This laboratory recently identified a human gene that encodes novel folate transporter [Homo sapiens proton-coupled (HsPCFT); SLC46A1] required for intestinal absorption. study focused on mouse (Mus musculus) PCFT (MmPCFT) and rat (Rattus norvegicus) (RnPCFT) addresses their secondary structure, specificity, tissue expression, regulation by dietary folates. Both rodent proteins traffic to the cell membrane with NH(2)- COOH-termini accessible antibodies targeted these domains only in...

The reduced folate carrier (RFC) and the proton-coupled transporter (PCFT) are ubiquitously expressed in normal malignant mammalian tissues human solid tumor cell lines. This article addresses extent to which PCFT contributes transport of pemetrexed activities this other antifolates relative RFC at physiological pH. Either or cDNA was stably transfected into a transporter-null HeLa variant achieve similar their endogenous function wild-type cells. produced comparable increases activity...

Cys-loop receptor neurotransmitter-gated ion channels are pentameric assemblies of subunits that contain three domains: extracellular, transmembrane, and intracellular. The extracellular domain forms the agonist binding site. transmembrane channel. cytoplasmic is involved in trafficking, localization, modulation by second messenger systems but its role channel assembly function poorly understood little known about structure. intracellular formed large (>100 residues) loop between...

The effect of culture age on intra- and extracellular metabolite levels as well in vitro determined specific activities enzymes central carbon metabolism was investigated during evolution for over 90 generations Saccharomyces cerevisiae CEN.PK 113-7D an aerobic glucose/ethanol-limited chemostat at a dilution rate 0.052 h−1. It found that the fluxes consumed (O2, glucose/ethanol) secreted compounds (CO2) did not change significantly entire cultivation period. However, morphological changes...

The molecular basis of general anesthetic interactions with GABA A receptors is uncertain. An accurate homology model would facilitate studies action. Construction a based on the 4 Å resolution acetylcholine receptor structure complicated by alignment uncertainty between and M3 M4 transmembrane segments. Using disulfide crosslinking we previously established orientation M2 within single subunit. resultant predicts that βM3 residue β2M286, implicated in binding, faces adjacent α1-M1 segment...

Prokaryotic members of the Cys-loop receptor ligand-gated ion channel superfamily were recently identified. Previously, receptors only known from multicellular organisms (metazoans). Contrary to metazoan receptors, prokaryotic ones consist an extracellular (ECD) and a transmembrane domain (TMD), lacking large intracellular (ICD) present in metazoa (between segments M3 M4). Using chimera approach, we added 115-amino acid ICD mammalian serotonin type 3A (5-HT3A) proton-activated Gloeobacter...

Based on the Torpedo acetylcholine receptor structure, Unwin and colleagues (Miyazawa et al., 2003; Unwin, 2005) hypothesized that transduction of agonist binding to channel gate opening involves a “pin-into-socket” interaction between αV46 at tip extracellular β 1 -β 2 loop transmembrane M2 segment M2-M3 loop. We mutated cysteine aligned positions in 5-HT 3A 3B subunit loops K81 Q70, respectively. The maximal 5-HT-activated currents receptors containing /K81C or /Q70C were markedly reduced...

Construction of a GABAA receptor homology model based on the acetylcholine (ACh) structure is complicated by low sequence similarity between and ACh M3 transmembrane segments that creates significant uncertainty in their alignment. We determined orientation M2 using disulfide cross-linking. The residues alpha1M266 (11') alpha1T267 (12') were mutated to cysteine either wild type or single mutant (alpha1V297C, alpha1A300C alpha1A305C) backgrounds. assayed spontaneous induced bond formation....

A novel series of C-3 substituted 4,6-dichloroindole-2-carboxylic acids was synthesized to investigate the influence different hydrogen-bond donor and acceptor groups at this specific position on affinity glycine site NMDA receptor. These 3-indolylmethyl derivatives with ring-open (amines, sulfonamides, amides, ureas) cyclic substituents (imidazolidin-2-ones, (thio)hydantoins) led discovery that compounds bearing a hydantoin substituent indole nucleus are most promising ones. In hydantoins,...

Drugs used to treat various disorders target GABAA receptors. To develop α subunit selective compounds, we synthesized 5-(4-piperidyl)-3-isoxazolol (4-PIOL) derivatives. The 3-isoxazolol moiety was substituted by 1,3,5-oxadiazol-2-one, 1,3,5-oxadiazol-2-thione, and 1,2,4-triazol-3-ol heterocycles with modifications the basic piperidine substituent as well substituents without nitrogen. Compounds were screened [3H]muscimol binding in patch-clamp experiments heterologously expressed αiβ3γ2...

M. Jansen, G. Mohapatra, R. A. Betensky, C. Keohane and D. N. Louis (2012) Neuropathology Applied Neurobiology 38, 213–219 Gain of chromosome arm 1q in atypical meningioma correlates with shorter progression‐free survival Aims: Atypical (World Health Organization grade II) meningiomas have moderately high recurrence rates; even for completely resected tumours, approximately one‐third will recur. Post‐operative radiotherapy may aid local control improve survival, but carries the risk side...

Nicotinic acetylcholine receptors (nAChR) are members of the Cys-loop ligand-gated ion channel superfamily. Muscle nAChR heteropentamers that assemble from two α, and one each β, γ, δ subunits. Each subunit is composed three domains, extracellular, transmembrane intracellular. The domain consists four α-helical segments (M1-M4). Pioneering structural information was obtained using electronmicroscopy Torpedo nAChR. recently solved X-ray structure first eukaryotic receptor, a truncated...

Bupropion, a clinically used antidepressant and smoking-cessation drug, acts as noncompetitive antagonist of nicotinic acetylcholine receptors (nAChRs). To identify its binding site(s) in nAChRs, we developed photoreactive bupropion analogue, (±)-2-(N-tert-butylamino)-3'-[(125)I]-iodo-4'-azidopropiophenone (SADU-3-72). Based on inhibition [(125)I]SADU-3-72 binding, SADU-3-72 binds with high affinity (IC(50) = 0.8 μM) to the Torpedo nAChR resting (closed channel) state agonist-induced...