Red and green algal origin of diatom membrane transporters: insights into environmental adaptation and cell evolution

Membrane transporters (MTs) facilitate the movement of molecules between cellular compartments. The evolutionary history of these key components of eukaryote genomes remains unclear. Many photosynthetic microbial eukaryotes (e.g., diatoms, haptophytes, and dinoflagellates) appear to have undergone serial endosymbiosis and thereby recruited foreign genes through endosymbiotic/horizontal gene transfer (E/HGT). Here we used the diatoms Thalassiosira pseudonana and Phaeodactylum tricornutum as models to examine the evolutionary origin of MTs in this important group of marine primary producers. Using phylogenomics, we used 1,014 diatom MTs as query against a broadly sampled protein sequence database that includes novel genome data from the mesophilic red algae Porphyridium cruentum and Calliarthron tuberculosum, and the stramenopile Ectocarpus siliculosus. Our conservative approach resulted in 879 maximum likelihood trees of which 399 genes show a non-lineal history between diatoms and other eukaryotes and prokaryotes (at the bootstrap value ≥70%). Of the eukaryote-derived MTs, 172 (ca. 25% of 697 examined phylogenies) have members of both red/green algae as sister groups, with 103 putatively arising from green algae, 19 from red algae, and 50 have an unresolved affiliation to red and/or green algae. We used topology tests to analyze the most convincing cases of non-lineal gene history in which red and/or green algae were nested within stramenopiles. This analysis showed that ca. 6% of all trees (our most conservative estimate) support an algal origin of MTs in stramenopiles with the majority derived from green algae. Our findings demonstrate the complex evolutionary history of photosynthetic eukaryotes and indicate a reticulate origin of MT genes in diatoms. We postulate that the algal-derived MTs acquired via E/HGT provided diatoms and other related microbial eukaryotes the ability to persist under conditions of fluctuating ocean chemistry, likely contributing to their great success in marine environments.     

Architecture and characterization of sarcosine oxidase from Thermococcus kodakarensis KOD1

Sarcosine oxidase (SOX) catalyzes the oxidation of the methyl group in sarcosine and transfer of the oxidized methyl group into the one-carbon metabolic pool. Here, we separately cloned and expressed α and β subunit of SOX from Thermococcus kodakarensis KOD1 (TkSOX) in Escherichia coli and the recombinant proteins were purified to homogeneity. Gel filtration chromatography and transmission electron microscopy analysis showed that the α subunit formed a dimeric structure and behaved as an NADH dehydrogenase; β subunit was a tetramer that had sarcosine oxidase and l-proline dehydrogenase activity. The TkSOX complex assembled into the hetero-octameric (αβ)₄ form and had NADH dehydrogenase activity. Gold-label analysis indicated that α and β subunits were oriented in the alternative form. Based on these results, we suggested that TkSOX was a multifunctional enzyme and that each subunit and (αβ)₄ complex may separately exist as a function enzyme in different conditions.     

Comparison of protein expression profiles of different stages of lymph nodes metastasis in breast cancer

Breast cancer is the most common cancer among women worldwide. Breast cancer metastasis primarily happens through lymphatic system, where the extent of lymph node metastasis is the major factor influencing staging, prognosis and therapeutic decision of the disease. We aimed to study the protein expression changes in different N (regional lymph nodes) stages of breast cancer. Protein expression profiles of breast cancerous and adjacent normal tissues were mapped by proteomics approach that comprises of two-dimensional polyacrylamide gel electrophoresis (2D-PAGE) and tandem mass spectrometry (LC-MS/MS) analysis. Calreticulin and tropomyosin alpha 3 chains were the common up-regulated proteins in N0, N1 and N2 stages of breast cancer. Potential biomarker for each N stage was HSP 70 for N0, 80 k protein H precursor and PDI for N1 stage while 78 kDa glucose-regulated protein was found useful for N2 stage. In addition, significant up-regulation of PDI A3 was detected only in the metastasized breast cancer. The up-regulation expression of these proteins in cancerous tissues can potentially use as indicators for diagnosis, treatment and prognosis of different N stages of breast cancer.     

