Identification of salivary mucin MUC7 binding proteins from Streptococcus gordonii

<p>Abstract</p> <p>Background</p> <p>The salivary mucin MUC7 (previously known as MG2) can adhere to various strains of streptococci that are primary colonizers and predominant microorganisms of the oral cavity. Although there is a growing interest in interaction between oral pathogens and salivary mucins, studies reporting the specific binding sites on the bacteria are rather limited. Identification and characterization of the specific interacting proteins on the bacterial cell surface, termed adhesins, are crucial to further understand host-pathogen interactions.</p> <p>Results</p> <p>We demonstrate here, using purified MUC7 to overlay blots of SDS-extracts of <it>Streptococcus gordonii </it>cell surface proteins, 4 MUC7-binding bands, with apparent molecular masses of 62, 78, 84 and 133 kDa from the <it>Streptococcus gordonii </it>strain, PK488. Putative adhesins were identified by in-gel digestion and subsequent nanoLC-tandem mass spectrometry analysis of resultant peptides. The 62 kDa and 84 kDa bands were identified as elongation factor (EF) Tu and EF-G respectively. The 78 kDa band was a <it>hppA </it>gene product; the 74 kDa oligopeptide-binding lipoprotein. The 133 kDa band contained two proteins; alpha enolase and DNA-directed RNA polymerase, beta' subunit. Some of these proteins, for example alpha enolase are expected to be intracellular, however, flow cytometric analysis confirmed its location on the bacterial surface.</p> <p>Conclusion</p> <p>Our data demonstrated that <it>S. gordonii </it>expressed a number of putative MUC7 recognizing proteins and these contribute to MUC7 mucin binding of this streptococcal strain.</p

S-wave splitting in the offshore South Island, New Zealand : insights into plate-boundary deformation

Author Posting. © American Geophysical Union, 2015. This article is posted here by permission of American Geophysical Union for personal use, not for redistribution. The definitive version was published in Geochemistry, Geophysics, Geosystems 16 (2015): 2829–2847, doi:10.1002/2015GC005882.Local and regional S-wave splitting in the offshore South Island of the New Zealand plate-boundary zone provides constraints on the spatial and depth extent of the anisotropic structure with an enhanced resolution relative to land-based and SKS studies. The combined analysis of offshore and land measurements using splitting tomography suggests plate-boundary shear dominates in the central and northern South Island. The width of this shear zone in the central South Island is about 200 km, but is complicated by stress-controlled anisotropy at shallow levels. In northern South Island, a broader (>200 km) zone of plate-boundary parallel anisotropy is associated with the transitional faulting between the Alpine fault and Hikurangi subduction and the Hikurangi subduction zone itself. These results suggest S-phases of deep events (∼90 km) in the central South Island are sensitive to plate-boundary derived NE-SW aligned anisotropic media in the upper-lithosphere, supporting a “thin viscous sheet” deformation model.United States National Ocean Bottom Seismograph Instrumentation Pool2016-02-2

Upper mantle seismic anisotropy at a strike-slip boundary: South Island, New Zealand

New shear wave splitting measurements made from stations onshore and offshore the South Island of New Zealand show a zone of anisotropy 100–200 km wide. Measurements in central South Island and up to approximately 100 km offshore from the west coast yield orientations of the fast quasi-shear wave nearly parallel to relative plate motion, with increased obliquity to this orientation observed farther from shore. On the eastern side of the island, fast orientations rotate counterclockwise to become nearly perpendicular to the orientation of relative plate motion approximately 200 km off the east coast. Uniform delay times between the fast and slow quasi-shear waves of nearly 2.0 s onshore continue to stations approximately 100 km off the west coast, after which they decrease to ~1 s at 200 km. Stations more than ~300 km from the west coast show little to no splitting. East coast stations have delay times around 1 s. Simple strain fields calculated from a thin viscous sheet model (representing distributed lithospheric deformation) with strain rates decreasing exponentially to both the northwest and southeast with e-folding dimensions of 25–35 km (approximately 75% of the deformation within a zone 100–140 km wide) match orientations and amounts of observed splitting. A model of deformation localized in the lithosphere and then spreading out in the asthenosphere also yields predictions consistent with observed splitting if, at depths of 100–130 km below the lithosphere, typical grain sizes are ~ 6–7 mm.New Zealand. Ministry of Research, Science, and TechnologyNational Science Foundation (U.S.). Continental Dynamics Program (Grant EAR-0409564)National Science Foundation (U.S.). Continental Dynamics Program (Grant EAR-0409609)National Science Foundation (U.S.). Continental Dynamics Program (Grant EAR-0409835

Constraining the Chemical Signatures and the Outburst Mechanism of the Class 0 Protostar HOPS 383

