Summary of JAK2
JAK2 is involved in blood cell growth and development, and mutations are the cause of many different blood disorders.
The Function of JAK2
Non-receptor tyrosine kinase involved in various processes such as cell growth, development, differentiation or histone modifications. Mediates essential signaling events in both innate and adaptive immunity. In the cytoplasm, plays a pivotal role in signal transduction via its association with type I receptors such as growth hormone (GHR), prolactin (PRLR), leptin (LEPR), erythropoietin (EPOR), thrombopoietin (THPO); or type II receptors including IFN-alpha, IFN-beta, IFN-gamma and multiple interleukins (PubMed:7615558). Following ligand-binding to cell surface receptors, phosphorylates specific tyrosine residues on the cytoplasmic tails of the receptor, creating docking sites for STATs proteins (PubMed:9618263). Subsequently, phosphorylates the STATs proteins once they are recruited to the receptor. Phosphorylated STATs then form homodimer or heterodimers and translocate to the nucleus to activate gene transcription. For example, cell stimulation with erythropoietin (EPO) during erythropoiesis leads to JAK2 autophosphorylation, activation, and its association with erythropoietin receptor (EPOR) that becomes phosphorylated in its cytoplasmic domain. Then, STAT5 (STAT5A or STAT5B) is recruited, phosphorylated and activated by JAK2. Once activated, dimerized STAT5 translocates into the nucleus and promotes the transcription of several essential genes involved in the modulation of erythropoiesis. In addition, JAK2 mediates angiotensin-2-induced ARHGEF1 phosphorylation (PubMed:20098430). Plays a role in cell cycle by phosphorylating CDKN1B (PubMed:21423214). Cooperates with TEC through reciprocal phosphorylation to mediate cytokine-driven activation of FOS transcription. In the nucleus, plays a key role in chromatin by specifically mediating phosphorylation of 'Tyr-41' of histone H3 (H3Y41ph), a specific tag that promotes exclusion of CBX5 (HP1 alpha) from chromatin (PubMed:19783980).
Recommended name:Tyrosine-protein kinase JAK2
Alternative name(s):Janus kinase 2
- RS10758669 (JAK2) ??
- RS10974944 (JAK2) ??
- RS12339666 (JAK2) ??
- RS12340895 (JAK2) ??
- RS2274471 (JAK2) ??
- RS36051895 (JAK2) ??
- RS3780374 (JAK2) ??
- RS75900472 (JAK2) ??
- RS77375493 (JAK2) ??
- RS7849191 (JAK2) ??
- RS9969783 (JAK2) ??
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Top Gene-Substance Interactions
JAK2 Interacts with These Diseases
Fix/Read: Natural STAT3 Inhibitors- What will inhibit STAT3, will also inhibit JAK2.They are part of the same pathway.
Substances That Increase JAK2
Substances That Decrease JAK2
The JAK2 gene provides instructions for cell growth and division of red blood cells
The JAK2V617F mutation turns that On-Off switch to always On
This group of blood diseases is referred to as Myeloproliferative Neoplasms R
Crohn’s disease is categorized by chronic inflammation of the gut, possibly due to irregular immune response to bacteria in the gut R
White blood cells mistake normal gut bacteria, that aids in digestion, as dangerous and removes it, causing the gut to not properly digest food R
essential thrombocythemia Some gene mutations are acquired during a person's lifetime and are present only in certain cells. These changes, which are called somatic mutations, are not inherited. Somatic mutations in the JAK2 gene are associated with essential thrombocythemia, a disorder characterized by an increased number of platelets, the blood cells involved in normal blood clotting. The most common mutation (written as Val617Phe or V617F) replaces the protein building block (amino acid) valine with the amino acid phenylalanine at position 617 in the protein. This particular mutation is found in approximately half of people with essential thrombocythemia. A small number of affected individuals have a