Gene/Protein Disease Symptom Drug Enzyme Compound
Pivot Concepts:   Target Concepts:
Query: UNIPROT:P06889 (Mol)
 630,302 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Due to their selectivity towards voltage-sensitive calcium channels (VSCCs) omega-conotoxins are being exploited as a new class of therapeutics in pain management and may also have potential application in ischaemic brain injury. Here, the structure-activity relationships (SARs) of several omega-conotoxins including GVIA, MVIIA, CVID and MVIIC are explored. In addition, the three-dimensional structures of these omega-conotoxins and some structurally related peptides that form the cysteine knot are compared, and the effects of the solution environment on structure discussed. The diversity of binding and functional assays used to measure omega-conotoxin potencies at the N-type VSCC warranted a re-evaluation of the relationship between these assays. With one exception, [A22]-GVIA, this analysis revealed a linear correlation between functional (peripheral N-type VSCCs) and radioligand binding assays (central N-type VSCCs) for the omega-conotoxins and analogues that were tested over three studies. The binding and functional results of several studies are compared in an attempt to identify and distinguish those residues that are important in omega-conotoxin function as opposed to those that form part of the structural scaffold. Further to determining what omega-conotoxin residues are important for VSCC binding, the range of possible interactions between the ligand and channel are considered and the factors that influence the selectivity of MVIIA, GVIA and CVID towards N-type VSCCs examined.
J Mol Recognit
PMID:Structure-activity relationships of omega-conotoxins at N-type voltage-sensitive calcium channels. 1082 50

A genetic screen using mice was performed to identify dominant loci affecting behavior. Mice were mutagenized with ENU, then bred to examine their G1 offspring for behavioral abnormalities. Potentially mutant G1 pups were screened through a variety of behavioral assays, including tests of learning and memory, sensorimotor gating, fear and anxiety, nociception (pain perception) and locomotor activity. Mice falling outside the normal performance distribution in these tests were considered potential behavioral mutants and were bred for further analysis. Outliers included both animals with very discrete defects and animals with abnormal performance across a range of tests. To date, we have identified two confirmed mutants affecting sensorimotor gating. These results provide further impetus for the use of random mutagenesis screens as a tool for dissecting the genetic basis of brain and behavior.
Mol Psychiatry 2000 Jul
PMID:A genetic screen for novel behavioral mutations in mice. 1088 47

The Drosophila single-minded (sim) transcription factor, is a master regulator of fruitfly neurogenesis. Recently, we have cloned and mapped a human homolog of sim, SIM2, to chromosome 21 in the so-called 'Down syndrome chromosomal region'. Three copies of SIM2 may contribute to some Down syndrome (DS) phenotypes because of the mapping position function as transcriptional repressor, temporal and spatial expression pattern of mouse Sim2, and the potentially analogous role of human SIM2 to that of Drosophila sim during neurogenesis. In order to validate this hypothesis in vivo, we have created the first bacterial artificial chromosome transgenic mice overexpressing a gene possibly involved in DS with only one or two additional copies of mouse Sim2. The transgene was shown to be expressed in the same spatial pattern as the endogenous gene. The mice develop normally, are fertile and do not show detectable histopathological abnormalities. However, detailed analysis of their behavior revealed anxiety-related/reduced exploratory behaviour and sensitivity to pain, phenotypes similar to those also present in other partial trisomy 16 mouse models of DS. Our data therefore suggest that overexpression of SIM2 contributes to some of the complex DS phenotypes.
Hum Mol Genet 2000 Jul 22
PMID:Mice trisomic for a bacterial artificial chromosome with the single-minded 2 gene (Sim2) show phenotypes similar to some of those present in the partial trisomy 16 mouse models of Down syndrome. 1091 74

