Cellular Interactions

This study investigated the in vitro effects of ZnO NP and chemical UV filters commonly used sunscreens on the function of immortalised and primary skin cells. ZnO particulates (30 nm, 80 nm and 200 nm) were compared to the chemical UV filters: butylmethoxydibenzoylmethane (BMDBM) ethylhexylmethoxycinnamate (EHMC), ethylhexylsalicylate (EHS), homomenthylsalicylate (HMS) and 4-methylbenzylidenecamphor (MBC). Human epidermal keratinocytes (NHEK), epidermal melanocytes (NHEM), dermal fibroblasts (NHDF) and the immortalised keratinocyte HaCaT cell line were used in this study.

324p runthenight05 01-03-2023 12 3   Download

Studies on nanoparticle-protein interaction have also not been studied. This would give information on ratio influence on the structural alteration of EGCg in EGCg-AuNPs and its functionality in vivo. Herein, the optimisation of EGCg-AuNPs will be determined with a large pool of stoichiometric synthesises of gold and EGCg. These optimised EGCg-AuNPs would then be studied with bovine serum albumin (BSA) for protein interactions, binding and thermodynamics.

177p runthenight07 01-03-2023 11 3   Download

Hepatopoietin (HPO) is a novel human hepatotrophic growth factor. Recently, we demonstrated that the extra-cellular ligand form of HPO can stimulate proliferation of hepatic cells via its specific receptor, which is on the surface of these cells.Also, the intracellular formofHPOpotentiates the transcriptional factor AP-1. Intriguingly, a variety of HPO complexes with different molecular masses were detected in hepatocytes.

6p research12 23-04-2013 26 5   Download

Virus infection results in the activation of a set of cellular genes involved in host antiviral defense. IRF-3 has been identifiedas a critical transcription factor in this process. The activationmechanismof IRF-3 is not fully elucidated,yet it involves a conformational change triggered by the virus-dependent phosphorylation of its C-terminus. This con-formational change leads to nuclear accumulation,DNA binding and transcriptional transactivation.

10p tumor12 22-04-2013 40 3   Download

Eukaryotic initiation factor 4E (eIF4E) plays an important role inmRNA translation by binding the 5¢-cap structure of themRNAand facilitating the recruitment to themRNAof other translation factors and the 40S ribosomal subunit. eIF4E can interact either with the scaffold protein eIF4Gor withrepressor proteins termed eIF4E-binding proteins (4E-BPs). Highlevels of expression can disrupt cellular growthcontrol and are associated withhuman cancers.

10p tumor12 22-04-2013 38 2   Download

Protein–lipid interactions are important for protein targeting, signal trans-duction, lipid transport, and the maintenance of cellular compartments and membranes. Specific lipid-binding protein domains, such as PH, FYVE, PX, PHD, C2 and SEC14 homology domains, mediate interactions between proteins and specific phospholipids.

11p fptmusic 12-04-2013 43 2   Download

Cdc37 is a molecular chaperone that interacts with a range of clients and co-chaperones, forming various high molecular mass complexes. Cdc37 sequence homology among species is low. High homology between yeast and metazoan proteins is restricted to the extreme N-terminal region, which is known to bind clients that are predominantly protein kinases.

12p fptmusic 11-04-2013 18 1   Download

Due to the unavoidable nonbiological variations accompanying many experiments, it is imperative to consider a way of unravelling the functional interaction structure of a cellular network (e.g. signalling cascades or gene networks) by using the qualitative information of time-series experimental data instead of computation through the measured absolute values.

10p fptmusic 11-04-2013 50 3   Download

Protein aggregation is central to most neurodegenerative diseases, as shown by familial case studies and by animal models. A modified ‘amyloid cas-cade’ hypothesis for Alzheimer’s disease states that prefibrillar oligomers, also called amyloid-b-derived diffusible ligands or globular oligomers, are the responsible toxic agent. It has been proposed that these oligomeric spe-cies, as shown for amyloid-b, b2 -microglobulin or prion fragments, exert toxicity by forming pores in membranes, initiating a cascade of detrimental events for the cell. ...

10p awards 06-04-2013 42 3   Download

The leader proteinase (L pro ) of foot-and-mouth disease virus (FMDV) ini-tially cleaves itself from the polyprotein. Subsequently, L pro cleaves the host proteins eukaryotic initiation factor (eIF) 4GI and 4GII. This prevents protein synthesis from capped cellular mRNAs; the viral RNA is still trans-lated, initiating from an internal ribosome entry site. L pro cleaves eIF4GI between residues G674 and R675. We showed previously, however, that L pro binds to residues 640–669 of eIF4GI.

