Abstract:
:Thiopurine methyltransferase (TPMT) catalyzes the S-methylation of thiopurine drugs such as 6-mercaptopurine. Levels of TPMT activity in human tissue are controlled by a common genetic polymorphism that is an important factor responsible for individual variation in thiopurine drug toxicity and therapeutic efficacy. Our goal was to purify, to obtain a partial amino acid sequence for, and to clone and express cDNA for human TPMT as a first step in determining the molecular basis for this genetic polymorphism. Human kidney TPMT was purified, the protein was subjected to limited proteolysis, and amino acid sequence information was obtained from the resultant peptide fragments. Primers based on the amino acid sequence information were used to amplify a unique sequence from human liver cDNA by use of the polymerase chain reaction. Because TPMT has been reported to be present in the colon, T84 human colon carcinoma cells were studied and were found to express TPMT activity with biochemical properties similar to those of the human kidney and liver enzymes. Oligonucleotide probes based on the human kidney TPMT amino acid sequence were then used to screen a T84 human colon carcinoma cell cDNA library. A 2.7-kilobase cDNA clone was isolated that contained an open reading frame of 735 nucleotides, which encoded a protein of 245 amino acids. The deduced amino acid sequence of the encoded protein included one 24- and two separate 12-amino acid sequences identical to those obtained by sequencing proteolytic fragments of purified human kidney TPMT. Transcripts were made in vitro from the open reading frame of the cDNA clone. These transcripts were translated in a rabbit reticulocyte lysate system, and the resulting translation product comigrated with human kidney TPMT in sodium dodecyl sulfate-polyacrylamide gel electrophoresis. The T84 cell cDNA clone, truncated within the 3' untranslated region at an Sstl restriction site, was then used to create an expression construct with the eukaryotic expression vector P91023(B), and this construct was used to transfect COS-1 cells. The transfected cells expressed a high level of TPMT enzymatic activity, and this activity displayed a pattern of inhibition by TPMT inhibitors identical to that of human kidney and T84 human colon carcinoma cell TPMT. Cloning of cDNA for this important drug-metabolizing enzyme may make it possible to define the molecular basis of the TPMT genetic polymorphism in humans.
journal_name
Mol Pharmacoljournal_title
Molecular pharmacologyauthors
Honchel R,Aksoy IA,Szumlanski C,Wood TC,Otterness DM,Wieben ED,Weinshilboum RMsubject
Has Abstractpub_date
1993-06-01 00:00:00pages
878-87issue
6eissn
0026-895Xissn
1521-0111journal_volume
43pub_type
杂志文章abstract::In the search for 1-[(2-hydroxyethoxy)methyl]-6-(phenylthio)thymine derivatives, we have found 6-benzyl-1-(ethoxymethyl)-5-isopropyl-uracil (MKC-442) to be a highly potent and selective inhibitor of human immunodeficiency virus type 1 (HIV-1) reverse transcriptase (RT). The IC50 value of MKC-442 for HIV-1 RT was 8 nM....
journal_title:Molecular pharmacology
pub_type: 杂志文章
doi:
更新日期:1993-10-01 00:00:00
abstract::Multidrug resistance protein (MRP) 4 transports a variety of endogenous and xenobiotic organic anions. MRP4 is widely expressed in the body and specifically localized to the renal apical proximal tubule cell membrane, where it mediates the excretion of these compounds into urine. To characterize the MRP4 substrate-bin...
journal_title:Molecular pharmacology
pub_type: 杂志文章
doi:10.1124/mol.107.043661
更新日期:2008-10-01 00:00:00
abstract::Prokaryotes produce a variety of toxins that affect genomic function of both eukaryotes and prokaryotes. The 375-base pair bacterial gene Streptoalloteichus hindustanus (Sh) ble encodes a small protein, Streptoalloteichus hindustanus bleomycin resistance protein (BRP), that inhibits in vitro DNA cleavage by the prokar...
