The ERKs are a subfamily of the MAPKs that have been implicated in cell growth and differentiation. By using the rat ERK7 cDNA to screen a human multiple tissue cDNA library, we identified a new member of the ERK family, ERK8, that shares 69% amino acid sequence identity with ERK7. Northern analysis demonstrates that ERK8 is present in a number of tissues with maximal expression in the lung and kidney. Fluorescence in situ hybridization localized the ERK8 gene to chromosome 8, band q24.3. Expression of ERK8 in COS cells and bacteria indicates that, in contrast to constitutively active ERK7, ERK8 has minimal basal kinase activity and a unique substrate profile. ERK8, which contains two SH3-binding motifs in its C-terminal region, associates with the c-Src SH3 domain in vitro and co-immunoprecipitates with c-Src in vivo. Co-transfection with either v-Src or a constitutively active c-Src increases ERK8 activation indicating that ERK8 can be activated downstream of c-Src. ERK8 is also activated following serum stimulation, and the extent of this activation is reduced by pretreatment with the specific Src family inhibitor PP2. The ERK8 activation by serum or Src was not affected by the MEK inhibitor U0126 indicating that activation of ERK8 does not require MEK1, MEK2, or MEK5. Although most closely related to ERK7, the relatively low sequence identity, minimal basal activity, and different substrate profile identify ERK8 as a distinct member of the MAPK family that is activated by an Src-dependent signaling pathway.
Mitogen-activated protein (MAP) kinases have a central role in several biological functions, including cell adhesion and spreading, chemotaxis, cell cycle progression, differentiation, and apoptosis. Extracellular signal-regulated kinase 8 (Erk8) is a large MAP kinase whose activity is controlled by serum and the c-Src non-receptor tyrosine kinase. Here, we show that RET/PTC3, an activated form of the RET proto-oncogene, was able to activate Erk8, and we demonstrate that such MAP kinase participated in RET/PTC3-dependent stimulation of the c-jun promoter. By using RET/PTC3 molecules mutated in specific tyrosine autophosphorylation sites, we characterized Tyr(981), a known binding site for c-Src, as a major determinant of RET/PTC3-induced Erk8 activation, although, surprisingly, the underlying mechanism did not strictly depend on the activity of Src. In contrast, we present evidence that RET/PTC3 acts on Erk8 through Tyr(981)-mediated activation of c-Abl. Furthermore, we localized the region responsible for the modulation of Erk8 activity by the RET/PTC3 and Abl oncogenes in the Erk8 C-terminal domain. Altogether, these results support a role for Erk8 as a novel effector of RET/PTC3 and, therefore, RET biological functions.
Catalysis of the reaction: protein + ATP = protein phosphate + ADP. This reaction is the phosphorylation of proteins. Mitogen-activated protein kinase; a family of protein kinases that perform a crucial step in relaying signals from the plasma membrane to the nucleus. They are activated by a wide range of proliferation- or differentiation-inducing signals; activation is strong with agonists such as polypeptide growth factors and tumor-promoting phorbol esters, but weak (in most cell backgrounds) by stress stimuli.
The ERKs are a subfamily of the MAPKs that have been implicated in cell growth and differentiation. By using the rat ERK7 cDNA to screen a human multiple tissue cDNA library, we identified a new member of the ERK family, ERK8, that shares 69% amino acid sequence identity with ERK7. Northern analysis demonstrates that ERK8 is present in a number of tissues with maximal expression in the lung and kidney. Fluorescence in situ hybridization localized the ERK8 gene to chromosome 8, band q24.3. Expression of ERK8 in COS cells and bacteria indicates that, in contrast to constitutively active ERK7, ERK8 has minimal basal kinase activity and a unique substrate profile. ERK8, which contains two SH3-binding motifs in its C-terminal region, associates with the c-Src SH3 domain in vitro and co-immunoprecipitates with c-Src in vivo. Co-transfection with either v-Src or a constitutively active c-Src increases ERK8 activation indicating that ERK8 can be activated downstream of c-Src. ERK8 is also activated following serum stimulation, and the extent of this activation is reduced by pretreatment with the specific Src family inhibitor PP2. The ERK8 activation by serum or Src was not affected by the MEK inhibitor U0126 indicating that activation of ERK8 does not require MEK1, MEK2, or MEK5. Although most closely related to ERK7, the relatively low sequence identity, minimal basal activity, and different substrate profile identify ERK8 as a distinct member of the MAPK family that is activated by an Src-dependent signaling pathway.
Interacting selectively and non-covalently with a SH3 domain (Src homology 3) of a protein, small protein modules containing approximately 50 amino acid residues found in a great variety of intracellular or membrane-associated proteins.
