskeletal reorganization. Also acts as a scaffold protein independently of its protein kinase activity: negatively regulates cell membrane localization of various transporters and channels, such as SLC4A4, SLC26A6, SLC26A9, TRPV4 and CFTR. Involved in the regulation of epithelial Na(+) channel (ENaC) by promoting activation of SGK1 in a kinase-independent manner: probably acts as a scaffold protein that promotes the recruitment of SGK1 to the mTORC2 complex in response to chloride, leading to mTORC2-dependent phosphorylation and activation of SGK1. Acts as an assembly factor for the ER membrane protein complex independently of its protein kinase activity: associates with EMC2 in the cytoplasm via its amphipathic alpha-helix, and prevents EMC2 ubiquitination and subsequent degradation, thereby promoting EMC2 stabilization.

WNK1 is also known as HSAN2, HSN2, KDP, PPP1R167, PRKWNK1, PSK, p65.

Associated Diseases

Comprehensive carrier screening

WES Whole Exome Sequencing

Clinical Exome Sequencing