Spatiotemporal distribution of the hemlock woolly adelgid predator Laricobius nigrinus after release in eastern hemlock forests

• 1 Post‐release distributions of Laricobius nigrinus, a biological control predator of hemlock woolly adelgid Adelges tsugae Annand, were evaluated at eight hemlock forests in the eastern U.S.A.
• 2 Vertical dispersal of F₁ and F₂L. nigrinus were assessed from within three crown strata (<7, 7–15 and >15 m) at four release sites.
• 3 Horizontal distributions of L. nigrinus within the forest surrounding central release areas were observed in two separate studies, which included (i) release and monitor to capture parent and F₁ movement by sampling the immature life stages of the offspring, and (ii) assessment of F₃ to F₆ generations where beetles were previously determined to be established.
• 4 Laricobius nigrinus, released on lower crown branches, oviposited within the upper crown stratum and were slow to disperse from release trees. Monitoring L. nigrinus only from the lower crown would likely underestimate its presence because 86% of the F₂ generation were detected above 15 m.
• 5 By the fifth generation, the frequency distributions of larvae increased at increasing distance from release areas; larvae were recovered at a maximum distance of approximately 400 m and the spread rate was approximately 39 m/year.
• 6 Slow dispersal of L. nigrinus and uninterrupted recovery of six generations in the presence of fluctuating prey density support its continued release as part of the A. tsugae biological control programme. These data contribute toward improved release strategies and monitoring for this biological control agent.

     

Frequent Amplification of CENPF, GMNN and CDK13 Genes in Hepatocellular Carcinomas

Genomic changes frequently occur in cancer cells during tumorigenesis from normal cells. Using the Illumina Human NS-12 single-nucleotide polymorphism (SNP) chip to screen for gene copy number changes in primary hepatocellular carcinomas (HCCs), we initially detected amplification of 35 genes from four genomic regions (1q21–41, 6p21.2–24.1, 7p13 and 8q13–23). By integrated screening of these genes for both DNA copy number and gene expression in HCC and colorectal cancer, we selected CENPF (centromere protein F/mitosin), GMNN (geminin, DNA replication inhibitor), CDK13 (cyclin-dependent kinase 13), and FAM82B (family with sequence similarity 82, member B) as common cancer genes. Each gene exhibited an amplification frequency of ∼30% (range, 20–50%) in primary HCC (n = 57) and colorectal cancer (n = 12), as well as in a panel of human cancer cell lines (n = 70). Clonogenic and invasion assays of NIH3T3 cells transfected with each of the four amplified genes showed that CENPF, GMNN, and CDK13 were highly oncogenic whereas FAM82B was not. Interestingly, the oncogenic activity of these genes (excluding FAM82B) was highly correlated with gene-copy numbers in tumor samples (correlation coefficient, r>0.423), indicating that amplifications of CENPF, GMNN, and CDK13 genes are tightly linked and coincident in tumors. Furthermore, we confirmed that CDK13 gene copy number was significantly associated with clinical onset age in patients with HCC (P = 0.0037). Taken together, our results suggest that coincidently amplified CDK13, GMNN, and CENPF genes can play a role as common cancer-driver genes in human cancers.     

Development of hydrocortisone succinic acid/and 5-fluorouracil/chitosan microcapsules for oral and topical drug deliveries

Recently, we demonstrated the safety use of calendula oil/chitosan microcapsules as a carrier for both oral and topical deliveries. We also reported the improved biological activity towards skin cells and Staphylococcus aureus of phyllanthin containing chitosan microcapsules. However, the possibility of both oral and topical applications was still necessary to be further studied. Here we investigated that both oral and topical applications of chitosan-based microcapsules were tested using hydrocortisone succinic acid (HSA) and 5-fluorouracil (5-FU), respectively. The drug loading efficiency, particle size, surface morphology and chemical compositions of both drug loaded microcapsules were confirmed by UV-vis spectrophotometer, particle size analyzer, scanning electron microscope and Fourier transform infrared spectroscopy. The in vitro release studies revealed that both HSA and 5-FU could be released form chitosan microcapsules. The mean adrenocorticotropic hormone concentration in HSA loaded microcapsule mice plasma was detected to be lower than that of water control. One hundred micrograms per milliliter of 5-FU containing microcapsules exhibited a stronger growth inhibition towards skin keratinocytes than that of free 5-FU. In vitro drug delivery model demonstrated the delivery of 5-FU from microcapsule treated textiles into nude mice skin. Further uses of the drug loaded microcapsules may provide an efficiency deliverable tool for both oral and topical applications.     

