Mediator complex

RNA polymerase II (Pol II) is a 12 subunit protein complex from yeast to human that is required for gene expression. Gdown1 containing Pol II [Pol II (G)] is a special form of Pol II that is catalytically inactive and heavily depends on the 30-subunit Mediator complex for its activator and basal dependent function in vitro. Here we report for the first time, the identification and the generation of a 15-subunit human Mediator complex via the novel multibac baculovirus expression system that is fully responsive to Pol II (G).

9p thiencuuchu 27-11-2021 21 3   Download

At the end of the session, participants should be able to: understand the complexity of drugs and classification of the drugs, define the society and understand the relation between drugs and society, understand the various interventions that can be used to mediate the impact of drugs on society.

43p tuoihaimuoi32 19-06-2014 74 5   Download

The plastid transcription kinase (PTK), a component of the major RNA polymerase complex from mustard chloroplasts, has been implicated in redox-mediated regulation of plastid gene expression. A cloning strategy to define the PTK gene(s) resulted in the isolation of a full-length cDNA for a protein with overall high homology with the a subunit of cytosolic casein kinase (CK2) that contained an N-terminal extension for a putative plastid transit peptide.

9p system191 01-06-2013 45 4   Download

Haematopoiesis, the differentiation of haematopoietic stem cells and progenitors into various lineages, involves complex interactions of transcription factors that modulate the expression of downstream genes and mediate proliferation and differentiation signals. Commitment of pluripotent haematopoietic stem cells to the erythroid lineage induces erythropoiesis, the production of red blood cells. This process involves a concerted progression through an erythroid burst forming unit (BFU-E), an erythroid colony forming unit (CFU-E), proerythroblast and an erythroblast....

12p research12 01-06-2013 47 4   Download

Nitrogen monoxide (NO) is a cytotoxic effector molecule produced by macrophages that results in Fe mobilization from tumour target cells which inhibits DNA synthesis and mitochondrial respiration. It is well known that NO has a high affinity for Fe, and we showed that NO-mediated Fe mobilization is markedly potentiated by glutathione (GSH) generated by the hexose monophosphate shunt [Watts, R.N. & Richardson, D.R. (2001) J. Biol. Chem. 276, 4724–4732]. We hypothesized that GSH completes the coordination shell of an NO–Fe complex that is released from the cell.

10p research12 01-06-2013 47 3   Download

The centromere–kinetochore complex is a highly specialized chromatin domain that both mediates and monitors chromosome–spindle interactions responsible for accurate partitioning of sister chromatids to daughter cells. Centromeres are distinguished from adjacent chromatin by specific patterns of histone modification and the presence of a centromere-specific histone H3 variant (e.g. CENP-A). Centromere-proximal regions usually correspond to sites of avid and persistent sister chromatid cohesion mediated by the conserved cohesin complex.

15p research12 01-06-2013 49 4   Download

Prosaposin is a neurotrophic factor that has been demonstrated to mediate trophic signalling events in different cell types; it distributes to surface membranes of neural cells and also exists as a secreted protein in different body fluids. Prosaposin was demonstrated to form tightly bound complexes with a variety of gangliosides, and a functional role has been suggested for ganglioside–prosaposin complexes.

10p research12 29-04-2013 43 5   Download

ThemaltoseATP-binding cassette transporter ofSalmonella typhimurium is composed of a membrane-associated com-plex (MalFGK2) and a periplasmic receptor (MalE). In addition to its role in transport, the complex acts as a repressor ofmaltose-regulatedgene expressionand is subject to inhibition in the process of inducer exclusion. These activities are thought to be mediated by interactions of the ATPase subunit, MalK, with the transcriptional activator, MalT, and nonphosphorylated enzyme IIA of the glucose phosphotransferase system, respectively. ...

12p research12 23-04-2013 35 3   Download

Previous results have shown that theoncoembryonicmarker a-fetoprotein (AFP) is able to induce apoptosis in tumor cells through activation of caspase 3, bypassing Fas-dependent and tumor necrosis factor receptor-dependent signaling. In this study we further investigate the molecular interactions involvedin the AFP-mediatedsignaling of apoptosis. We show that AFP treatment of tumor cells is accompaniedby cytosolic translocation of mitochondrial cytochromec.

12p tumor12 20-04-2013 44 2   Download

a2 -Macroglobulin (a2M) is an abundant glycoprotein with the intrinsic capacity for capturing diverse proteins for rapid delivery into cells. After internalization by the receptor-mediated endocytosis,a2M-protein complexes were rapidly degraded in the endolysosome system. Although this is an importantpathway for clearanceofbotha2Mandbiological targets, little is known about the nature ofa2M degradation in the endolysosome system.

