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C-Jun N-terminal Kinases
c-Jun N-terminal kinases (JNKs), were originally identified as kinases that bind and phosphorylate c-Jun on Ser-63 and Ser-73 within its transcriptional activation domain. They belong to the mitogen-activated protein kinase family, and are responsive to stress stimuli, such as cytokines, ultraviolet irradiation, heat shock, and osmotic shock. They also play a role in T cell differentiation and the cellular apoptosis pathway. Activation occurs through a dual phosphorylation of threonine (Thr) and tyrosine (Tyr) residues within a Thr-Pro-Tyr motif located in kinase subdomain VIII. Activation is carried out by two MAP kinase kinases, MKK4 and MKK7, and JNK can be inactivated by Ser/Thr and Tyr protein phosphatases. It has been suggested that this signaling pathway contributes to inflammatory responses in mammals and insects. Isoforms The c-Jun N-terminal kinases consist of ten isoforms derived from three genes: JNK1 (four isoforms), JNK2 (four isoforms) and JNK3 (two iso ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
MAPK8
Mitogen-activated protein kinase 8 (also known as JNK1) is a ubiquitous enzyme that in humans is encoded by the ''MAPK8'' gene. Function The protein encoded by this gene is a member of the MAP kinase and JNK family. MAP kinases act as an integration point for multiple biochemical signals, and are involved in a wide variety of cellular processes such as proliferation, differentiation, transcription regulation and development. This kinase is activated by various cell stimuli, and targets specific transcription factors, and thus mediates immediate-early gene expression in response to cell stimuli. The activation of this kinase by tumor-necrosis factor alpha (TNF-alpha) is found to be required for TNF-alpha-induced apoptosis. This kinase is also involved in UV radiation-induced apoptosis, which is thought to be related to the cytochrome c-mediated cell death pathway. Studies of the mouse counterpart of this gene suggested that this kinase play a key role in T cell prolif ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
MKK4
Dual-specificity mitogen-activated protein kinase kinase 4 is an enzyme that in humans is encoded by the ''MAP2K4'' gene. ''MAP2K4'' encodes a dual-specificity kinase that belongs to the Ser/Thr protein kinase family. MAP2K4 phosphorylates MAP kinases in response to various environmental stresses or mitogenic stimuli. MAPK8/JNK1, MAPK9/JNK2, and MAPK14/p38 are substrates for MAP2K4, but MAPK1/ERK2 and MAPK3/ERK1 are not phosphorylated by MAP2K4. Structurally, MAP2K4 contains a kinase domain that is phosphorylated and activated by MAP3K1(aka MEKK1). MAP2K4 contains multiple amino acid sites that are phosphorylated and ubiquitinated. Genetic studies using ''Map2k4'' knockout mice revealed embryonic lethality, impaired hepatogenesis and defective liver formation. Analysis of chimeric mice identified a role for ''Map2k4'' in T cell cytokine production and proliferation. ''Map2k4''-deficient chimeric mice frequently develop lymphadenopathy. MAP2K4 is altered in 1.97% of all hu ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Mothers Against Decapentaplegic Homolog 4
SMAD4, also called SMAD family member 4, Mothers against decapentaplegic homolog 4, or DPC4 (Deleted in Pancreatic Cancer-4) is a highly conserved protein present in all metazoans. It belongs to the SMAD family of transcription factor proteins, which act as mediators of TGF-β signal transduction. The TGFβ family of cytokines regulates critical processes during the lifecycle of metazoans, with important roles during embryo development, tissue homeostasis, regeneration, and immune regulation. SMAD 4 belongs to the co-SMAD group (''common mediator'' SMAD), the second class of the SMAD family. SMAD4 is the only known co-SMAD in most metazoans. It also belongs to the Darwin family of proteins that modulate members of the TGFβ protein superfamily, a family of proteins that all play a role in the regulation of cellular responses. Mammalian SMAD4 is a homolog of the ''Drosophila'' protein "Mothers against decapentaplegic" named Medea. SMAD4 interacts with R-Smads, such as SMAD2 ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Activating Transcription Factor 2
