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FLASH GENE
Symbol KCNJ2 contributors: mct/npt/pgu - updated : 20-12-2018
HGNC name potassium inwardly-rectifying channel, subfamily J, member 2
HGNC id 6263
Corresponding disease
ATFB9 atrial fibrillation, familial, 9
PPKCA Andersen cardiodysrhythmic periodic paralysis
SQT3 short QT syndrome-3
Location 17q24.3      Physical location : 68.165.675 - 68.176.181
Synonym name
  • inward rectifier K+ channel KIR2.1
  • cardiac inward rectifier potassium channel
  • Synonym symbol(s) IRK1, KIR2.1, HHIRK1, LQT7, HHBIRK1, HIRK1, ATFB9, SQT3
    DNA
    TYPE functioning gene
    STRUCTURE 10.51 kb     2 Exon(s)
    10 Kb 5' upstream gene genomic sequence study
    MAPPING cloned Y linked N status inconsistent : contradictory evidence
    RNA
    TRANSCRIPTS type messenger
    identificationnb exonstypebpproduct
    ProteinkDaAAspecific expressionYearPubmed
    2 - 5397 - 427 - 1995 7590287
    EXPRESSION
    Type
       expressed in (based on citations)
    organ(s)
    SystemOrgan level 1Organ level 2Organ level 3Organ level 4LevelPubmedSpeciesStageRna symbol
    Cardiovascularheart     Homo sapiens
    Digestiveintestinesmall intestine   
    Endocrineparathyroid    
    Respiratoryrespiratory tractlarynx   
    Urinarykidneynephron   
    tissue
    SystemTissueTissue level 1Tissue level 2LevelPubmedSpeciesStageRna symbol
    Epithelialbarrier/liningcorneal epithelium  
    Epithelialsensoryvisual  
    Muscularstriatumskeletal   Homo sapiens
    Muscularstriatumcardiac   Homo sapiens
    cells
    SystemCellPubmedSpeciesStageRna symbol
    Blood/Hematopoieticneutrophil Mus musculus
    Muscularmyocyte Homo sapiens
    cell lineage
    cell lines
    fluid/secretion
    at STAGE
    physiological period pregnancy
    Text placenta
    PROTEIN
    PHYSICAL PROPERTIES
    STRUCTURE
    motifs/domains
  • two membrane-spanning domains
  • an amphipatic region pore, including the P domain with the K+ channel signature
  • an ATP-binding regulatory domain
  • a PIP2 binding membrane-associated domain
  • a cytoplasmic segment that is highly energetically unfavorable for cholesterol binding
  • type I PDZ recognition motif at the extreme C terminus mediating interaction with all three PDZ domains of PSD-93delta
  • mono polymer homomer , tetramer
    HOMOLOGY
    interspecies homolog to murine MIrk1
    Homologene
    FAMILY
  • inward rectifier-type potassium channel family
  • CATEGORY transport channel
    SUBCELLULAR LOCALIZATION     plasma membrane
        intracellular
    intracellular,cytoplasm,organelle,membrane
    intracellular,cytoplasm,organelle,endoplasmic reticulum
    intracellular,cytoplasm,organelle,Golgi
    basic FUNCTION
  • potassium voltage-gated channel, inwardly rectifying, playing a role in developmental signaling in addition to its function in controlling cell excitability in skeletal muscle and heart
  • responsible for controlling membrane excitability in many cell types
  • KCNJ2 and KCNJ12 are primary determinants of endogenous K(+) conductance in aortic endothelial cells under resting conditions and KCNJ12 provides the dominant conductance in these cells
  • plays a critical role in modulating excitability by setting the resting membrane potential and shaping phase 3 of the cardiac action potential
  • KCNJ2 and KCNJ12 have two distinct lipid requirements for activity: a specific requirement for INPP5J and a nonspecific requirement for anionic phospholipids
  • participates in the maintenance of the cell membrane potential in a variety of cells including neurons and cardiac myocytes
  • KCNJ2 channels are selected for export from the Golgi in a signal-dependent manner through an AP1 clathrin adaptor interaction
  • normal KCNJ2 channel function is essential during osteoblastogenesis
  • may participate in macrophage maturation and differentiation, and play a key role in lipid uptake and foam cell formation through modulating the expression of scavenger receptors.
  • plays key roles in regulation of resting membrane potential and cell excitability
  • CELLULAR PROCESS
    PHYSIOLOGICAL PROCESS development
    text ion transport
    PATHWAY
    metabolism
    signaling
    a component
  • CDON forms a complex with KCNJ2 during myogenic differentiation, and is required for the channel activity by enhancing the surface expression of KCNJ2 in the early stage of differentiation
  • INTERACTION
    DNA
    RNA
    small molecule
    protein
  • multiple proteolytic pathways control KCNJ2 levels at the plasma membrane
  • inhibition of KCNJ2 channels increases cell mobility without affecting cell cycling progression in human cardiac KIT progenitor cells
  • STK39 and OXSR1 are both stimulators of KCNJ2 activity, and they are presumably effective by enhancing channel insertion into the cell membrane
  • promyogenic CDON signaling is critical for KCNJ2 activities in the induction of myogenic differentiation
  • cell & other
    REGULATION
    activated by hypoxic stress that up-regulates KCNJ2 expression and facilitates cell proliferation in brain capillary endothelial cells
    inhibited by powerful inhibitory effect of the AMP-activated kinase AMPK on the widely expressed inwardly rectifying K+ channel KCNJ2
    Other ATP regulated
    regulated by nitric oxide (NO) (under physiological conditions, NO regulates KCNJ2 through a redox-related process)
    is targeted for endoplasmic reticulum-associated degradation (ERAD)
    ASSOCIATED DISORDERS
    corresponding disease(s) PPKCA , SQT3 , ATFB9
    Other morbid association(s)
    TypeGene ModificationChromosome rearrangementProtein expressionProtein Function
    constitutional   translocation    
    non-syndromic Pierre-robin sequence may be caused by both SOX9 and KCNJ2 dysregulation in a patient with t(2;17)
    constitutional germinal mutation      
    cause a similar constellation of birth defects as in Fetal alcohol spectrum disorder (FASD), and alcohol targets likely KCNJ2 to cause the birth defects associated
    Susceptibility
    Variant & Polymorphism
    Candidate gene
    Marker
    Therapy target
    SystemTypeDisorderPubmed
    cardiovascularatheroma 
    may be a potential therapeutic target in the treatment of cardiovascular diseases, such as atherosclerosis and restenosis following percutaneous coronary intervention
    ANIMAL & CELL MODELS