Gene/Protein Disease Symptom Drug Enzyme Compound
Pivot Concepts:   Target Concepts:
Query: EC:2.7.11.1 (protein kinase)
 81,284 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Defects in the c-ret proto-oncogene, a member of the protein tyrosine kinase receptor family, have recently been linked to two types of genetic syndromes, Hirschsprung's disease and the multiple endocrine neoplasia family of inherited cancers. RET/ptc2 is the product of a papillary thyroid carcinoma translocation event between the genes coding for c-ret and the type I alpha regulatory subunit of protein kinase A (RI alpha) (Lanzi, C., Borrello, M., Bongarzone, I., Migliazza, A., Fusco, A., Grieco, M., Santoro, M., Gambetta, R., Zunino, F., Della Porta, G., and Pierotti, M. (1992) Oncogene 7, 2189-2194). The resulting 596-residue protein contains the first two-thirds of RI alpha and the entire tyrosine kinase domain of c-ret (RETtk). An in vivo assay of growth stimulatory effects was developed, which consisted of microinjecting a RET/ptc2 expression plasmid into the nuclei of 10T1/2 mouse fibroblasts and observing the incorporation of 5-bromodeoxyuridine. This assay was used to determine that only the dimerization domain of RI alpha fused to RETtk is required for RET/ptc2's mitogenic activity. In addition, all of the reported Hirschsprung's disease point mutations in the RETtk (S289P, R421Q, and R496G) inactivate RET/ptc2 in our assay, confirming that these are loss of function mutations. Two tyrosines outside the conserved kinase core were also identified that are essential for full mitogenic activity of RET/ptc2. These two tyrosines, Tyr-350 and Tyr-586, are potential sites for Src homology 2 and phosphotyrosine binding domain interactions.
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PMID:Tyrosines outside the kinase core and dimerization are required for the mitogenic activity of RET/ptc2. 755 72

1. The aim of this study was a pharmacological characterization of the multiple NANC inhibitory transmission systems producing relaxation of the circular muscle of guinea-pig proximal colon. In the presence of atropine (1 microM), guanethidine (3 microM) and of the tachykinin NK1 and NK2 receptor antagonists, SR 140333 (0.3 microM) and MEN 10627 (1 microM), respectively, electrical field stimulation (EFS) produced a frequency-dependent (0.1-3 Hz) relaxation. During a cumulative frequency-response curve, the maximal relaxant effect was produced at 3 Hz and approached the maximal relaxation to 1 microM isoprenaline. In the presence of both apamin (0.3 microM) and L-nitroarginine (L-NOARG, 100 microM), EFS failed to evoke relaxation up to 1 Hz; at 1-10 Hz, a slowly developing relaxation ensured which approached 50% of the Emax to isoprenaline. The EFS-evoked NANC relaxation, either in the presence or absence of apamin and L-NOARG, was unaffected by in vitro capsaicin pretreatment (10 microM for 15 min). 2. Three protocols of EFS were developed for further pharmacological analysis: (a) EFS at 1 Hz for 5 s in the presence of L-NOARG, producing a transient fast apamin-sensitive relaxation; (b) EFS at 1 Hz for 5 s in the presence of apamin, producing a transient fast L-NOARG-sensitive relaxation; and (c) EFS at 10 Hz for 5 s in the presence of both apamin and L-NOARG, producing a transient but slowly developing and more sustained relaxation. 3. The neutral endopeptidase inhibitor, thiorphan (1-10 microM), enhanced and prolonged the apamin- and L-NOARG-resistant NANC relaxation produced by EFS at 10 Hz, without affecting that evoked at 1 Hz in the presence of apamin or L-NOARG. The angiotensin converting enzyme inhibitor, captopril (1-10 microM) was without effect. 4. The cAMP analogue inhibitor of protein kinase A, Rp-cAMPs (100-300 microM) significantly reduced and shortened the NANC relaxation produced by 10 Hz EFS in the presence of L-NOARG without affecting that produced by 1 Hz EFS in the presence of apamin or L-NOARG. 5. The inhibitor of sarcoplasmic reticulum Ca-ATPase, cyclopiazonic acid (CPA, 3-10 microM for 60 min) abolished the 1 Hz EFS-induced relaxation in the presence of L-NOARG, and greatly inhibited that produced by 10 Hz EFS in the presence of both apamin and L-NOARG. The relaxation produced by 1 Hz EFS in the presence of apamin was inhibited by about 32% at 10 microM only. 6. Nifedipine (1 microM) did not affect the EFS-induced NANC relaxations. In the presence of nifedipine, tetraethylammonium (TEA, 1 mM) enhanced the 1 Hz EFS-induced relaxation in the presence of L-NOARG (158% of control) and that produced by 10 Hz EFS in the presence of apamin and L-NOARG (215% of control) while that evoked by 1 Hz EFS in the presence of apamin was slightly affected (109% of control). 7. In the presence of atropine, guanethidine, SR 140333 and MEN 10627, bath application of human vasoactive intestinal polypeptide (VIP, 0.1 nM-10 nM) produced a concentration-dependent, slowly developing relaxation of colonic strips. The relaxation to VIP was unaffected by apamin (0.3 microM), L-NOARG (100 microM), nifedipine (1 microM) or nifedipine plus TEA (1 mM); it was inhibited by CPA (10 microM) and Rp-cAMPs (100 microM) and was potentiated by thiorphan (10 microM). 8. The putative VIP receptor antagonist, VIP(10-28) (10 microM) did not affect the VIP-induced relaxation nor the NANC relaxation to 10 Hz EFS in the presence of apamin and L-NOARG. 9. The present findings provide evidence that three distinct NANC inhibitory mechanisms mediate relaxation of the circular muscle of the guinea-pig proximal colon. The first system provides a fast relaxation in response to low frequency of stimulation and may involve the action of a transmitter(s) (possibly ATP) which mobilizes intracellular Ca2+ from sarcoplasmic reticulum leading to the activation of apamin-sensitive K+ channels. The second system likewise provides a fast relaxation of the colon in
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PMID:Characterization of the apamin- and L-nitroarginine-resistant NANC inhibitory transmission to the circular muscle of guinea-pig colon. 888 60