journal_title:Molecular pharmacology
pub_type: 杂志文章
doi:
更新日期:1993-12-01 00:00:00
abstract::Ethylketocyclazocine (EKC) binds to two sites on NCB-20 neuroblastoma X Chinese hamster brain hybrid cells (KDH = 2 nM, Bmax = 21,000 sites/cell; KDL = 27 nM, Bmax = 140,000 sites/cell. The high-affinity site has been characterized as a delta opiate receptor. The low-affinity site is relatively benzomorphan-specific; ...
journal_title:Molecular pharmacology
pub_type: 杂志文章
doi:
更新日期:1983-03-01 00:00:00
abstract::We demonstrated previously that nonsteroidal anti-inflammatory drugs (NSAIDs) increased p27(Kip1) by inhibiting protein degradation to suppress the proliferation of human lung cancer cells. In this study, we elucidate the molecular mechanism by which NSAIDs modulate p27(Kip1) proteolysis. Immunoblotting and in vitro u...
journal_title:Molecular pharmacology
pub_type: 杂志文章
doi:10.1124/mol.62.6.1515
更新日期:2002-12-01 00:00:00
abstract::The bisdioxopiperazines such as (+)-(S)-4,4'-propylenedi-2,6-piperazinedione (dexrazoxane; ICRF-187), 1,2-bis(3,5-dioxopiperazin-1-yl)ethane (ICRF-154), and 4,4'-(1,2-dimethyl-1,2-ethanediyl)bis-2,6-piperazinedione (ICRF-193) are agents that inhibit eukaryotic topoisomerase II, whereas their ring-opened hydrolysis pro...
journal_title:Molecular pharmacology
pub_type: 杂志文章
doi:10.1124/mol.107.036970
更新日期:2007-10-01 00:00:00
abstract::Dantrolene was recently identified as a novel inhibitor of the plasmodial surface anion channel (PSAC), an unusual ion channel on Plasmodium falciparum-infected human red blood cells. Because dantrolene is used clinically, has a high therapeutic index, and has desirable chemical synthetic properties, it may be a lead ...
journal_title:Molecular pharmacology
pub_type: 杂志文章
doi:10.1124/mol.104.010553
更新日期:2005-07-01 00:00:00
abstract::Ovarian cancer is the leading cause of death from gynecological malignancy and has the worst prognosis of all gynecological cancers. Vascular endothelial growth factor (VEGF) plays an important role in ovarian cancer development. 9-beta-D-Arabinofuranosyl-2-fluoroadenine (Fara-A), a nucleotide analog, is frequently us...
journal_title:Molecular pharmacology
pub_type: 杂志文章
doi:10.1124/mol.66.1.178
更新日期:2004-07-01 00:00:00
abstract::Healing of gastrointestinal mucosal lesions occurs through two processes: an early one involving cell migration and a later one in which cell division replaces lost cells. Both processes require the presence of polyamines, but the mechanism of action of these compounds is unknown. In the present study, we examined the...
journal_title:Molecular pharmacology
pub_type: 杂志文章
doi:
更新日期:1995-10-01 00:00:00
abstract::Ethanol (ETOH) can cause apoptotic death of neurons by depleting GSH with an associated increase in oxidative stress. The current study illustrates a means to overcome this ETOH-induced neurotoxicity by enhancing GSH through boosting Nrf2, a transcription factor that controls GSH homeostasis. ETOH treatment caused a s...
journal_title:Molecular pharmacology
pub_type: 杂志文章
doi:10.1124/mol.111.073262
更新日期:2011-12-01 00:00:00
abstract::Notch-1 (Notch) is a cell surface receptor that regulates cell-fate decisions in the developing nervous system, and it may also have roles in synaptic plasticity in the adult brain. Binding of its ligands results in the proteolytic cleavage of Notch by the γ-secretase enzyme complex, thereby causing the release of a N...
journal_title:Molecular pharmacology
pub_type: 杂志文章
doi:10.1124/mol.111.071076
更新日期:2011-07-01 00:00:00
abstract::Computer simulations on a new model of the alpha1b-adrenergic receptor based on the crystal structure of rhodopsin have been combined with experimental mutagenesis to investigate the role of residues in the cytosolic half of helix 6 in receptor activation. Our results support the hypothesis that a salt bridge between ...