The ERKs are a subfamily of the MAPKs that have been implicated in cell growth and differentiation. By using the rat ERK7 cDNA to screen a human multiple tissue cDNA library, we identified a new member of the ERK family, ERK8, that shares 69% amino acid sequence identity with ERK7. Northern analysis demonstrates that ERK8 is present in a number of tissues with maximal expression in the lung and kidney. Fluorescence in situ hybridization localized the ERK8 gene to chromosome 8, band q24.3. Expression of ERK8 in COS cells and bacteria indicates that, in contrast to constitutively active ERK7, ERK8 has minimal basal kinase activity and a unique substrate profile. ERK8, which contains two SH3-binding motifs in its C-terminal region, associates with the c-Src SH3 domain in vitro and co-immunoprecipitates with c-Src in vivo. Co-transfection with either v-Src or a constitutively active c-Src increases ERK8 activation indicating that ERK8 can be activated downstream of c-Src. ERK8 is also activated following serum stimulation, and the extent of this activation is reduced by pretreatment with the specific Src family inhibitor PP2. The ERK8 activation by serum or Src was not affected by the MEK inhibitor U0126 indicating that activation of ERK8 does not require MEK1, MEK2, or MEK5. Although most closely related to ERK7, the relatively low sequence identity, minimal basal activity, and different substrate profile identify ERK8 as a distinct member of the MAPK family that is activated by an Src-dependent signaling pathway.
An intracellular protein kinase cascade containing at least a MAPK, a MAPKK and a MAP3K. The cascade can also contain two additional tiers: the upstream MAP4K and the downstream MAP Kinase-activated kinase (MAPKAPK). The kinases in each tier phosphorylate and activate the kinases in the downstream tier to transmit a signal within a cell.
The ERKs are a subfamily of the MAPKs that have been implicated in cell growth and differentiation. By using the rat ERK7 cDNA to screen a human multiple tissue cDNA library, we identified a new member of the ERK family, ERK8, that shares 69% amino acid sequence identity with ERK7. Northern analysis demonstrates that ERK8 is present in a number of tissues with maximal expression in the lung and kidney. Fluorescence in situ hybridization localized the ERK8 gene to chromosome 8, band q24.3. Expression of ERK8 in COS cells and bacteria indicates that, in contrast to constitutively active ERK7, ERK8 has minimal basal kinase activity and a unique substrate profile. ERK8, which contains two SH3-binding motifs in its C-terminal region, associates with the c-Src SH3 domain in vitro and co-immunoprecipitates with c-Src in vivo. Co-transfection with either v-Src or a constitutively active c-Src increases ERK8 activation indicating that ERK8 can be activated downstream of c-Src. ERK8 is also activated following serum stimulation, and the extent of this activation is reduced by pretreatment with the specific Src family inhibitor PP2. The ERK8 activation by serum or Src was not affected by the MEK inhibitor U0126 indicating that activation of ERK8 does not require MEK1, MEK2, or MEK5. Although most closely related to ERK7, the relatively low sequence identity, minimal basal activity, and different substrate profile identify ERK8 as a distinct member of the MAPK family that is activated by an Src-dependent signaling pathway.
Any process that activates or increases the frequency, rate or extent of the chemical reactions and pathways resulting in the breakdown of a protein by the destruction of the native, active configuration, with or without the hydrolysis of peptide bonds.
The ERKs are a subfamily of the MAPKs that have been implicated in cell growth and differentiation. By using the rat ERK7 cDNA to screen a human multiple tissue cDNA library, we identified a new member of the ERK family, ERK8, that shares 69% amino acid sequence identity with ERK7. Northern analysis demonstrates that ERK8 is present in a number of tissues with maximal expression in the lung and kidney. Fluorescence in situ hybridization localized the ERK8 gene to chromosome 8, band q24.3. Expression of ERK8 in COS cells and bacteria indicates that, in contrast to constitutively active ERK7, ERK8 has minimal basal kinase activity and a unique substrate profile. ERK8, which contains two SH3-binding motifs in its C-terminal region, associates with the c-Src SH3 domain in vitro and co-immunoprecipitates with c-Src in vivo. Co-transfection with either v-Src or a constitutively active c-Src increases ERK8 activation indicating that ERK8 can be activated downstream of c-Src. ERK8 is also activated following serum stimulation, and the extent of this activation is reduced by pretreatment with the specific Src family inhibitor PP2. The ERK8 activation by serum or Src was not affected by the MEK inhibitor U0126 indicating that activation of ERK8 does not require MEK1, MEK2, or MEK5. Although most closely related to ERK7, the relatively low sequence identity, minimal basal activity, and different substrate profile identify ERK8 as a distinct member of the MAPK family that is activated by an Src-dependent signaling pathway.
Any process that results in a change in state or activity of a cell or an organism (in terms of movement, secretion, enzyme production, gene expression, etc.) as a result of stimulus by estradiol, a C18 steroid hormone hydroxylated at C3 and C17 that acts as a potent estrogen.
IEAOrtholog Compara
Enzymatic activity
This protein acts as an enzyme. It is known to catalyze the following reaction
Protein which catalyzes the phosphorylation of serine or threonine residues on target proteins by using ATP as phosphate donor. Such phosphorylation may cause changes in the function of the target protein. Protein kinases share a conserved catalytic core common to both serine/ threonine and tyrosine protein kinases.
A reference proteome is a set of protein sequences derived from a complete proteome which constitutes a defined standard for a particular user community. Reference proteomes are manually defined according to a number of criteria. They cover the proteomes of well- studied model organisms and other proteomes of interest for biomedical and biotechnological research. Reference proteomes have been selected to provide broad coverage of the tree of life, and constitute a representative cross-section of the taxonomic diversity to be found within UniProtKB.