We characterized anticancer effects of opioid analgesics that are clinically used for cancer patients for pain relief. Treatment with 100 microM buprenorphine, a representative analgesic, induced cell death of human carcinomas, such as A549 (squamous epithelial cell of lung cancer), MCF-7 (breast cancer) and N417 (small cell of lung cancer), but not in KATO III (gastric cancer) cells as evaluated by alamar blue assay. Among 18 clinically utilized and related analgesics, buprenorphine and loperamide showed potent inhibition of cell viability. However, these anti-cancer effects were not affected by opioid receptor antagonists nor by pertussis toxin. Buprenorphine-induced cell death occurred as early as 1 h after the addition, and its T1/2 of cell viability inhibition was 3 h. The cell death manifested the characteristics of apoptosis, such as DNA-laddering and nuclear fragmentation, which were sensitive to a caspase inhibitor, Z-Asp-CH2-DCB. The nuclear fragmentation was independent of cell cycle phase specificity. The activity of caspase-3-like protease which is known to be closely related to apoptotic DNA laddering was markedly enhanced by buprenorphine. However, the inhibition of cell viability by buprenorphine was not affected by the caspase inhibitor. These findings suggest that some opioid analgesics induce typical apoptotic features sensitive to the caspase inhibitor, while also inhibition of cell viability insensitive to the inhibitor.
Int J Mol Med 2000 Sep
PMID:Opioid analgesic-induced apoptosis and caspase-independent cell death in human lung carcinoma A549 cells. 1093 99

The highly potent vanilloid receptor (VR) agonist resiniferatoxin has been radiolabeled with 125I, and the pharmacology to the cloned rodent VR, VR1, and the endogenous VR in rat spinal cord membranes has been characterized. [125I]RTX binding to human embryonic kidney 293 cells expressing VR1 was reversible and with high affinity (Kd = 4.3 nM) in an apparent monophasic manner. In rat spinal cord membranes, [125I]RTX bound with a similar high affinity (Kd = 4.2 nM) to a limited number of binding sites (Bmax = 51 +/- 8 fmol/mg of protein). The pharmacology of recombinant rodent VR1 and the endogenous rat VR1 was indistinguishable when measuring displacement of [125I]RTX binding (i.e., the following rank order of affinity was observed: RTX > I-RTX > olvanil > capsaicin > capsazepine). Capsaicin and RTX induced large nondesensitizing currents in Xenopus laevis oocytes expressing VR1 (EC50 values were 1300 nM and 0.2 nM, respectively), whereas I-RTX induced no current per se at concentrations up to 10 microM. However, I-RTX completely blocked capsaicin-induced currents (IC50 = 3.9 nM). In vivo, I-RTX effectively blocked the pain responses elicited by capsaicin (ED50 = 16 ng/mouse, intrathecally). The present study showed that I-RTX is at least 40-fold more potent than the previously known VR antagonist, capsazepine. Thus, I-RTX as well as its radiolabeled form, should be highly useful for further exploring the physiological roles of VRs in the brain and periphery.
Mol Pharmacol 2001 Jan
PMID:Iodo-resiniferatoxin, a new potent vanilloid receptor antagonist. 1112 18