Activating transcription factor 2, also known as ATF2, is a protein that, in humans, is encoded by the ''ATF2'' gene. Function This gene encodes a transcription factor that is a member of the leucine zipper family of DNA-binding proteins. This protein binds to the cAMP-responsive element (CRE), an octameric palindrome. The protein forms a homodimer or heterodimer with c-Jun. The protein is also a histone acetyltransferase (HAT) that specifically acetylates histones H2B and H4 in vitro; thus, it may represent a class of sequence-specific factors that activate transcription by direct effects on chromatin components. Additional transcript variants have been identified but their biological validity has not been determined. The gene atf2 is located at human chromosome 2q32. The protein ATF-2 has 505 amino acids. Studies in mice indicate a role for ATF-2 in the development of nervous system and the skeleton. ATF-2 is normally activated in response to signals that converge on stress ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
C-jun
Transcription factor Jun is a protein that in humans is encoded by the ''JUN'' gene. c-Jun, in combination with protein c-Fos, forms the AP-1 early response transcription factor. It was first identified as the Fos-binding protein p39 and only later rediscovered as the product of the JUN gene. c-jun was the first oncogenic transcription factor discovered. The proto-oncogene c-Jun is the cellular homolog of the viral oncoprotein v-jun (). The viral homolog v-jun was discovered in avian sarcoma virus 17 and was named for ''ju-nana'', the Japanese word for 17. The human JUN encodes a protein that is highly similar to the viral protein, which interacts directly with specific target DNA sequences to regulate gene expression. This gene is intronless and is mapped to 1p32-p31, a chromosomal region involved in both translocations and deletions in human malignancies. Function Regulation Both Jun and its dimerization partners in AP-1 formation are subject to regulation by diverse ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
MAP2K7
Dual specificity mitogen-activated protein kinase kinase 7, also known as MAP kinase kinase 7 or MKK7, is an enzyme that in humans is encoded by the ''MAP2K7'' gene. This protein is a member of the mitogen-activated protein kinase kinase family. The MKK7 protein exists as six different isoforms with three possible N-termini (α, β, and γ isoforms) and two possible C-termini (1 and 2 isoforms). MKK7 is involved in signal transduction mediating the cell responses to proinflammatory cytokines, and environmental stresses. This kinase specifically activates MAPK8/JNK1 and MAPK9/JNK2, and this kinase itself is phosphorylated and activated by MAP kinase kinase kinases including MAP3K1/MEKK1, MAP3K2/MEKK2, MAP3K3/MEKK5, and MAP4K2/GCK. MKK7 is ubiquitously expressed in all tissue. However, it displays a higher level of expression in skeletal muscle. Multiple alternatively spliced transcript variants encoding distinct isoforms have been found. Nomenclature MAP2K7 is also kno ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
MAP2K4
Dual-specificity mitogen-activated protein kinase kinase 4 is an enzyme that in humans is encoded by the ''MAP2K4'' gene. ''MAP2K4'' encodes a dual-specificity kinase that belongs to the Ser/Thr protein kinase family. MAP2K4 phosphorylates MAP kinases in response to various environmental stresses or mitogenic stimuli. MAPK8/JNK1, MAPK9/JNK2, and MAPK14/p38 are substrates for MAP2K4, but MAPK1/ERK2 and MAPK3/ERK1 are not phosphorylated by MAP2K4. Structurally, MAP2K4 contains a kinase domain that is phosphorylated and activated by MAP3K1(aka MEKK1). MAP2K4 contains multiple amino acid sites that are phosphorylated and ubiquitinated. Genetic studies using ''Map2k4'' knockout mice revealed embryonic lethality, impaired hepatogenesis and defective liver formation. Analysis of chimeric mice identified a role for ''Map2k4'' in T cell cytokine production and proliferation. ''Map2k4''-deficient chimeric mice frequently develop lymphadenopathy. MAP2K4 is altered in 1.97% of a ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