Multiple endocrine neoplasia type 1 (MEN1) is tightly linked to the muscle-type glycogen phosphorylase (PYGM) gene in 11q13. This region of the human genome contains additional disease-related loci implicated in the development of insulin-dependent diabetes mellitus, familial paraganglioma type 2, spinocerebellar ataxia type 5, Bardet-Biedl syndrome and translocation t(11;17) described in B-cell non-Hodgkin's lymphoma. We approached cloning of candidate disease genes from 11q13 by large-scale genomic sequencing. We obtained > 106 kb of sequence around the PYGM gene and established a transcriptional map that includes: (i) two genes previously localized to 11q13, PYGM and a zinc-finger protein (ZFM1) gene; (ii) the germinal center kinase (GCK, human B-lymphocyte serine/threonine protein kinase) gene; (iii) a novel human CDC25-like (HCDC25L) gene; (iv) a dystrophia myotonica protein kinase-like (DMPKL) gene; and (v) a novel ubiquitously expressed gene of unknown function (germinal center kinase- neighboring gene, GCKNG).
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PMID:The germinal center kinase gene and a novel CDC25-like gene are located in the vicinity of the PYGM gene on 11q13. 934 81

Recent advances in the molecular biology has served to unveil the underlying genetic and epigenetic alterations in pituitary adenomas. Three nuclear transcriptional factors, AP-1, CREB, and Pit-1, which are targets of protein kinase C and A, appear to play critical roles in both neoplastic growth and hormone secretion in hormone-producing adenomas. The alteration of G proteins such as Gs and Gi2 is a direct cause of the activation of such transcriptional factors. Autocrine growth factor/cytokine loops also contribute to the augmented signal transductions. Bromocriptine and somatostatin analogs have effects to lower cellular cAMP level through inhibitory G proteins, although the mechanism leading to cellular apoptosis is unknown. On the other hand, most non-functioning adenomas may not have PKC- or PKA-mediated oncogenic mechanisms. Although the loss of Rb and p27Kip1 genes has been demonstrated as a cause of murine pituitary adenomas, the role of tumor suppressor genes for human pituitary adenomas remains elusive. However, potential candidates for the suppressor genes are now emerging. The recently cloned multiple endocrine neoplasia type I gene is one example. Alterations of c-myc/bcl-2, and ras, although rare, appear to be an important cause of the process by which adenoma cells acquire aggressive phenotypes. Further studies on the links between abnormal signal transductions and aberrant tumor suppressor genes will be needed to clarify the whole picture of pituitary oncogenesis.
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PMID:Molecular basis of pituitary oncogenesis. 1072 13

