scholarly journals The Cellular Localization of the p42 and p46 Oligoadenylate Synthetase 1 Isoforms and Their Impact on Mitochondrial Respiration

Viruses ◽  
2019 ◽  
Vol 11 (12) ◽  
pp. 1122 ◽  
Author(s):  
Stig Skrivergaard ◽  
Monica Skou Jensen ◽  
Tine Breckling Rolander ◽  
Tram Bao Ngoc Nguyen ◽  
Amanda Bundgaard ◽  
...  
Keyword(s):  
High Resolution ◽  
Fluorescence Microscopy ◽  
Cellular Localization ◽  
Immunoblot Analysis ◽  
Rnase L ◽  
Oligoadenylate Synthetase ◽  
Innate Response ◽  
Viral Pathogens ◽  
The Difference ◽  
Caax Motif

The importance of the IFN-induced oligoadenylate synthetase (OAS) proteins and the OAS/RNase L pathway in the innate response against viral pathogens is well-established, however the observed differences in anti-viral activity between the human OAS1 p46 and p42 isoforms are not fully understood. The protein expression of these isoforms is determined by the SNP rs10774671, either being an A or a G allele resulting in expression of either the p42 or the p46 isoform. Using fluorescence microscopy and immunoblot analysis of fractionated cell samples, we show here that the CaaX motif is of key importance to the cellular localization. The OAS1 p42 isoform is mainly located in the cytosol, whereas the p46 isoform with a C-terminal CaaX motif is translocated to membranous organelles, like the mitochondria. We furthermore observed differences between p42 and p46 in their effect on mitochondrial physiology using high resolution respirometry and fluorometry. Overexpression of OAS1 p42 and IFN-β treatment of HeLa cells (AA genotype) resulted in significantly increased respiration, which was not seen with p46 overexpression. The difference in subcellular localization and mitochondrial effect of these two OAS1 isoforms might help to explain the anti-viral mechanisms that differentiate these proteins.

scholarly journals RNase L Induces Expression of A Novel Serine/Threonine Protein Kinase, DRAK1, to Promote Apoptosis

2019 ◽  
Vol 20 (14) ◽  
pp. 3535 ◽  
Author(s):  
Praveen Manivannan ◽  
Vidita Reddy ◽  
Sushovita Mukherjee ◽  
Kirsten Neytania Clark ◽  
Krishnamurthy Malathi
Keyword(s):  
Protein Kinase ◽  
Signaling Pathway ◽  
Cellular Localization ◽  
Caspase 3 ◽  
Parp Inhibitors ◽  
Rnase L ◽  
Oligoadenylate Synthetase ◽  
Cytochrome C Release ◽  
Interferon Induction ◽  
Death Associated Protein Kinase

Apoptosis of virus-infected cells is an effective antiviral mechanism in addition to interferon induction to establish antiviral state to restrict virus spread. The interferon-inducible 2′–5′ oligoadenylate synthetase/RNase L pathway results in activation of RNase L in response to double stranded RNA and cleaves diverse RNA substrates to amplify interferon induction and promote apoptosis. Here we show that RNase L induces expression of Death-associated protein kinase-Related Apoptosis-inducing protein Kinase 1 (DRAK1), a member of the death-associated protein kinase family and interferon-signaling pathway is required for induction. Overexpression of DRAK1 triggers apoptosis in the absence of RNase L activation by activating c-Jun N-terminal kinase (JNK), translocation of BCL2 Associated X (Bax) to the mitochondria accompanied by cytochrome C release and loss of mitochondrial membrane potential promoting cleavage of caspase 3 and Poly(ADP-Ribose) Polymerase 1 (PARP). Inhibitors of JNK and caspase 3 promote survival of DRAK1 overexpressing cells demonstrating an important role of JNK signaling pathway in DRAK1-mediated apoptosis. DRAK1 mutant proteins that lack kinase activity or nuclear localization fail to induce apoptosis highlighting the importance of cellular localization and kinase function in promoting cell death. Our studies identify DRAK1 as a mediator of RNase L-induced apoptosis.