The mu-opioid receptor (MOR1) mediates the main analgesic effects of morphine and several other opioids. However, the clinical benefit of these drugs is limited by the development of tolerance and dependence. In vitro the mu-opioid receptor undergoes a rapid homologous desensitization during prolonged agonist exposure. We have recently identified the serine residues, Ser(261) and Ser(266), within the third intracellular loop as two consensus calcium/calmodulin-dependent protein kinase II (CaMKII) sites required for agonist-induced phosphorylation and desensitization of the mu-opioid receptor in HEK 293 cells. Since the specific pattern of mu-opioid receptor regulation in vivo is thought to depend on the cell- and tissue-specific complement of protein kinases, we examined the spatial relation between MOR1 and CaMKII in rat brain using specific antibodies. We found that MOR1 and CaMKII alpha which is a major CaMKII isoform expressed in the central nervous system co-exist in distinct pain-processing brain regions including the superficial layers of the spinal cord dorsal horn and dorsal root ganglia. At high power magnification it was evident that virtually all MOR1-expressing nociceptive spinal cord neurons also co-contain CaMKII. In naive or saline-treated animals the mu-opioid receptor was almost exclusively confined to the plasma membrane, while CaMKII was localized to vesicle-like structures throughout the cytoplasm. After subcutaneous administration of the mu-opioid receptor agonist, etorphine, a large proportion of the mu-opioid receptor proteins redistributed from the plasma membrane into the cytosol where it was frequently co-localized with CaMKII. Together, we identify CaMKII as a potential protein kinase, which by virtue of its colocalization with MOR1 may be in a position to phosphorylate the mu-opioid receptor and may thus contribute to the development of tolerance to opioid analgesics.
Brain Res Mol Brain Res 2000 Dec 28
PMID:Colocalization of the mu-opioid receptor and calcium/calmodulin-dependent kinase II in distinct pain-processing brain regions. 1114 27

Human TRKA (NTRK1) encodes the receptor tyrosine kinases (RTKs) for nerve growth factor (NGF) and is the gene responsible for congenital insensitivity to pain with anhidrosis (CIPA), an autosomal recessive disorder characterized by a lack of pain sensation and anhidrosis. We reported 11 putative missense mutations in 31 CIPA families from various ethnic groups. Here we have introduced the corresponding mutations into the TRKA cDNA and examined NGF-stimulated autophosphorylation. We find that wild-type TRKA precursor proteins in a neuronal and a non-neuronal cell line were differentially processed and phosphorylated in an NGF-dependent and -independent manner, respectively. Two mutants (L93P and L213P) in the extracellular domain were aberrantly processed and showed diminished autophosphorylation in neuronal cells. Five mutants (G516R, G571R, R643W, R648C and G708S) in the tyrosine kinase domain were processed as wild-type TRKA but showed significantly diminished autophosphorylation in both neuronal and non-neuronal cells. In contrast, R85S and (H598Y; G607V), detected previously as double and triple mutations, are probably polymorphisms in a particular ethnic background. The other putative mutant D668Y might be a rare polymorphism or might impair the function of TRKA without compromising autophosphorylation. Mutated residues in the tyrosine kinase domain are conserved in various RTKs and probably contribute to critical function of these proteins. Thus, naturally occurring TRKA missense mutations with loss of function provide considerable insight into the structure-function relationship in the RTK family. Our data may aid in developing a drug which targets the clinically devastating 'complex regional pain syndrome'.
Hum Mol Genet 2001 Feb 01
PMID:Congenital insensitivity to pain with anhidrosis (CIPA): effect of TRKA (NTRK1) missense mutations on autophosphorylation of the receptor tyrosine kinase for nerve growth factor. 1115 35

Endometriotic lesions secrete chemokines that recruit immune cells into the peritoneal cavity. The accumulation of these immune cells, especially activated macrophages and T lymphocytes, is thought to mediate inflammatory symptoms associated with endometriosis. Previous studies have demonstrated that RANTES (regulated on activation, normal T cell expressed and secreted) is synthesized by endometriotic stromal cells and circulates in peritoneal fluid, commensurate with the stage of endometriosis. In the current studies, we used the human monocytic cell line, U937, to assay chemotactic activity in cell culture conditioned media and peritoneal fluid from patients with endometriosis and normal controls. We demonstrated expression of the human RANTES receptors CCR-1 and CCR-5 in U937 cells and peritoneal macrophages. Over a range of 0-1000 pg/ml recombinant human RANTES had a direct, linear effect on monocyte migration. Conditioned media and peritoneal fluid induced dose-dependent effects on monocyte migration that were correlated with concentrations of immunoreactive RANTES (as measured by enzyme-linked immunosorbent assay) and the severity of endometriosis. Heat denaturation of the RANTES protein or addition of anti-human RANTES antibodies neutralized the chemoattractant effects of conditioned media and peritoneal fluid. RANTES stimulation of monocyte recruitment may be an important pathogenetic target for the treatment of infertility and pain associated with endometriosis.
Mol Hum Reprod 2001 Feb
PMID:Chemokine bioactivity of RANTES in endometriotic and normal endometrial stromal cells and peritoneal fluid. 1116 Aug 42