JNK Interacting Proteins
c-Jun N-terminal kinases (JNKs), were originally identified as kinases that bind and phosphorylate c-Jun on Ser-63 and Ser-73 within its transcriptional activation domain. They belong to the mitogen-activated protein kinase family, and are responsive to stress stimuli, such as cytokines, ultraviolet irradiation, heat shock, and osmotic shock. They also play a role in T cell differentiation and the cellular apoptosis pathway. Activation occurs through a dual phosphorylation of threonine (Thr) and tyrosine (Tyr) residues within a Thr-Pro-Tyr motif located in kinase subdomain VIII. Activation is carried out by two MAP kinase kinases, MKK4 and MKK7, and JNK can be inactivated by Ser/Thr and Tyr protein phosphatases. It has been suggested that this signaling pathway contributes to inflammatory responses in mammals and insects. Isoforms The c-Jun N-terminal kinases consist of ten isoforms derived from three genes: JNK1 (four isoforms), JNK2 (four isoforms) and JNK3 (two isof ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Scaffold Protein
In biology, scaffold proteins are crucial regulators of many key signalling pathways. Although scaffolds are not strictly defined in function, they are known to interact and/or bind with multiple members of a signalling pathway, tethering them into complexes. In such pathways, they regulate signal transduction and help localize pathway components (organized in complexes) to specific areas of the cell such as the plasma membrane, the cytoplasm, the nucleus, the Golgi, endosomes, and the mitochondria. History The first signaling scaffold protein discovered was the Ste5 protein from the yeast ''Saccharomyces cerevisiae''. Three distinct domains of Ste5 were shown to associate with the protein kinases Ste11, Ste7, and Fus3 to form a multikinase complex. Function Scaffold proteins act in at least four ways: tethering signaling components, localizing these components to specific areas of the cell, regulating signal transduction by coordinating positive and negative feedback ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Reactive Oxygen Species
In chemistry, reactive oxygen species (ROS) are highly reactive chemicals formed from diatomic oxygen (). Examples of ROS include peroxides, superoxide, hydroxyl radical, singlet oxygen, and alpha-oxygen. The reduction of molecular oxygen () produces superoxide (), which is the precursor to most other reactive oxygen species: :O2 + e^- -> \ ^\bullet O2- Dismutation of superoxide produces hydrogen peroxide (): :2 H+ + \ ^\bullet O2^- + \ ^\bullet O2^- -> H2O2 + O2 Hydrogen peroxide in turn may be partially reduced, thus forming hydroxide ions and hydroxyl radicals (), or fully reduced to water: :H2O2 + e^- -> HO^- + \ ^\bullet OH :2 H+ + 2 e- + H2O2 -> 2 H2O In a biological context, ROS are byproducts of the normal metabolism of oxygen. ROS have roles in cell signaling and homeostasis. ROS are intrinsic to cellular functioning, and are present at low and stationary levels in normal cells. In plants, ROS are involved in metabolic processes related to photoprotection and toleran ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Exon
An exon is any part of a gene that will form a part of the final mature RNA produced by that gene after introns have been removed by RNA splicing. The term ''exon'' refers to both the DNA sequence within a gene and to the corresponding sequence in RNA transcripts. In RNA splicing, introns are removed and exons are covalently joined to one another as part of generating the mature RNA. Just as the entire set of genes for a species constitutes the genome, the entire set of exons constitutes the exome. History The term ''exon'' derives from the expressed region and was coined by American biochemist Walter Gilbert in 1978: "The notion of the cistron… must be replaced by that of a transcription unit containing regions which will be lost from the mature messengerwhich I suggest we call introns (for intragenic regions)alternating with regions which will be expressedexons." This definition was originally made for protein-coding transcripts that are spliced before being translate ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
