A non-canonical transferable signal mediates nuclear import of simian immunodeficiency virus Vpx protein

Protein transport into the nucleus is generally considered to involve specific nuclear localization signals (NLS) though it is becoming increasingly evident that efficient and well controlled import of proteins which lack a canonical NLS also occurs in cells. Vpx, a 112 amino acid protein from human immunodeficiency virus type 2 (HIV-2) and the closely related simian immunodeficiency virus (SIV) is one such protein, which does not have an identifiable canonical NLS and is yet efficiently imported to the nuclear compartment. Here we report that Vpx protein is imported to the nucleus independently of virus-encoded cofactors. When fusions of truncated versions of Vpx with full-length beta-galactosidase (beta-Gal) were tested, the region from Vpx 61 to 80 was found to be sufficient to mediate the import of the heterologous cytoplasmic protein to the nucleus. Inactivation of Vpx NLS precluded nuclear import of Vpx and reduced virus replication in non-dividing macrophage cultures, even when functional integrase and Gag matrix proteins implicated in viral nuclear import were present. Importantly, we identified and characterized a novel type of 20 amino acid transferable nuclear import signal in Vpx that is distinct from other import signals described. In addition, we show that the minimal nuclear targeting domain identified here overlaps with helical domain III (amino acid (aa) 64-82) and the structural integrity of this helical motif is critical for the nuclear import of Vpx. Taken together, these data suggest that Vpx is imported to the nucleus via a novel import pathway that is dependent on its 20 amino acid unique nuclear targeting signal, and that the nuclear import property of Vpx is critical for the optimal virus replication in non-dividing cells such as macrophages.     

Methyl Jasmonate Increases the Tropane Alkaloid Scopolamine and Reduces Natural Herbivory in Brugmansia suaveolens: Is Scopolamine Responsible for Plant Resistance?

The tropane alkaloid (TA) scopolamine is suggested to protect Brugmansia suaveolens (Solanaceae) against herbivorous insects. To test this prediction in a natural environment, scopolamine was induced by methyl jasmonate (MJ) in potted plants which were left 10?days in the field. MJ-treated plants increased their scopolamine concentration in leaves and herbivory decreased. These findings suggest a cause?Ceffect relationship. However, experiments in laboratory showed that scopolamine affect differently the performance of the specialist larvae of the ithomiine butterfly Placidina euryanassa (C. Felder & R. Felder) and the generalist fall armyworm Spodoptera frugiperda (J. E. Smith): the specialist that sequester this TA from B. suaveolens leaves was not negatively affected, but the generalist was. Therefore, scopolamine probably acts only against insects that are not adapted to TAs. Other compounds that are MJ elicited may also play a role in plant resistance against herbivory by generalist and specialist insects, and deserve future investigations.     

Changes in cholesterol levels in the plasma membrane modulate cell signaling and regulate cell adhesion and migration on fibronectin

The number and distribution of lipid molecules, including cholesterol in particular, in the plasma membrane, may play a key role in regulating several physiological processes in cells. We investigated the role of membrane cholesterol in regulating cell shape, adhesion and motility. The acute depletion of cholesterol from the plasma membrane of cells that were well spread and motile on fibronectin caused the rounding of these cells and decreased their adhesion to and motility on fibronectin. These modifications were less pronounced in cells plated on laminin, vitronectin or plastic, indicating that cholesterol-mediated changes in adhesion and motility are more specific for adhesion mediated by fibronectin-specific integrins, such as alpha5beta1. These changes were accompanied by remodeling of the actin cytoskeleton, the spatial reorganization of paxillin in the membrane, and changes to the dynamics of alpha5 integrin and paxillin-rich focal adhesions. Levels of tyrosine phosphorylation at position 576/577 of FAK and Erk1/Erk2 MAP-kinase activity levels were both lower in cholesterol-depleted than in control cells. These levels normalized only on fibronectin when cholesterol was reincorporated into the cell membrane. Thus, membrane cholesterol content has a specific effect on certain signaling pathways specifically involved in regulating cell motility on fibronectin and organization of the actin cytoskeleton.     

Nearly identical paralogs: implications for maize (Zea mays L.) genome evolution

As an ancient segmental tetraploid, the maize (Zea mays L.) genome contains large numbers of paralogs that are expected to have diverged by a minimum of 10% over time. Nearly identical paralogs (NIPs) are defined as paralogous genes that exhibit > or = 98% identity. Sequence analyses of the "gene space" of the maize inbred line B73 genome, coupled with wet lab validation, have revealed that, conservatively, at least approximately 1% of maize genes have a NIP, a rate substantially higher than that in Arabidopsis. In most instances, both members of maize NIP pairs are expressed and are therefore at least potentially functional. Of evolutionary significance, members of many NIP families also exhibit differential expression. The finding that some families of maize NIPs are closely linked genetically while others are genetically unlinked is consistent with multiple modes of origin. NIPs provide a mechanism for the maize genome to circumvent the inherent limitation that diploid genomes can carry at most two "alleles" per "locus." As such, NIPs may have played important roles during the evolution and domestication of maize and may contribute to the success of long-term selection experiments in this important crop species.     

The telomeric region of BTA18 containing a potential QTL region for health in cattle exhibits high similarity to the HSA19q region in humans

We have applied a targeted physical mapping approach, based on the isolation of bovine region-specific large-insert clones using homologous human sequences and chromosome microdissection, to enhance the physical gene map of the telomeric region of BTA18 and to prove its evolutionary conservation. The latter is a prerequisite to exploit the dense human gene map for future positional cloning approaches. Partial sequencing and homology search were used to characterize 20 BACs targeted to the BTA18q2.4-q2.6 region. We used fluorescence in situ hybridization (FISH) to create physical maps of 11 BACs containing 15 gene loci; these BACs served as anchor loci. Using these approaches, 12 new gene loci (CKM, STK13, PSCD2, IRF3, VASP, ACTN4, ITPKC, CYP2B6, FOSB, DMPK, MIA, SIX5) were assigned on BTA18 in the bovine cytogenetic map. A resolved physical map of BTA18q2.4-q2.6 was developed, which encompasses 28 marker loci and a comparative cytogenetic map that contains 15 genes. The mapping results demonstrate the high evolutionary conservation between the telomeric region of BTA18q and HSA19q.     

Activity of Sphaerotheca breviceps tadpoles in response to chemical cues of the predaceous tadpoles Hoplobatrachus tigerinus

Tadpoles of Sphaerotheca breviceps raised in the laboratory from the egg stage, and hence lacking prior experience of a predator or its odors, were tested to examine their responses to a predator’s (tadpoles of Hoplobatrachus tigerinus) water-borne chemical cues. The stimulus solution was obtained following 24 h of rearing tadpoles of H. tigerinus (one tadpole per 200 mL water) that were not fed during this period. Upon exposure to the stimulus solution the activity of S. breviceps tadpoles decreased by about 90% within 5 min. Their resting period increased significantly over baseline activity, whereas the swimming period, distance traversed, and swimming spurts declined. However, whenever a test tadpole moved, its swimming velocity was high in response to stimulus solution. The antipredatory responses declined with increase in time of storage of the stimulus solution, indicating decay of the predator’s chemical cues. The findings suggest that (1) antipredator defense strategies of S. breviceps do not require prior experience of predators, (2) the predator’s chemical cues are labile in nature, and (3) the response of prey tadpoles to such cues is similar to reported behavior of anuran tadpoles in response to real predators and alarm cues.     

A Synergistic Framework for Evaluating Business Process Improvements

The evaluation, selection, or justification of business process improvements, or business process reengineering efforts, is similar to many strategic initiatives and their justification methodologies. This similarity arises from the fact that there are multiple factors that need to be considered, many of which have long-term and broad implications for an organization. There are many intangible measures and qualitative concerns when evaluating business process improvements. These improvements necessarily have to link to the strategic objectives of the organization. The proposed methodological framework will involve the synthesis of the analytical network process and data envelopment analysis. These two techniques, when used together, can provide subjective and objective evaluations for managerial decision makers. An illustrative example provides some insights into the application of this methodology. Additional issues and research questions are also identified.     

One-Pot Multi-Component Synthesis and Biological Evaluation of Novel Indole-Pyrimidine Derivatives as Potent Anti-Cancer and Anti-Microbial Agents

Russian Journal of Bioorganic Chemistry - A series of novel hybrids of indole-pyrimidine moieties were synthesized and evaluated for their in vitro anti-cancer, in vitro anti-bacteria and...     

Development of in vitro assays for measuring the relative potency of leptospiral bacterins containing serogroups canicola,grippotyphosa, icterohaemorrhagiae,and pomona

Historically, potency testing of bacterins containing Leptospira involved a hamster vaccination-challenge assay. The United States Department of Agriculture (USDA) has long recognized that an in vitro system has several inherent advantages over the animal model. This is a review of the work performed at the USDA to replace the hamster vaccination-challenge model used to test Leptospira bacterins. The work covered a span of approximately 20 years and resulted in the development of USDA monoclonal antibody based enzyme-linked immunosorbent assays (ELISAs) for the quantitation of antigen in bacterins containing Leptospira serogroups canicola, icterohaemorrhagiae, pomona, and grippotyphosa. The monoclonal antibodies used in the assay a) recognize lipopolysaccharide-like epitopes on the surface of the whole cell, b) agglutinate the homologous leptospiral serovars but do not agglutinate heterologous leptospiral serovars or heterologous bacterial species, and c) passively protect hamsters against a homologous challenge but fail to protect hamsters against heterologous challenges. Once developed, the performance of each ELISA was evaluated at the USDA followed by industry evaluation. Serials that passed the hamster vaccination-challenge assay yielded ELISA relative potency values of 1.0 or greater. These ELISAs have been shown to be a reproducible, sensitive, specific, and inexpensive alternative to the current Codified hamster potency assay.