10p awards 06-04-2013 39 4   Download

BacterialRNApolymerase (RNAP) is the central enzyme of gene expression that is responsible for the synthesis of all types of cellular RNAs. The process of transcription is accompanied by complex structural rearrangements of RNAP. Despite the recent progress in structural studies of RNAP, detailed mechanisms of conformational changes of RNAP that occur at different stages of transcription remain unknown.

11p awards 05-04-2013 44 2   Download

The AAA-peroxins Pex1p and Pex6p play a critical role in peroxisome bio-genesis but their precise function remains to be established. These two peroxins consist of three distinct regions (N, D1, D2), two of which (D1, D2) contain a conserved
230 amino acid cassette, which is common to all ATPases associated with various cellular activities (AAA). Here we show that Pex1p and Pex6p from Saccharomyces cerevisiaedo interact in vivo. We assigned their corresponding binding sites and elucidated the importance of ATP-binding and -hydrolysis of Pex1p and Pex6p for their interaction. ...

12p awards 05-04-2013 44 3   Download

Cellular regulation is a result of complex interactions arising from DNA–protein and protein–protein binding, autoreg-ulation, and compartmentalization and shuttling of regula-tory proteins. Experiments in molecular biology have identified these mechanisms recruited by a regulatory net-work.Mathematicalmodelsmaybe used to complement the knowledge-base provided byin vitroexperimental methods. Interactions identified byin vitroexperiments can lead to the hypothesis of multiple candidate models explaining the in vivo mechanism. ...

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Penetratin is a 16-residue peptide [RQIKIWFQNRRM KWKK(43–58)]derived from the Antennapedia homeo-domain, which is used as a vector for cellular internalization of hydrophilic molecules. In order to unravel themembrane translocation mechanism, we synthesized new penetratin variants. The contribution of the positively charged residues was studied by double substitutions of Lys and/or Arg resi-dues to Ala, while the specific contribution of Trp48 and Trp56 was studied by individual substitution of these resi-dues to Phe. ...

11p dell39 03-04-2013 45 3   Download

The polyamines putrescine, spermidine and spermine are organic cations shown to participate in a bewildering num-ber of cellular reactions, yet their exact functions in inter-mediary metabolism and specific interactions with cellular components remain largely elusive. Pharmacological inter-ventions have demonstrated convincingly that a steady supply of these compounds is a prerequisite for cell prolif-eration to occur.

18p dell39 03-04-2013 41 5   Download

The human 2¢)5¢ oligoadenylate synthetases (OAS) form a conserved family of interferon-induced proteins consisting of four genes:OAS1, OAS2, OAS3and the 2¢)5¢ oligo-adenylate synthetase-like gene (OASL). When activated by double-strandedRNA,OAS1–3polymerizeATP into2¢)5¢-linkedoligoadenylates; 2¢)5¢-linkedoligoadenylates, in turn, activate a latent endoribonuclease that degrades viral and cellular RNAs. In contrast, while the p59 OASLprotein is highlyhomologous to theOAS family (45%identity), its 350 amino acid N-terminal domain lacks 2¢)5¢ oligoadenylate synthetase activity. ...

9p dell39 03-04-2013 43 5   Download

Patterns of protein interactions are organized around complex heterogene-ous networks. Their architecture has been suggested to be of relevance in understanding the interactome and its functional organization, which per-vades cellular robustness. Transcription factors are particularly relevant in this context, given their central role in gene regulation.

12p dell39 27-03-2013 39 3   Download

G-rich GT oligonucleotides with a different content of G clusters have been evaluated for their ability to exert cytotoxicity and to bind to nuclear-associated proteins in T-lymphoblast CCRF-CEM cells. Only the oligomers that did not form G-based structures or had a poor structure, under physiological conditions, were able to exert significant cellular growth inhibition effect.

12p inspiron33 26-03-2013 37 3   Download

The vertex of the adenoviral capsid is formed by the penton, a complex of two proteins, the pentameric penton base and the trimeric fiber protein. The penton contains all necessary components for viral attachment and entry into the host cell. After initial attachment via the head domain of the fiber protein, the penton base interacts with cellular integrins through an Arg-Gly-Asp (RGD) motif located in a hypervariable surface loop, trigger-ing virus internalization.

10p inspiron33 25-03-2013 40 6   Download

The human 57 kDa Ki-1 antigen (Ki-1⁄57) is a cytoplasmic and nuclear protein, associated with Ser⁄Thr protein kinase activity, and phosphorylat-ed at the serine and threonine residues upon cellular activation. We have shown that Ki-1⁄57 interacts with chromo-helicase DNA-binding domain protein 3 and with the adaptor⁄signaling protein receptor of activated kinase 1 in the nucleus.

16p inspiron33 25-03-2013 35 4   Download