journal_title:Molecular pharmacology
pub_type: 杂志文章
doi:10.1124/mol.61.5.1025
更新日期:2002-05-01 00:00:00
abstract::Ca2-dependent protein phosphorylations activated by calmodulin or phospholipid were studied using selective inhibitors. Both protein phosphorylations were inhibited by N-(6-aminohexyl)-5-chloro-1-naphthalenesulfonamide (W-7) and its derivatives. Kinetic analysis indicated that the primary effect of these agents was me...
journal_title:Molecular pharmacology
pub_type: 杂志文章
doi:
更新日期:1982-09-01 00:00:00
abstract::The flexible dopamine (DA) molecule exists in one or the other of its two conformational extremes (alpha- or beta-rotamer) and its receptor in the anterior pituitary gland exists in a high and a low affinity state. A series of novel, rigid DA congeners (2-substituted octahydrobenzo[f]quinolines) was synthesized and us...
journal_title:Molecular pharmacology
pub_type: 杂志文章
doi:
更新日期:1988-01-01 00:00:00
abstract::Studies were carried out to elucidate the mechanism whereby thyroid hormone (T3) induces NADPH:cytochrome P450 oxidoreductase (P450R) mRNA in rat liver in vivo. Northern blot analysis revealed that T3 treatment increases unspliced liver nuclear P450R RNA 4-fold within 8 h and that this induction precedes the induction...
journal_title:Molecular pharmacology
pub_type: 杂志文章
doi:10.1124/mol.59.5.987
更新日期:2001-05-01 00:00:00
abstract::The induction of human inducible nitric-oxide synthase (iNOS) expression depends (among other factors) on activation of the signal transducer and activator of transcription 1 (STAT1) pathway. Therefore, the STAT1 pathway may be an appropriate target for the development of inhibitors of iNOS expression. HeLa S3 cells t...
journal_title:Molecular pharmacology
pub_type: 杂志文章
doi:10.1124/mol.63.2.383
更新日期:2003-02-01 00:00:00
abstract::Metabolism of [3H]-(+/-)-trans-1,2-dihydroxy-1,2-dihydrobenz[a] anthracene by liver microsomes isolated from control, phenobarbital-treated, and 3-methylcholanthrene-treated Long-Evans rats and from 3-methylcholanthrene-treated Sprague-Dawley rats was examined. Liver microsomes from both control and phenobarbital-trea...
journal_title:Molecular pharmacology
pub_type: 杂志文章
doi:
更新日期:1983-07-01 00:00:00
abstract::The co-transfection assay is a novel functional assay using cells transiently transfected with plasmids encoding intracellular receptors and corresponding reporter genes. Using this assay, natural product extracts were tested to identify compounds that modulate intracellular receptor activity, measured as changes in r...
journal_title:Molecular pharmacology
pub_type: 杂志文章
doi:
更新日期:1995-03-01 00:00:00
abstract::Bordetella pertussis, the pathogen responsible for whooping cough, releases a soluble calmodulin-sensitive adenylate cyclase into its culture medium which enters several different types of animal cells and elevates intracellular cAMP. In this study, the influence of B. pertussis adenylate cyclase on intracellular cAMP...
journal_title:Molecular pharmacology
pub_type: 杂志文章
doi:
更新日期:1987-05-01 00:00:00
abstract::Cytochrome P450 (P450) enzymes are responsible for metabolizing drugs. Expression of P450s can directly affect drug metabolism, resulting in various outcomes in therapeutic efficacy and adverse effects. Several nuclear receptors are transcription factors that can regulate expression of P450s at both basal and drug-ind...
journal_title:Molecular pharmacology
pub_type: 杂志文章
doi:10.1124/mol.118.112235
更新日期:2018-07-01 00:00:00
abstract::The in vitro binding of [3H]LY354740, the first high affinity group II-selective metabotropic glutamate (mGlu) receptor radioligand, was characterized in rat cortical, hippocampal, and thalamic membranes as well as in rat brain sections. [3H]LY354740 binding was saturable in all regions investigated. Nonspecific bindi...
