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Query: EC:2.7.10.1 (
ERK
)
95,504
document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)
As detected by coimmunoprecipitation from PC12 cells,
NGF
induces rapid association between ERK1 (a growth factor-activated serine/threonine protein kinase) and gp140prototrk
NGF
receptors. In contrast, no such association is found with the closely related ERK2. Anti-trk immunocomplexes generated from
NGF
-treated cells also contain protein kinase activity that shares many properties with soluble ERK1. The association of both ERK1 protein and
ERK
-like kinase activity with gp140prototrk is maximal by 5 min of
NGF
treatment, persists for approximately 1 hr, and subsequently declines by 18 hr. Treatment with either basic fibroblast growth factor, epidermal growth factor, or orthovanadate also leads to association of ERK1 with gp140prototrk without tyrosine phosphorylation of the latter. The interaction between ERK1 and gp140prototrk may prove relevant to the
NGF
mechanism.
...
PMID:NGF and other growth factors induce an association between ERK1 and the NGF receptor, gp140prototrk. 146 7
The prostatic growth factors require a membrane specific receptor to which they must bind in order to carry out their biological activities correctly. The aim of this study was to isolate and quantify the epidermal growth factor receptor in prostatic tissue and indirectly determine the growth factors acting on it (EGF, TGF alpha, PDGF,
NGF
, IGF). From September, 1992 to June, 1993, we studied 55 patients. These were divided into two groups: the first group comprised 49 patients with benign prostatic hyperplasia (BPH) and 6 patients with prostatic carcinoma comprised the second group. Samples of the prostate were obtained following suprapubic (12 cases), TUR (38 cases), radical prostatectomy (1 case) and transrectal biopsy (4 cases). The
EGFR
was determined by radioimmunoassay (
EGFR
-RIA, Vienna Lab, Labordiagnostica GmbH). For the overall group of patients, we obtained mean
EGFR
values of 6.36 +/- 0.59 fmol/mg of protein and a positivity of 96.36% and 100% for BPH and malignant proliferative processes, respectively. The foregoing data show that
EGFR
was isolated from the tissue we analyzed and has an evident role in the regulation of prostate growth.
...
PMID:[Involvement of epidermal growth factor receptor (EGFR) in the etiopathogenesis of prostatic proliferative processes]. 752 95
Deletion of a conserved juxtamembrane sequence (KFG) in the Trk NGF receptor resulted in impaired neurite outgrowth, somatic hypertrophy, and induction of c-fos, c-jun, and TIS1 immediate-early genes. In contrast, these receptors retained the ability to mediate
NGF
-promoted survival and TIS8 and TIS11 immediate-early gene induction. The mutated receptor also mediated unimpaired autophosphorylation; SHC, PLC-gamma 1, and
ERK
tyrosine phosphorylation; and PI-3 kinase and
ERK
activation. However, SNT protein tyrosine phosphorylation, which wild-type receptors mediate via a ras-independent pathway, was undetectable. These findings indicate that the KFG sequence is indispensable for activating a ras-independent
NGF
signaling pathway involved in promoting neuronal differentiation and highlight potential roles of non-tyrosine-containing receptor domains in growth factor signal transduction.
...
PMID:Deletion of a conserved juxtamembrane sequence in Trk abolishes NGF-promoted neuritogenesis. 764 92
The purpose of this study was to examine
ERK
enzymatic activity after neuronal differentiation and to determine if the intracellular enzyme continues to be responsive to changes in extracellular
NGF
. The results demonstrate that long-term
NGF
maintains
ERK
activity above normal resting levels, but that it is also greatly reduced from that achieved rapidly after
NGF
stimulation. Withdrawal of
NGF
reduces
ERK
activity further. Re-stimulation of the enzyme by readdition of
NGF
after
NGF
withdrawal results in a 10-fold increase in activity. Withdrawal and readdition of EGF is without such a marked effect. The ability of
ERK
to respond to changes in
NGF
after neuronal differentiation indicates that this enzyme may serve important functions in addition to the induction of the neuronal phenotype.
...