We present observations toward HOPS 383, the first known outbursting Class 0 protostar located within the Orion molecular cloud using ALMA, VLA, and SMA. The SMA observations reveal envelope scale continuum and molecular line emission surrounding HOPS 383 at 0.85 mm, 1.1 mm, and 1.3 mm. The images show that HCO$^+$ and H$^{13}$CO$^+$ peaks on or near the continuum, while N$_2$H$^+$ is reduced at the same position. This reflects the underlying chemistry where CO evaporating close to the protostar destroys N$_2$H$^+$ while forming HCO$^+$. We also observe the molecular outflow traced by $^{12}$CO ($J = 2 \rightarrow 1$) and ($J = 3 \rightarrow 2$). A disk is resolved in the ALMA 0.87 mm dust continuum, orthogonal to the outflow direction, with an apparent radius of $\sim$62 AU. Radiative transfer modeling of the continuum gives disk masses of 0.02 M$_{\odot}$ when fit to the ALMA visibilities. The models including VLA 8 mm data indicate that the disk mass could be up to a factor of 10 larger due to lower dust opacity at longer wavelengths. The disk temperature and surface density profiles from the modeling, and an assumed protostar mass of 0.5 M$_{\odot}$ suggest that the Toomre $Q$ parameter $< 1$ before the outburst, making gravitational instability a viable mechanism to explain outbursts at an early age if the disk is sufficiently massive.Comment: Accepted by Ap

Mapping the Protein Domain Structures of the Respiratory Mucins: A Mucin Proteome Coverage Study

Mucin genes encode a family of the largest expressed proteins in the human genome. The proteins are highly substituted with O-linked oligosaccharides which greatly restrict access to the peptide backbones. The genomic organization of the N-terminal, O-glycosylated, and C-terminal regions of most of the mucins has been established and is available in the sequence databases. However, much less is known about the fate of their exposed protein regions after translation and secretion, and, to date, detailed proteomic studies complementary to the genomic studies are rather limited. Using mucins isolated from cultured human airway epithelial cell secretions, trypsin digestion and mass spectrometry, we investigated the proteome coverage of the mucins responsible for the maintenance and protection of the airway epithelia. Excluding the heavily glycosylated mucin domains, up to 85% coverage of the N-terminal region of the gel forming mucins MUC5B and MUC5AC was achieved, and up to 60% of the C-terminal regions were covered, suggesting that more N- and sparsely O-glycosylated regions as well as possible other modifications are available at the C-terminus. All possible peptides from the cysteine-rich regions that interrupt the heavily glycosylated mucin domains were identified. Interestingly, 43 cleavage sites from ten different domains of MUC5B and MUC5AC were identified, which possessed a non-tryptic cleavage site on the N-terminal end of the peptide, indicating potential exposure to proteolytic and/or “spontaneous cleavages”. Some of these non-tryptic cleavages may be important for proper maturation of the molecule, before and/or after secretion. Most of the peptides identified from MUC16 were from the SEA region. Surprisingly, three peptides were clearly identified from its heavily glycosylated regions. Up to 25% coverage of MUC4 was achieved covering seven different domains of the molecule. All peptides from the MUC1 cytoplasmic domain were detected along with the three non-tryptic cleavages in the region. Only one peptide was identified from MUC20 which led us to successful antisera raised against the molecule. Taken together, this report represents our current efforts to dissect the complexities of mucin macromolecules. Identification of regions accessible to proteolysis can help in the design of effective antibodies and points to regions that might be available for mucin-protein interactions and identification of cleavage sites will enable understanding of their pre- and post-secretory processing in normal and disease environments

Kinematic Analysis of a Protostellar Multiple System: Measuring the Protostar Masses and Assessing Gravitational Instability in the Disks of L1448 IRS3B and L1448 IRS3A

We present new Atacama Large Millimeter/submillimeter Array (ALMA) observations towards a compact (230~au separation) triple protostar system, L1448 IRS3B, at 879~\micron with \contbeam~resolution. Spiral arm structure within the circum-multiple disk is well resolved in dust continuum toward IRS3B, and we detect the known wide (2300~au) companion, IRS3A, also resolving possible spiral substructure. Using dense gas tracers, C17O, H13CO$+$, and H13CN, we resolve the Keplerian rotation for both the circum-triple disk in IRS3B and the disk around IRS3A. Furthermore, we use the molecular line kinematic data and radiative transfer modeling of the molecular line emission to confirm that the disks are in Keplerian rotation with fitted masses of $1.19^{+0.13}_{-0.07}$ for IRS3B-ab, $1.51^{+0.06}_{-0.07}$~Msun for IRS3A, and place an upper limit on the central protostar mass for the tertiary IRS3B-c of 0.2~Msun. We measure the mass of the fragmenting disk of IRS3B to be 0.29~Msun from the dust continuum emission of the circum-multiple disk and estimate the mass of the clump surrounding IRS3B-c to be 0.07~Msun. We also find that the disk around IRS3A has a mass of 0.04~Msun. By analyzing the Toomre~Q parameter, we find the IRS3A circumstellar disk is gravitationally stable (Q$>$5), while the IRS3B disk is consistent with a gravitationally unstable disk (Q$<$1) between the radii 200-500~au. This coincides with the location of the spiral arms and the tertiary companion IRS3B-c, supporting the hypothesis that IRS3B-c was formed in situ via fragmentation of a gravitationally unstable disk