somatic mutation in another part of the JAK2 gene known as exon 12. The V617F JAK2 gene mutation results in the production of a JAK2 protein that is constantly turned on (constitutively activated), which, in essential thrombocythemia, leads to the overproduction of abnormal blood cells called megakaryocytes. Because platelets are formed from megakaryocytes, the overproduction of megakaryocytes results in an increased number of platelets. Excess platelets can cause abnormal blood clotting (thrombosis), which leads to many signs and symptoms of essential thrombocythemia. polycythemia vera Somatic mutations in the JAK2 gene are associated with polycythemia vera, a disorder characterized by uncontrolled blood cell production. The V617F mutation is found in approximately 96 percent of people with polycythemia vera. About 3 percent of affected individuals have a somatic mutation in the exon 12 region of the JAK2 gene. JAK2 gene mutations result in the production of a constitutively activated JAK2 protein, which seems to improve the survival of the cell and increase production of blood cells. With so many extra cells in the bloodstream, abnormal blood clots are more likely to form. In addition, the thicker blood flows more slowly throughout the body, which prevents organs from receiving enough oxygen. Many of the signs and symptoms of polycythemia vera are related to a lack of oxygen in body tissues. primary myelofibrosis Somatic JAK2 gene mutations are also associated with primary myelofibrosis, a condition in which bone marrow is replaced by scar tissue (fibrosis). The V617F mutation is found in approximately half of individuals with primary myelofibrosis. A small number of people with this condition have mutations in the exon 12 region of the gene. These JAK2 gene mutations result in a constitutively active JAK2 protein, which leads to the overproduction of abnormal megakaryocytes. These megakaryocytes stimulate other cells to release collagen, a protein that normally provides structural support for the cells in the bone marrow but causes scar tissue formation in primary myelofibrosis. Because of the fibrosis, the bone marrow cannot produce enough normal blood cells, leading to the signs and symptoms of the condition. other disorders Somatic JAK2 gene mutations are also associated with several related conditions. The V617F mutation is occasionally found in people with cancer of blood-forming cells (leukemia) or other bone marrow disorders. Budd-Chiari syndrome, which results from a blocked vein in the liver, can also be associated with the V617F mutation when it is caused by an underlying bone marrow disorder. It is unknown how one particular mutation can be associated with several conditions.
The JAK2 gene provides instructions for making a protein that promotes the growth and division (proliferation) of cells. This protein is part of a signaling pathway called the JAK/STAT pathway, which transmits chemical signals from outside the cell to the cell's nucleus. The JAK2 protein is especially important for controlling the production of blood cells from hematopoietic stem cells. These stem cells are located within the bone marrow and have the potential to develop into red blood cells, white blood cells, and platelets.
Conditions with Increased Gene Activity
|Condition||Change (log2fold)||Comparison||Species||Experimental variables||Experiment name|
Conditions with Decreased Gene Activity
|Condition||Change (log2fold)||Comparison||Species||Experimental variables||Experiment name|
The following transcription factors affect gene expression:
Ubiquitously expressed throughout most tissues.
Regulated by autophosphorylation, can both activate or decrease activity (By similarity). Heme regulates its activity by enhancing the phosphorylation on Tyr-1007 and Tyr-1008.
Mn(2+) was used in the in vitro kinase assay but Mg(2+) is likely to be the in vivo cofactor.
