The formin mDia2 stabilizes microtubules independently of its actin nucleation activity

A critical microtubule (MT) polarization event in cell migration is the Rho/mDia-dependent stabilization of a subset of MTs oriented toward the direction of migration. Although mDia nucleates actin filaments, it is unclear whether this or a separate activity of mDia underlies MT stabilization. We generated two actin mutants (K853A and I704A) in a constitutively active version of mDia2 containing formin homology domains 1 and 2 (FH1FH2) and found that they still induced stable MTs and bound to the MT TIP proteins EB1 and APC, which have also been implicated in MT stabilization. A dimerization-impaired mutant of mDia2 (W630A) also generated stable MTs in cells. We examined whether FH1FH2mDia2 had direct activity on MTs in vitro and found that it bound directly to MTs, stabilized MTs against cold- and dilution-induced disassembly, and reduced the rates of growth and shortening during MT assembly and disassembly, respectively. These results indicate that mDia2 has a novel MT stabilization activity that is separate from its actin nucleation activity.     

Complete genome sequence of Hirschia baltica type strain (IFAM 1418(T))

The family Hyphomonadaceae within the Alphaproteobacteria is largely comprised of bacteria isolated from marine environments with striking morphologies and an unusual mode of cell growth. Here, we report the complete genome sequence Hirschia baltica, which is only the second a member of the Hyphomonadaceae with a published genome sequence. H. baltica is of special interest because it has a dimorphic life cycle and is a stalked, budding bacterium. The 3,455,622 bp long chromosome and 84,492 bp plasmid with a total of 3,222 protein-coding and 44 RNA genes were sequenced as part of the DOE Joint Genome Institute Program CSP 2008.     

Antidotes to anthrax lethal factor intoxication. Part 2: structural modifications leading to improved in vivo efficacy

New anthrax lethal factor inhibitors (LFIs) were designed based upon previously identified potent inhibitors 1a and 2. Combining the new core structures with modifications to the C2-side chain yielded analogs with improved efficacy in the rat lethal toxin model.     

Complete genome sequence and updated annotation of Desulfovibrio alaskensis G20

Desulfovibrio alaskensis G20 (formerly Desulfovibrio desulfuricans G20) is a Gram-negative mesophilic sulfate-reducing bacterium (SRB), known to corrode ferrous metals and to reduce toxic radionuclides and metals such as uranium and chromium to sparingly soluble and less toxic forms. We present the 3.7-Mb genome sequence to provide insights into its physiology.     

Skeletal modification by microorganisms and their environments

Abstract

Microstructural post mortem changes to skeletal tissues by microorganisms are driven by several factors including the death history of an animal, its decomposition trajectory, and the depositing environment itself. The study we describe here brings together material from recent and fossil contexts that are depositionally distinct from a terrestrial-marine transitionary shoreline environment. We compare these changes with those of marine environments previously identified in the Mary Rose material, and those of continental waters (lakes) previously identified in the Cerro de la Garita (Concud) site, and we document this against bacterially related changes observed from terrestrial contexts. A new microstructural change identified in material from terrestrial sites is also described relating to rootlet damage. By considering microstructural change in skeletal tissues, it is maybe possible to ascribe environmental context, or, to better understand the complexity of material presented by transitionary environments.     

Solvent specified conformation in poly(alpha-L-glutamic acid) thin films

The ability to control conformational properties of polypeptides in their films is of considerable interest for many possible applications of these materials. By rational choice of the solvent system for film fabrication, control over the conformation of the main chain, the intermolecular hydrogen bonding in the side chain is easily achieved in poly(alpha-L-glutamic acid) (PLGA) thin films. The spectral data from circular dichromism (CD), FT-IR, and solid state (13)C NMR spectroscopies suggest that the beta-sheet conformation is dominant in PLGA films cast from trifluoroacetic acid (TFA) solution, whereas the right-handed alpha-helix is dominant in those cast from pyridine or DMF solution. In comparison with films cast from TFA solutions, the films fabricated from pyridine or DMF solutions exhibit strong intermolecular hydrogen bondings between -COOH groups and have a more ordered arrangement of side chains. Moreover, the extent of alpha-helix conformation of the PLGA backbone in films cast from pyridine or DMF solution is several times higher than that observed in the PLGA powder precipitated from aqueous solution at pH 4. All spectroscopic studies indicate clearly that the solvents (used for casting these films) play a crucial role in directing the organization of PLGA in these thin films.     

Genome sequence of the clover-nodulating Rhizobium leguminosarum bv. trifolii strain TA1

Rhizobium leguminosarum bv. trifolii strain TA1 is an aerobic, motile, Gram-negative, non-spore-forming rod that is an effective nitrogen fixing microsymbiont on the perennial clovers originating from Europe and the Mediterranean basin. TA1 however is ineffective with many annual and perennial clovers originating from Africa and America. Here we describe the features of R. leguminosarum bv. trifolii strain TA1, together with genome sequence information and annotation. The 8,618,824 bp high-quality-draft genome is arranged in a 6 scaffold of 32 contigs, contains 8,493 protein-coding genes and 83 RNA-only encoding genes, and is one of 20 rhizobial genomes sequenced as part of the DOE Joint Genome Institute 2010 Community Sequencing Program.     

Unconfined compression of white matter

The porous properties of brain tissue are important for understanding normal and abnormal cerebrospinal fluid flow in the brain. In this study, a poroviscoelastic model was fitted to the stress relaxation response of white matter in unconfined compression performed under a range of low strain rates. A set of experiments was also performed on the tissue samples using a no-slip boundary condition. Results from these experiments demonstrated that the rheological response of the white matter is primarily governed by the intrinsic viscoelastic properties of the solid phase. The permeability of white matter was found to be of the order of 10(-12) m4/Ns.