The presence of two families of seven distinct mammalian cyclin-dependent kinase (CDK) inhibitor genes is thought to mediate the complexity of connecting a variety of cellular processes to the cell cycle control pathway. The distinct pattern of tissue expression of CDK inhibitor genes suggests that they may function as tumor suppressors with different tissue specificities. To test this hypothesis, we have characterized two strains of double mutant mice lacking either p18(INK4c) and p27(KIP1) or p18(INK4c) and p21(CIP1/WAF1). Loss of both p18 and p27 function resulted in the spontaneous development by 3 months of age of at least eight different types of hyperplastic tissues and/or tumors in the pituitary, adrenals, thyroid, parathyroid, testes, pancreas, duodenum, and stomach. Six of these hyperplastic tissues and tumors were in endocrine organs, and several types of tumors routinely developed within the same animal, a phenotype reminiscent of that seen in combined human multiple endocrine neoplasia syndromes. The p18-p21 double null mice, on the other hand, developed pituitary adenomas, multifocal gastric neuroendocrine hyperplasia, and lung bronchioalveolar tumors later in life. G(1) CDK2 and CDK4 kinase activities were increased in both normal and neoplastic tissues derived from mice lacking individual CDK inhibitors and were synergistically stimulated by the simultaneous loss of two CDK inhibitors. This indicates that an increase in G(1) CDK kinase activity is a critical step during but is not sufficient for tumor growth. Our results suggest that functional collaborations between distinct CDK inhibitor genes are tissue specific and confer yet another level of regulation in cell growth control and tumor suppression.
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PMID:Functional collaboration between different cyclin-dependent kinase inhibitors suppresses tumor growth with distinct tissue specificity. 1091 96

Exit from mitosis requires the inactivation of cyclin-dependent kinase (CDK) activity. In the budding yeast Saccharomyces cerevisiae, a number of gene products have been identified as components of the signal transduction network regulating inactivation of CDK (called the MEN, for the mitotic exit network). Cdc15, one of such components of the MEN, is an essential protein kinase. By the two-hybrid screening, we identified Cdc15 as a binding protein of Tem1 GTPase, another essential regulator of the MEN. Coprecipitation experiments revealed that Tem1 binds to Cdc15 in vivo. By deletion analysis, we found that the Tem1-binding domain resides near the conserved kinase domain of Cdc15. The cdc15-LF mutation, which was introduced into the Tem1-binding domain, reduced the interaction with Cdc15 and Tem1 and caused temperature-sensitive growth. The kinase activity of Cdc15 was not so much affected by the cdc15-LF mutation. However, Cdc15-LF failed to localize to the SPB at the restrictive temperature. Our data show that the interaction with Tem1 is important for the function of Cdc15 and that Cdc15 and Tem1 function in a complex to direct the exit from mitosis.
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PMID:A novel functional domain of Cdc15 kinase is required for its interaction with Tem1 GTPase in Saccharomyces cerevisiae. 1129 Jul 2

The paper reviews the data on the molecular structure of the protooncogene RET encoding for receptor-type protein kinase, on the mechanism of transformation of the normal protooncogene RET to a dominant transforming oncogene, and on RET mutations detected in patients with the MEN-2 syndrome. Moreover, it presents the authors' own findings. The familial medullary thyroid carcinoma burdened genealogy shows a new point mutation TCG(Ser)-->GCG(Ala) in codon 891, in the exon 15 of the protooncogene RET. This mutation was not detected in the chromosomes of healthy individuals. Analyzing the linkage with two known and two new polymorphic markers showed that there was a cisaggregation of informative polymorphic markers, phenotypic manifestation of the disease, and mutations in the genealogy in question. In the protooncogene RET, there were two new polymorphisms: G/A at position 24 in intron 14 and C/T in codon 836 (exon 14). The rate of the polymorphism encountered in codon 836 proved to be similar for the Russians and the Germans (0.96%), which was also seen for two earlier described polymorphisms in codon 691 (0.80 and 0.81, respectively) and in codon 904 (0.21 and 0.22). At the same time, there were statistically significant differences in the rates of intron 14 polymorphism (0.87 and 0.77, respectively). In a family having MEN 2, a proband displayed TGC-->CGC mutation in codon 634 of the gene RET in the heterozygous state. The mutation results in substitution of cysteine amino acid residue in the cysteine-rich extracellular domain of protein kinase encoded by the gene RET for arginine. The results of molecular analysis were used to confirm its clinical diagnosis and to indicate that effective care should be delivered in MEN 2a.
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PMID:[Molecular diagnosis of multiple type 2 endocrine neoplasia]. 1133 5

