Volume 8 Issue 5, May 2012

Social media offer rapid and informal mechanisms to exchange ideas and build ties within the community.

Lymphoid tyrosine phosphatase (LYP) is often mutated in humans suffering from autoimmune diseases. A recent study proposes a mechanism by which LYP can cause these diseases and suggests that drugs against LYP could be a useful treatment.

RNA molecules have diverse functional roles, including silencing genes, catalyzing biochemical reactions and sensing chemicals that control gene expression. Biologists have drawn from nature's toolbox to construct engineered RNA molecules with versatile capabilities and can now begin to automate the design of libraries of regulatory RNAs.

Sensing of the plant hormone auxin involves formation of a co-receptor complex consisting of an F-box protein and an AUXIN/INDOLE-3-ACETIC ACID (Aux/IAA) transcriptional repressor. Distinct co-receptor combinations might provide cells with an unexpectedly broad range of auxin-sensing capacities and contribute to diverse transcriptional programs activated by different auxin levels in various developmental contexts.

Chromatin structure and its modulation by epigenetic mechanisms represent a complex system that regulates gene expression in cells. Chemical biology approaches, including chemical probes, designer chromatin and molecular-level analysis of chromatin states, offer powerful mechanistic tools for understanding and manipulating chromatin at all levels of cellular organization.

Searching chemical space for biologically active molecules requires facile access to new molecular architectures. Variations in reagent, catalyst and reaction order create a programmable one-pot method that yields single stereoisomers of complex cycloadducts, including either isomer of enantiomeric pairs.

Indole, secreted by E. coli, induces oxidative-stress and phage-shock pathway genes to increase persistence, a phenomenon in which dormant bacteria are resistant to antibiotics.

N-linked glycoprotein production requires attachment of eukaryotic glycans to eukaryotic proteins. The introduction of four eukaryotic glycosyltransferases and a bacterial oligosaccharyltransferase now allows E. coli to produce and transfer a five-glycan Man₃GlcNAc₂ eukaryotic core structure to several protein targets.

The protein phosphatase LYP is known to regulate signaling in the immune system, but the regulatory mechanisms controlling LYP itself are less clear. Exploration of spatiotemporal dynamics and application of a newly identified chemical inhibitor now define a role for the kinase CSK in dialing down LYP activity.

Antisense RNA sequences are attractive 'parts' for use as regulatory devices in synthetic biology applications. Synthesis and testing of an RNA library specific to the translation initiation region now allows analysis and forward design of these sequences, leading to a family of mutually orthogonal regulators.

Diazepam-bound GABA_A receptor models used for virtual screening lead to discovery of new ligands that modulate GABA_A receptors expressed in Xenopus laevis oocytes via their benzodiazepine binding site.

Chemically inducible protein dimerization serves as a useful tool to investigate biological systems and construct synthetic circuits. Optimization of a protein-protein interaction dependent on the plant hormone gibberellin yields a portable dimerization system that can be combined with rapamycin to assemble logic gates.

A covalent inhibitor based on an electron-deficient olefin scaffold reversibly and selectively inhibits the p90 ribosomal protein S6 kinase RSK.

Auxin is perceived by a co-receptor complex that contains a TIR1 F-box protein and an Aux/IAA transcriptional repressor. The combinatorial diversity of auxin co-receptor complexes and their distinct spectra of affinities offer a means to tune plant cell sensitivity to a wide range of auxin concentrations.

The diperpenoid adenanthin covalently modifies the resolving cysteine from peroxiredoxins to inhibit the reduction of hydrogen peroxide, a second messenger in cells, and thereby activates pathways that promote the differentiation of leukemia cells.