PMID:Differential effect of NGF and EGF on ERK in neuronally differentiated PC12 cells. 786 52
The insulin receptor-related receptor (IRR) has recently been identified as a member of the insulin receptor tyrosine kinase family; however, its endogenous ligand and biological function are still unknown. In contrast to the very widespread pattern of expression of the homologous insulin and IGF-I receptors, IRR demonstrates a very restricted cellular distribution. Using in situ hybridization and immunohistochemistry, we now show that the expression of this receptor is selectively concentrated in a subset of neurons where its appearance is closely associated with that of the NGF receptor
TRK
. IRR and
TRK
demonstrate synchronized patterns of coexpression in neural crest-derived sensory and sympathetic neurons and in non-neural crest basal forebrain and striatal neurons. Both appear early in the embryonic development of dorsal root and trigeminal neurons and somewhat later, near the time of birth, in sympathetic neurons. Expression of both IRR and
TRK
appears perinatally in basal forebrain neurons, reaching maximal levels about postnatal day 20. This association is highly selective, since
TRK
mRNA is not detected anywhere in the developing nervous system in the absence of coordinate IRR expression, and the same is true for IRR expression with respect to
TRK
. In the adult rat, the majority of
TRK
-positive sensory neurons still express IRR mRNA, and coexpression in sympathetic and forebrain neurons continues without evidence of diminution. These findings are consistent with a functional linkage of the IRR and
TRK
receptors in
NGF
-sensitive neurons.
...
PMID:Selective coexpression of insulin receptor-related receptor (IRR) and TRK in NGF-sensitive neurons. 804 42
Proto-
TRK
and proto-
RET
genes encode receptor type tyrosine kinases. Oncogenic rearrangements of both proto-oncogenes have been detected with a significant frequency in human papillary thyroid carcinomas. Chimeric Ret and Trk oncoproteins, encoded by different rearrangements of proto-
TRK
and proto-
RET
genes, display a constitutive phosphorylation on tyrosine. Moreover, it has been shown that phosphorylated tyrosine receptors, activated by their ligands, form multiprotein complexes responsible for transducing mitogenic or differentiation signals. We have therefore begun to analyse in this study the signal transduction pathways triggered by different Ret and Trk oncoproteins. We have shown that the SH2 domain of the adaptor protein Shc coimmunoprecipitates with all the Ret and Trk oncoproteins as well as with
NGF
-activated proto-Trk receptor. Tyrosine phosphorylation of Trk proteins both normal and oncogenic is necessary for their binding to Shc. In addition, in cells containing either Ret or Trk oncoproteins, Shc proteins are constitutively phosphorylated on tyrosine and bound to Grb2. Only in in vitro experiments were Ret and Trk oncoproteins shown to bind the SH2 region of Grb2. Finally, when proto-Trk product is stimulated by
NGF
, Shc phosphorylation and association with Grb2 are induced. In conclusion, we have shown that Ret and Trk oncoproteins can form multiprotein complexes, however, the functional meaning of the described interactions has to be elucidated.
...
PMID:The oncogenic versions of the Ret and Trk tyrosine kinases bind Shc and Grb2 adaptor proteins. 818 61
The expression and cellular localization of
NGF
receptors in the developing rat retina were investigated immunocytochemically and biochemically. In in vitro preparations of retinal neurons from neonatal rats the functional NGF receptor p140trkA was immunocytochemically detected on retrogradely labeled retinal ganglion cells (RGCs). In transverse retinal sections p140trk-immunopositive cells were localized exclusively at the level of the RGC layer. Affinity labeling with 125I-
NGF
, chemical cross-linking, and immunoprecipitation with anti-
NGF
antibodies revealed the presence of three complexes which migrate on SDS-PAGE at approximately 90, 95, and 150 kDa. The bands at 90 and 95 kDa correspond to the so-called low affinity NGF receptor p75NGFR. Western blotting experiments using anti-
TRK
antibodies revealed that the slowest migrating band (150 kDa), which is not immunoprecipitated by monoclonal antibodies to p75NGFR, corresponds to p140trkA. The presence of the functional NGF receptor on RGCs provides the molecular explanation for the reported sensitivity of these cells to the biological action of
NGF
.