Origin of the alternate bright/dark contrast in HREM images of hexagonal crystals, particularly 6H-SiC

1993 ◽  
Vol 51 ◽  
pp. 914-915
Author(s):  
J.S. Bow ◽  
R.W. Carpenter ◽  
M.J. Kim
Keyword(s):  
High Resolution ◽  
Incident Beam ◽  
Hexagonal Crystal ◽  
Detailed Explanation ◽  
Similar Character ◽  
High Resolution Images ◽  
The Difference ◽  
Zigzag Shape ◽  
Hexagonal Crystals ◽  
Dark Contrast

A prominent characteristic of high-resolution images of 6H-SiC viewed from [110] is a zigzag shape with a period of 6 layers as shown in Fig.1. Sometimes the contrast is same through the 6 layers of (0006) planes (Fig.1a), but in most cases it appears as in Fig.1b -- alternate bright/dark contrast among every three (0006) planes. Alternate bright/dark contrast is most common for the thicker specimens. The SAD patterns of these two types of image are almost same, and there is no indication that the difference results from compositional ordering. O’Keefe et al. concluded this type of alternate contrast was due to crystal tilt in thick parts of the specimen. However, no detailed explanation was given. Images of similar character from Ti3Al, which is also a hexagonal crystal, were reported by Howe et al. Howe attributed the bright/dark contrast among alternate (0002) Ti3Al planes to phase shifts produced by incident beam tilt.

scholarly journals Fast high-resolution 3D total internal reflection fluorescence microscopy by incidence angle scanning and azimuthal averaging

2014 ◽  
Vol 111 (48) ◽  
pp. 17164-17169 ◽  
Author(s):  
Jérôme Boulanger ◽  
Charles Gueudry ◽  
Daniel Münch ◽  
Bertrand Cinquin ◽  
Perrine Paul-Gilloteaux ◽  
...  
Keyword(s):  
High Resolution ◽  
Fluorescence Microscopy ◽  
Total Internal Reflection ◽  
Incidence Angle ◽  
Internal Reflection ◽  
Total Internal Reflection Fluorescence

Array design

1968 ◽  
Vol 58 (3) ◽  
pp. 977-991
Author(s):  
Richard A. Haubrich
Keyword(s):  
High Resolution ◽  
Data Processing ◽  
Least Square ◽  
Wave Number ◽  
Array Design ◽  
Least Square Fit ◽  
The Difference ◽  
Set Of Points ◽  
Array Output

abstract Arrays of detectors placed at discrete points are often used in problems requiring high resolution in wave number for a limited number of detectors. The resolution performance of an array depends on the positions of detectors as well as the data processing of the array output. The performance can be expressed in terms of the “spectrum window”. Spectrum windows may be designed by a general least-square fit procedure. An alternate approach is to design the array to obtain the largest uniformly spaced coarray, the set of points which includes all the difference spacings of the array. Some designs obtained from the two methods are given and compared.

Confocal fluorescence microscopy with the tandem scanning light microscope

1989 ◽  
Vol 94 (4) ◽  
pp. 617-624
Author(s):  
S.J. Wright ◽  
J.S. Walker ◽  
H. Schatten ◽  
C. Simerly ◽  
J.J. McCarthy ◽  
...  
Keyword(s):  
High Resolution ◽  
Fluorescence Microscopy ◽  
Light Microscope ◽  
Three Dimensional ◽  
Three Dimensions ◽  
Complex Structures ◽  
Charge Coupled Device ◽  
Confocal Fluorescence ◽  
Cooled Ccd ◽  
Cellular Components

Applications of the tandem scanning confocal microscope (TSM) to fluorescence microscopy and its ability to resolve fluorescent biological structures are described. The TSM, in conjunction with a cooled charge-coupled device (cooled CCD) and conventional epifluorescence light source and filter sets, provided high-resolution, confocal data, so that different fluorescent cellular components were distinguished in three dimensions within the same cell. One of the unique features of the TSM is the ability to image fluorochromes excited by ultraviolet light (e.g. Hoechst, DAPI) in addition to fluorescein and rhodamine. Since the illumination is dim, photobleaching is insignificant and prolonged viewing of living specimens is possible. Series of optical sections taken in the Z-axis with the TSM were reproduced as stereo images and three-dimensional reconstructions. These data show that the TSM is potentially a powerful tool in fluorescence microscopy for determining three-dimensional relationships of complex structures within cells labeled with multiple fluorochromes.

scholarly journals Photoactivatable mCherry for high-resolution two-color fluorescence microscopy

2009 ◽  
Vol 6 (2) ◽  
pp. 153-159 ◽  
Author(s):  
Fedor V Subach ◽  
George H Patterson ◽  
Suliana Manley ◽  
Jennifer M Gillette ◽  
Jennifer Lippincott-Schwartz ◽  
...  
Keyword(s):  
High Resolution ◽  
Fluorescence Microscopy
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