SNT/FRS2 is a lipid anchored docking protein that contains an amino-terminal myristylation signal, followed by a phosphotyrosine-binding (PTB) domain and a carboxy-terminal region with multiple tyrosine residues. Here we show that the SNT/FRS2 PTB domain binds to RET receptor tyrosine kinase activated by glial cell line-derived neurotrophic factor (GDNF) or multiple endocrine neoplasia (MEN) 2 mutations. Analyses by site directed-mutagenesis revealed that it binds to tyrosine 1062 in RET that is also known to be a binding site for the SHC adaptor protein. Whereas SHC bound to RET was associated with GRB2 and GAB1 proteins, SNT/FRS2 was associated with GRB2 only, suggesting that SNT/FRS2 is involved mainly in the activation of the RAS/mitogen activated protein kinase (MAPK) pathway but not the phosphatidylinositol 3-kinase (PI3-K)/AKT pathway. In addition, phosphorylated SNT/FRS2 appeared to directly complex with SHP-2 tyrosine phosphatase. These results suggest that tyrosine 1062 in RET provides a site for the interaction of multiple signaling molecules and that the balance of SHC and SNT/FRS2 binding may affect the nature of the intracellular signaling for cell proliferation, differentiation and survival induced by activated RET.
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PMID:Identification of SNT/FRS2 docking site on RET receptor tyrosine kinase and its role for signal transduction. 1136 Jan 77

The list of multiple endocrine neoplasias (MENs) that have been molecularly elucidated is growing with the most recent addition of Carney complex. MEN type 1 (MEN 1), which affects primarily the pituitary, pancreas, and parathyroid glands, is caused by mutations in the menin gene. MEN type 2 (MEN 2) syndromes, MEN 2A and MEN 2B that affect mainly the thyroid and parathyroid glands and the adrenal medulla, and familial medullary thyroid carcinoma (FMTC), are caused by mutations in the REToncogene. Finally, Carney complex, which affects the adrenal cortex, the pituitary and thyroid glands, and the gonads, is caused by mutations in the gene that codes for regulatory subunit type 1A of protein kinase A (PKA) (PRKAR1A) in at least half of the known patients. Molecular defects have also been identified in syndromes related to the MENs, like Peutz-Jeghers syndrome (PJS) (the STK11/LKB1 gene), and Cowden (CD; the PTEN gene) and von Hippel-Lindau disease (VHLD; the VHL gene). Although recognition of these syndromes at a young age generally improves prognosis, the need for molecular testing in the diagnostic evaluation of the MENs is less clear. This review presents the newest information on the clinical and molecular genetics of the MENs (MEN 1, MEN 2, and Carney complex), including recommendations for genetic screening, and discusses briefly the related syndromes PJS, CD and VHLD.
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PMID:Clinical genetics of multiple endocrine neoplasias, Carney complex and related syndromes. 1140 58

Carney complex is a multiple neoplasia syndrome featuring cardiac, endocrine, cutaneous, and neural tumors, as well as a variety of pigmented lesions of the skin and mucosae. Carney complex is inherited as an autosomal dominant trait and may simultaneously involve multiple endocrine glands, as in the classic multiple endocrine neoplasia syndromes 1 and 2. Carney complex also has some similarities to McCuneAlbright syndrome, a sporadic condition that is also characterized by multiple endocrine and nonendocrine tumors. Carney complex shares skin abnormalities and some nonendocrine tumors with the lentiginoses and certain of the hamartomatoses, particularly Peutz-Jeghers syndrome, with which it shares mucosal lentiginosis and an unusual gonadal tumor, large-cell calcifying Sertoli cell tumor. Careful clinical analysis has enabled positional cloning efforts to identify two chromosomal loci harboring potential candidate genes for Carney complex. Most recently, at the 17q22-24 locus, the tumor suppressor gene PRKAR1A, coding for the type 1alpha regulatory subunit of PKA, was found to be mutated in approximately half of the known Carney complex kindreds. PRKAR1A acts a classic tumor suppressor gene as demonstrated by loss of heterozygosity at the 17q22-24 locus in tumors associated with the complex. The second locus, at chromosome 2p16, to which most (but not all) of the remaining kindreds map, is also involved in the molecular pathogenesis of Carney complex tumors, as demonstrated by multiple genetic changes at this locus, including loss of heterozygosity and copy number gain. Despite the known genetic heterogeneity in the disease, clinical analysis has not detected any corresponding phenotypic differences between patients with PRKAR1A mutations and those without. This article summarizes the clinical manifestations of Carney complex from a worldwide collection of affected patients and also presents revised diagnostic criteria for Carney complex. In light of the recent identification of mutations in the PRKAR1A gene, an estimate of penetrance and recommendations for genetic screening are provided.
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PMID:Clinical and molecular features of the Carney complex: diagnostic criteria and recommendations for patient evaluation. 1154 23


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