scholarly journals Endoplasmic reticulum membrane-bound MoSec62 is involved in the suppression of rice immunity and is essential for the pathogenicity ofMagnaporthe oryzae

2016 ◽  
Vol 17 (8) ◽  
pp. 1211-1222 ◽  
Author(s):  
Zhuangzhi Zhou ◽  
Zhiqian Pang ◽  
Guihua Li ◽  
Chunhua Lin ◽  
Jing Wang ◽  
...  
Keyword(s):  
Endoplasmic Reticulum ◽  
Endoplasmic Reticulum Membrane ◽  
Membrane Bound

scholarly journals The Conserved Npl4 Protein Complex Mediates Proteasome-dependent Membrane-bound Transcription Factor Activation

2001 ◽  
Vol 12 (10) ◽  
pp. 3226-3241 ◽  
Author(s):  
Amy L. Hitchcock ◽  
Heike Krebber ◽  
Seth Frietze ◽  
Andrew Lin ◽  
Martin Latterich ