Research Summary• Protein delivery across cellular membranes or compartments is primarily limited by low biomembrane permeability.• Many protein transduction domains (PTDs) have previously been generated, and covalently cross-linked with cargoes for cellular internalization.• An arginine-rich intracellular delivery (AID) peptide could rapidly deliver fluorescent proteins or β -galactosidase enzyme into plant and animal cells in a noncovalent fashion. The possible mechanism of this noncovalent protein transduction (NPT) may involve macropinocytosis.• The NPT via a nontoxic AID peptide provides a powerful tool characterized by its simplicity and quickness to have active proteins function in living cells in vivo . This should be of broad utility for functional enzyme assays and protein therapies in both plant biology research as well as biomedical applications.

Both bacteria and algal symbionts (genus Symbiodinium), the two major microbial partners in the coral holobiont, respond to fluctuations in the environment, according to current reports; however, little evidence yet indicates that both populations have any direct interaction with each other in seasonal fluctuation. In this study, we present field observations of a compositional change in bacteria and Symbiodinium in the coral Isopora palifera in three separate coral colonies following monthly sampling from February to November in 2008. Using massively parallel pyrosequencing, over 200 000 bacterial V6 sequences were classified to build the bacterial community profile; in addition, the relative composition and quantity of Symbiodinium clades C and D were determined by real-time PCR. The results showed that coral-associated bacterial and Symbiodinium communities were highly dynamic and dissimilar among the tagged coral colonies, suggesting that the effect of host specificity was insignificant. The coral-associated bacterial community was more diverse (Shannon index up to 6.71) than previous estimates in other corals and showed rapid seasonal changes. The population ratios between clade C and D groups of Symbiodinium varied in the tagged coral colonies through the different seasons; clade D dominated in most of the samples. Although significant association between bacteria and symbiont was not detected, this study presents a more detailed picture of changes in these two major microbial associates of the coral at the same time, using the latest molecular approaches.

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Halovirus PH1 infects Haloarcula hispanica and was isolated from an Australian salt lake. The burst size in single-step growth conditions was 50–100 PFU/cell, but cell density did not decrease until well after the rise (4–6 hr p.i.), indicating that the virus could exit without cell lysis. Virions were round, 51 nm in diameter, displayed a layered capsid structure, and were sensitive to chloroform and lowered salt concentration. The genome is linear dsDNA, 28,064 bp in length, with 337 bp terminal repeats and terminal proteins, and could transfect haloarchaeal species belonging to five different genera. The genome is predicted to carry 49 ORFs, including those for structural proteins, several of which were identified by mass spectroscopy. The close similarity of PH1 to SH1 (74% nucleotide identity) allowed a detailed description and analysis of the differences (divergent regions) between the two genomes, including the detection of repeat-mediated deletions. The relationship of SH1-like and pleolipoviruses to previously described genomic loci of virus and plasmid-related elements (ViPREs) of haloarchaea revealed an extensive level of recombination between the known haloviruses. PH1 is a member of the same virus group as SH1 and HHIV-2, and we propose the name halosphaerovirus to accommodate these viruses.

The delivery and expression of exogenous genes in plant cells have been of particular interest for plant research and biotechnology. Here, we present results demonstrating a simple DNA transfection system in plants. Short arginine-rich intracellular delivery peptide, a protein transduction domain, was capable of delivering plasmid DNA into living plant cells non-covalently. This peptide-mediated DNA delivery conferred several advantages, such as nuclear targeting, non-toxic effect, and ease of preparation without protoplast formulation. Thus, this novel technology shall provide a powerful tool to investigate gene function in vivo, and lay the foundation for the production of transgenic plants in future.

Microbial endoliths, which inhabit interior pores of rocks, skeletons and coral, are ubiquitous in terrestrial and marine environments. In this study, various colored layers stratified the endolithic environment within the skeleton of Isopora palifera; however, there was a distinct green‐pigmented layer in the skeleton (beneath the living coral tissue). To characterize diversity of endolithic microorganisms, 16S ribosomal RNA gene amplicon pyrosequencing was used to investigate bacterial communities in the green layer of eight I. palifera coral colonies retrieved from two locations on Green Island, Taiwan. The dominant bacterial group in the green layer belonged to the bacterial phylum Chlorobi, green sulfur bacteria capable of anoxygenic photosynthesis and nitrogen fixation. Specifically, bacteria of the genus Prosthecochloris were dominant in this green layer. To our knowledge, this is the first study to provide a detailed profile of endolithic bacteria in coral and to determine the prevalence of Prosthecochloris in the green layer. Based on our findings, we infer that these bacteria may have an important functional role in the coral holobiont in the nutrient‐limited coral reef ecosystem.

Plasma membranes of animal cells are generally impermeable to macromolecules. Protein transduction mediated by protein transduction domains (PTDs) covalently cross-linked to cargoes for cellular internalization has previously been demonstrated. Peptides with PTDs could be an effective way to deliver proteins into living cells or tissues in vitro. In this report, we demonstrate that arginine-rich intracellular delivery (AID) peptides are able to facilitate the delivery of proteins into animal cells and to penetrate skin tissues rapidly. This cellular internalization and transdermal delivery of proteins is mediated by non-toxic AID peptides in a non-fusion protein and non-conjugation dependent manner. The efficiency of intracellular transport is further increased in the presence of chemical enhancer oleic acid. The mechanism of the AID-mediated cellular entry may involve macropinocytosis and actin rearrangement. Thus, we confirm that direct delivery of bioactive proteins into living cells and tissues mediated by non-covalent actions of AID peptides represents a useful strategy in pharmaceutics, therapeutics and cosmetics.

BMS-663749, a phosphonooxymethyl prodrug 4 of the HIV-1 attachment inhibitor 2-(4-benzoyl-1-piperazinyl)-1-(4,7-dimethoxy-1H-pyrrolo[2,3-c]pyridin-3-yl)-2-oxoethanone (BMS-488043) (2) was prepared and profiled in a variety of preclinical in vitro and in vivo models designed to assess its ability to deliver parent drug following oral administration. The data showed that prodrug 4 had excellent potential to significantly reduce dissolution rate-limited absorption following oral dosing in humans. Clinical studies in normal healthy subjects confirmed the potential of 4, revealing that the prodrug significantly increased both the AUC and C(max) of 2 compared to a solid capsule formulation containing the parent drug upon dose escalation. These data provided guidance for further efforts to obtain an effective HIV-1 attachment inhibitor.