10p tumor12 20-04-2013 33 3   Download

Thec-secretase complex mediates the final proteolytic event in Alzheimer’s disease amyloid-bbiogenesis. This membrane complex of presenilin, ante-rior pharynx defective, nicastrin, and presenilin enhancer-2 cleaves the C-terminal 99-amino acid fragment of the amyloid precursor protein intra-membranously atc-sites to form C-terminally heterogeneous amyloid-b and cleaves at ane-site to release the intracellular domain or e-C-terminal fragment.

14p fptmusic 12-04-2013 39 5   Download

Complex I (NADH:ubiquinone oxidoreductase) is the largest multiprotein enzyme of the oxidative phosphorylation system. Its assembly in human cells is poorly understood and no proteins assisting this process have yet been described. A good candidate is NDUFAF1, the human homologue of Neurospora crassacomplex I chaperone CIA30. Here, we demonstrate that NDUFAF1 is a mitochondrial protein that is involved in the complex I assembly process.

10p fptmusic 12-04-2013 46 4   Download

Certain natural peptides and proteins of mammalian origin are able to bind and condense plasmid DNA, a prerequisite for the formation of transfec-tion-competent complexes that facilitate nonviral gene delivery. Here we have generated recombinant derivatives of the human high-mobility group (HMG) protein HMGB2 and investigated their potential as novel protein-based transfection reagents.

16p fptmusic 11-04-2013 40 1   Download

p38 Mitogen-activated protein kinase alpha (p38 MAPKa) is a member of the MAPK family. It is activated by cellular stresses and has a number of cellular substrates whose coordinated regulation mediates inflammatory responses. In addition, it is a useful anti-inflammatory drug target that has a high specificity for Ser-Pro or Thr-Pro motifs in proteins and contains a number of transcription factors as well as protein kinases in its catalog of known substrates.

15p fptmusic 11-04-2013 42 3   Download

A majority of human proteins have a modular composition, and are constructed of domains that mediate biomolecular inter-actions, and in some cases have catalytic functions. Interaction domains (i.e. SH2 domains) can regulate catalytic activity, direct enzymes to their substrates, and mediate the formation of multi-protein regulatory complexes, and of extended protein net-works. The functions of such modular protein interactions in phosphotyrosine-based signaling pathways, cytoskeletal organ-ization and cell polarity will be explored.

35p fptmusic 11-04-2013 43 3   Download

The phosphoproteins HPrSerP and CrhP are the main effectors for CcpA-mediated carbon catabolite regulation (CCR) inBacillus subtilis. Complexes of CcpA with HPrSerP or CrhP regulate genes by binding to the catabolite responsive elements (cre). We present a quantitative analysis of HPrSerP and CrhP interaction with CcpA by surface plasmon resonance (SPR) revealing small and similar equilibrium constants of 4.8 ± 0.4 lm for HPrSerP–CcpA and 19.1 ± 2.5 lmfor CrhP–CcpA complex dissoci-ation.

12p awards 06-04-2013 39 2   Download

The pulmonary surfactant prevents alveolar collapse and is required for normal pulmonary function. One of the important components of the surfactant besides phos-pholipids is surfactant-associated protein C (SP-C). SP-C shows complex oligomerization behavior and a transition to b-amyloid-like fibril structures, which are not yet fully understood. Besides this nonspecific oligomerization, MS and chemical cross-linking data combined with CD spectra provide evidence of a specific, mainlya-helical, dimer at lowto neutral pH....

7p dell39 03-04-2013 44 4   Download

Ligand-induced oligomerization of receptors is a key step in initiating growth factor signaling. Nevertheless, complex biological responses often require additionaltrans-signaling mechanisms involving two or more signaling cascades. For cells of neuronal origin, it was shown that neurotrophic effects evoked by nerve growth factor or other neurotro-phins dependhighlyon the cooperativitywith cytokines that belong to the transforming growth factor b (TGF-b) superfamily.

12p dell39 03-04-2013 31 3   Download

In the yeast Saccharomyces cerevisiae, plasma membrane H + -ATPase is activated by d-glucose. We found that in the absence of glucose, this enzyme forms a complex with acetylated tubulin. Acetylated tubulin usu-ally displays hydrophilic properties, but behaves as a hydrophobic com-pound when complexed with H + -ATPase, and therefore partitions into a detergent phase.

11p dell39 27-03-2013 49 6   Download

The suppressors of cytokine signalling (SOCS) proteins inhibit cytokine signalling by direct interaction with Janus kinases (JAKs) or activated cytokine receptors. In addition to the N-ter-minal and SH2 domains that mediate these interactions, SOCS proteins contain a C-terminal SOCS box. Evidence suggests SOCS box-containing proteins act as part of an elongin-cullin-SOCS (ECS) E3 ubiquitin ligase complex, marking target pro-teins for degradation.

35p inspiron33 26-03-2013 57 6   Download