The roots from Aconitum sp. plants have long been used in Chinese herbal medicine for treating pain and various heart conditions. The principal component of Aconitum remedies is usually aconitine, a site 2 neurotoxin that may induce severe neurological symptoms and cardiovascular collapse. Some Aconitum species also contain lappaconitine, the structure of which is remarkably similar to that of aconitine. In contrast to aconitine, a sodium channel agonist, lappaconitine reportedly blocks voltage-gated sodium channels in heart tissue. The results in the present study demonstrate that lappaconitine blocks cloned human heart (hH1) sodium channels under whole-cell, voltage-clamp conditions. Lappaconitine binding has several characteristics in common with the binding of site 2 neurotoxins, such as aconitine and batrachotoxin. For example, lappaconitine binds almost exclusively to open channels, but has little affect on resting or inactivated channels. Moreover, lappaconitine binding is inhibited by bupivacaine, a tertiary amine local anesthetic. Whereas site 2 neurotoxins often irreversibly modify channel kinetics, lappaconitine irreversibly blocks the channels. Finally, channels containing lysine substitutions within the local anesthetic receptor region at residues F1760 or N1765 are resistant to block by bupivacaine or lappaconitine. Given that site 2 neurotoxins and local anesthetics have nonidentical but overlapping binding regions, these data suggest that lappaconitine irreversibly blocks hH1 channels by binding to the site 2 receptor.
Mol Pharmacol 2001 Feb
PMID:Irreversible block of human heart (hH1) sodium channels by the plant alkaloid lappaconitine. 1116 Aug 52

In the present study, we have compared the antinociceptive effect of three different types of antisense oligodeoxynucleotides targeting the N-methyl-D-aspartate (NMDA) R1-subunit in mice. The probes were administrated intrathecally three times during a period of 5 days (1, 5 or 25 microg/injection), followed by evaluation using the formalin test. The antinociceptive effect was correlated to in vitro receptor binding in spinal cord sections. The tissue distribution was studied after a single injection of fluorescein-conjugated probes. The phosphodiester probe showed superficial tissue penetration after 30 min and disappeared within 2 h. The probe did, however, significantly reduce both receptor binding in laminae I and II (by 36-44% compared to saline) as well as pain behavior (32% compared to saline), without apparent side effects. The mismatched probe was ineffective at 25 microg, while some reductions in receptor binding and pain behavior were seen after 5 microg. The C-5-propyne-modified phosphorothioate probe showed pronounced tissue penetration and cellular uptake as soon as 30 min after injection which was still detectable after 24 h. Immediately after injection of the highest dose, long-lasting hind-limb paralysis was observed. Receptor binding was reduced but not in a dose-related manner. Pain behavior was significantly reduced by 40% following 25 microg of antisense probe but not after lower doses or 25 microg of mismatched probe. The 2'-O-allyl-modified probe did not significantly reduce receptor binding or pain behavior. Thus, only the phosphodiester probe showed a significant correlation between reduction in pain behavior and receptor binding. These findings demonstrate that antisense technology is associated with specificity problems, but still could provide a valuable tool to study the role of different target proteins in the drug discovery process.
Brain Res Mol Brain Res 2001 Jan 31
PMID:Antinociceptive effects after intrathecal administration of phosphodiester-, 2'-O-allyl-, and C-5-propyne-modified antisense oligodeoxynucleotides targeting the NMDAR1 subunit in mouse. 1116 68


<< Previous 1 2 3 4 5 6 7 8 9 10 Next >>