Susceptibility and response of human blood monocyte subsets to primary dengue virus infection

Human blood monocytes play a central role in dengue infections and form the majority of virus infected cells in the blood. Human blood monocytes are heterogeneous and divided into CD16(-) and CD16(+) subsets. Monocyte subsets play distinct roles during disease, but it is not currently known if monocyte subsets differentially contribute to dengue protection and pathogenesis. Here, we compared the susceptibility and response of the human CD16(-) and CD16(+) blood monocyte subsets to primary dengue virus in vitro. We found that both monocyte subsets were equally susceptible to dengue virus (DENV2 NGC), and capable of supporting the initial production of new infective virus particles. Both monocyte subsets produced anti-viral factors, including IFN-α, CXCL10 and TRAIL. However, CD16(+) monocytes were the major producers of inflammatory cytokines and chemokines in response to dengue virus, including IL-1β, TNF-α, IL-6, CCL2, 3 and 4. The susceptibility of both monocyte subsets to infection was increased after IL-4 treatment, but this increase was more profound for the CD16(+) monocyte subset, particularly at early time points after virus exposure. These findings reveal the differential role that monocyte subsets might play during dengue disease.     

Unusual long-chain N-acyl homoserine lactone production by and presence of quorum quenching activity in bacterial isolates from diseased tilapia fish

Growth-dependent cell-cell communication termed quorum sensing is a key regulatory system in bacteria for controlling gene expression including virulence factors. In this study five potential bacterial pathogens including Bacillus sp. W2.2, Klebsiella sp. W4.2, Pseudomonas sp. W3 and W3.1 and Serratia sp. W2.3 were isolated from diseased Tilapia fish in Malaysia, supplied by the leading global fish supplier. Proteolytic activity assays confirmed that with the exception of Klebsiella sp. W4.2, all isolates showed distinct proteolytic activity. Furthermore Bacillus sp. W2.2 and Pseudomonas sp. strains W3 and W3.1 also displayed haemolytic activity. By using high resolution liquid chromatography mass spectrometry, we revealed the presence of unusually long-chain N-(3-oxohexadecanoyl)-homoserine lactone (3-oxo-C16-HSL) from Pseudomonas sp. W3.1 and N-dodecanoyl-homoserine lactone (C12-HSL) from Serratia sp. W2.3, respectively. Interestingly, Pseudomonas sp. W3.1 also produced a wide range of Pseudomonas quinolone signalling (PQS) molecules. Pseudomonas sp. W3 did not show any quorum sensing properties but possessed quorum quenching activity that inactivated AHLs. This study is the first documentation that shows unusual long-chain AHLs production in Serratia sp. and Pseudomonas sp. isolated from diseased fish and the latter also produce a wide range of PQS molecules.     

Backbone resonances assignment of 19 kDa CD1 domain of human mitotic checkpoint serine/threonine-protein kinase, Bub1

Bub1 is an evolutionarily conserved mitotic checkpoint control protein that is present in diverse organisms including yeast and humans. Bub1 is a serine/threonine protein kinase and is required for recruitment of Mad1, Mad2, Bub3, and CENP-E to kinetochores (Sharp-Baker and Chen in J Cell Biol 153:1239–1250, 2001). The evolutionarily conserved amino acid region in the N-terminus has been called as the CD1 domain. To clarify the action mechanism of Bub1 in controlling check point signals, we initiated an NMR structure determination of the Bub1 CD1 domain. Here, we report the sequence-specific backbone resonance assignments of CD1 domain of human Bub1 (hBub1CD1).