journal_title:Molecular pharmacology
pub_type: 杂志文章
doi:
更新日期:1998-02-01 00:00:00
abstract::We reported previously that protein associated with Myc (PAM) interacts with the C2 domain of type V adenylyl cyclase (ACV-C2) and that purified PAM is a potent inhibitor of Galphas-stimulated ACV activity (J Biol Chem 276:47583-47589, 2001). The present study was conducted to identify the region in PAM that inhibits ...
journal_title:Molecular pharmacology
pub_type: 杂志文章
doi:10.1124/mol.104.005355
更新日期:2005-01-01 00:00:00
abstract::G protein-coupled receptors are sensors that interact with a large variety of elements, including photons, ions, and large proteins. Not surprisingly, these receptors participate in the numerous normal physiologic processes that we refer to as health and in its perturbations that constitute disease. It has been estima...
journal_title:Molecular pharmacology
pub_type:
doi:10.1124/mol.116.106062
更新日期:2016-11-01 00:00:00
abstract::Receptors for the serine protease thrombin and for lysophospholipids are coupled to G proteins and control a wide range of cellular functions, including mitogenesis. Activators of these receptors are present in blood, and can enter the brain during central nervous system (CNS) injury. Reactive astrogliosis, a prominen...
journal_title:Molecular pharmacology
pub_type: 杂志文章
doi:10.1124/mol.64.5.1199
更新日期:2003-11-01 00:00:00
abstract::Current evidence suggests that DNA fragmentation plays an integral role in mediating cytotoxicity that results from thymidine nucleotide depletion ("thymineless death"). Recently, Ayusawa et al. [Mutat. Res. 200:221-230 (1988)] reported that dTMP starvation induces cellular processes that result in the release of 50-2...
journal_title:Molecular pharmacology
pub_type: 杂志文章
doi:
更新日期:1991-03-01 00:00:00
abstract::C57BL/6J (C57) and DBA/JBOMf (DBA) mice were used to study the role of adipose tissue as a modifier of tissue distribution, biological effects, and elimination of a lipophilic foreign chemical, 2,4,5,2',4',5'-hexachlorobiphenyl (HCB). As an indication of biological potency of the model compound, the activities of hepa...
journal_title:Molecular pharmacology
pub_type: 杂志文章
doi:
更新日期:1983-11-01 00:00:00
abstract::Our laboratory recently isolated and sequenced cDNAs encoding the microsomal flavin-containing monooxygenases (FMOs) from rabbit liver and rabbit lung. As a first step in understanding the molecular bases for the catalytic and physical differences between these enzymes, we have expressed them in COS-1 cells and compar...
journal_title:Molecular pharmacology
pub_type: 杂志文章
doi:
更新日期:1991-11-01 00:00:00
abstract::The highly conserved aspartate residue in the second transmembrane domain of G protein-coupled receptors is present in position 113 in the type 1 neurotensin receptor (NTR1) but is replaced by an Ala residue in position 79 in the type 2 neurotensin receptor (NTR2). NTR1 couples to Galphaq to stimulate phospholipase C ...
journal_title:Molecular pharmacology
pub_type: 杂志文章
doi:10.1124/mol.55.2.210
更新日期:1999-02-01 00:00:00
abstract::A central axiom of ligand-receptor theory is that agonists bind more tightly to active than to inactive receptors. However, measuring agonist affinity in inactive receptors is confounded by concomitant activation. We identified a cysteine substituted mutant γ-aminobutyric acid type A (GABAA) receptor with unique chara...
journal_title:Molecular pharmacology
pub_type: 杂志文章
doi:10.1124/mol.112.084558
更新日期:2013-06-01 00:00:00
abstract::CaV2.3 subunits are expressed in neuronal and neuroendocrine cells where they are believed to form native R-type Ca2+ channels. Although R-type currents are involved in triggering neurotransmitter and hormone secretion, little is known about their modulation. Previous studies have shown that muscarinic acetylcholine r...
journal_title:Molecular pharmacology
pub_type: 杂志文章
doi:10.1124/mol.65.2.381
更新日期:2004-02-01 00:00:00