- Atp Binding
- Growth Hormone Receptor Binding
- Heme Binding
- Histone Binding
- Histone Kinase Activity (H3-Y41 Specific)
- Interleukin-12 Receptor Binding
- Metal Ion Binding
- Non-Membrane Spanning Protein Tyrosine Kinase Activity
- Protein Kinase Binding
- Protein Tyrosine Kinase Activity
- Ras Guanyl-Nucleotide Exchange Factor Activity
- Receptor Binding
- Sh2 Domain Binding
- Actin Filament Polymerization
- Activation Of Cysteine-Type Endopeptidase Activity Involved In Apoptotic Process
- Activation Of Cysteine-Type Endopeptidase Activity Involved In Apoptotic Signaling Pathway
- Activation Of Jak2 Kinase Activity
- Activation Of Mapkk Activity
- Adaptive Immune Response
- Apoptotic Process
- Axon Regeneration
- Blood Coagulation
- Cell Differentiation
- Cytokine-Mediated Signaling Pathway
- Enzyme Linked Receptor Protein Signaling Pathway
- Erythrocyte Differentiation
- Extrinsic Apoptotic Signaling Pathway
- G-Protein Coupled Receptor Signaling Pathway
- Growth Hormone Receptor Signaling Pathway
- Histone H3-Y41 Phosphorylation
- Innate Immune Response
- Interferon-Gamma-Mediated Signaling Pathway
- Interleukin-12-Mediated Signaling Pathway
- Intracellular Signal Transduction
- Intrinsic Apoptotic Signaling Pathway In Response To Oxidative Stress
- Jak-Stat Cascade
- Jak-Stat Cascade Involved In Growth Hormone Signaling Pathway
- Mammary Gland Epithelium Development
- Mapk Cascade
- Mesoderm Development
- Mineralocorticoid Receptor Signaling Pathway
- Movement Of Cell Or Subcellular Component
- Negative Regulation Of Cardiac Muscle Cell Apoptotic Process
- Negative Regulation Of Cell-Cell Adhesion
- Negative Regulation Of Cell Proliferation
- Negative Regulation Of Dna Binding
- Negative Regulation Of Heart Contraction
- Negative Regulation Of Neuron Apoptotic Process
- Peptidyl-Tyrosine Autophosphorylation
- Peptidyl-Tyrosine Phosphorylation
- Platelet-Derived Growth Factor Receptor Signaling Pathway
- Positive Regulation Of Cell Activation
- Positive Regulation Of Cell Differentiation
- Positive Regulation Of Cell Migration
- Positive Regulation Of Cell-Substrate Adhesion
- Positive Regulation Of Cytosolic Calcium Ion Concentration
- Positive Regulation Of Dna Binding
- Positive Regulation Of Epithelial Cell Apoptotic Process
- Positive Regulation Of Growth Factor Dependent Skeletal Muscle Satellite Cell Proliferation
- Positive Regulation Of Growth Hormone Receptor Signaling Pathway
- Positive Regulation Of Inflammatory Response
- Positive Regulation Of Insulin Secretion
- Positive Regulation Of Interleukin-1 Beta Production
- Positive Regulation Of Nitric Oxide Biosynthetic Process
- Positive Regulation Of Nitric-Oxide Synthase Biosynthetic Process
- Positive Regulation Of Peptidyl-Tyrosine Phosphorylation
- Positive Regulation Of Phosphatidylinositol 3-Kinase Signaling
- Positive Regulation Of Phosphoprotein Phosphatase Activity
- Positive Regulation Of Protein Import Into Nucleus, Translocation
- Positive Regulation Of Sequence-Specific Dna Binding Transcription Factor Activity
- Positive Regulation Of Tumor Necrosis Factor Production
- Positive Regulation Of Tyrosine Phosphorylation Of Stat3 Protein
- Positive Regulation Of Tyrosine Phosphorylation Of Stat5 Protein
- Positive Regulation Of Vascular Smooth Muscle Cell Proliferation
- Protein Autophosphorylation
- Protein Phosphorylation
- Regulation Of Apoptotic Process
- Regulation Of Cell Proliferation
- Regulation Of Inflammatory Response
- Regulation Of Interferon-Gamma-Mediated Signaling Pathway
- Response To Antibiotic
- Response To Hydroperoxide
- Response To Interleukin-12
- Response To Lipopolysaccharide
- Response To Tumor Necrosis Factor
- Signal Transduction
- Stat Protein Import Into Nucleus
- Tumor Necrosis Factor-Mediated Signaling Pathway
- Tyrosine Phosphorylation Of Stat1 Protein
- Tyrosine Phosphorylation Of Stat3 Protein
- Tyrosine Phosphorylation Of Stat5 Protein
- Tyrosine Phosphorylation Of Stat Protein
- Positive Regulation Of Cell Proliferation