...
PMID:Developing rat retinal ganglion cells express the functional NGF receptor p140trkA. 836 54
We previously showed that the proto-oncogene
RON
encodes the tyrosine kinase receptor for Macrophage Stimulating Protein (MSP), originally isolated as a chemotactic factor for peritoneal macrophages. To elucidate the biological role of MSP we studied the expression of the Ron receptor in vivo, and the response to the factor in vitro.
RON
specific transcripts were detectable in mouse liver from early embryonal life (day 12.5 p.c.) through adult life. Adrenal gland, spinal ganglia, skin, lung and--unexpectedly--ossification centers of developing mandible, clavicle and ribs were also positive at later stages (day 13.5-16.5 p.c.). From day 17.5
RON
was expressed in the gut epithelium and in a specific area of the central nervous system, corresponding to the nucleus of the hypoglossus. In adult mouse tissues
RON
transcripts were observed in brain, adrenal glands, gastro-intestinal tract, testis and kidney. Epithelial, osteoclast-like and neuroendocrine cells express the Ron receptor and respond to MSP in vitro. In the neuroendocrine PC12 cell line, while
NGF
induced growth arrest and morphological differentiation, MSP behaved as a strong mitogen. These findings show that the Ron receptor and its ligand are involved in the development of epithelial tissues, bones, and neuroendocrine derivatives driving cells towards the proliferation program.
...
PMID:The proto-oncogene RON is involved in development of epithelial, bone and neuro-endocrine tissues. 854 20
There is considerable interest in the role of the
TRK
family of neurotrophin receptors in regulating the survival, growth and differentiation of normal and neoplastic nerve cells. Indeed, there is increasing evidence that
TRK
genes play an important role in the biology and clinical behavior of neuroblastomas, tumors of the peripheral nervous system. Evidence from several independent studies suggests that high expression of TrkA is an indicator of favorable outcome, and there is an inverse correlation between TrkA expression and N-myc amplification. In addition, some primary neuroblastomas differentiate in vitro in the presence of
NGF
but die in its absence. We have evidence that coexpression of full-length TrkB and BDNF is associated with N-myc amplification and may represent an autocrine survival pathway. Conversely, truncated TrkB is expressed predominantly in differentiated tumors. Finally, Trk-C is expressed in favorable neuroblastomas, essentially all of which also express TrkA. In summary, the study of neurotrophin receptor expression and function in neuroblastomas may provide important insights into the role that these pathways play in the pathogenesis and clinical behavior of this tumor. Ultimately, these pathways may provide attractive targets for the development of therapy aimed at inducing differentiation or programmed cell death in these tumors.
...
PMID:Expression of TrkA, TrkB and TrkC in human neuroblastomas. 904 30
Picomolar concentrations of purified amyloid precursor protein (APP) potentiate the neurotrophic activity of suboptimal concentrations of
NGF
on PC12 cells. To understand the molecular basis for this potentiation, we have characterized the signal transduction pathway used by APP for its neurotrophic activity. APP stimulated the tyrosine phosphorylation of a number of proteins including insulin receptor substrate-1 (IRS-1). Incubation of naive cells with antisense oligonucleotides to IRS-1 mRNA resulted in a dramatic reduction of IRS-1 levels and inhibition of APP stimulated neurite outgrowth. Phosphotidylinositol 3-kinase became associated with IRS-1 and activated upon APP stimulation. Extracellular signal-regulated kinase (
ERK
1 and
ERK
2) phosphorylation was detected by both immunoblot analysis and immunocytochemistry using antibodies directed to their phosphorylated (and hence, activated) form. There was also an elevation of
ERK
kinase activity. The potentiation of
NGF
activity was reflected in a correspondingly synergistic elevation of tyrosine phosphorylated
ERK
. The pattern of signal transduction targets indicates that APP potentiated the neurotrophic effects of
NGF
via the activation of the IRS-1 signaling pathway.
...
PMID:Amyloid precursor protein requires the insulin signaling pathway for neurotrophic activity. 949 42
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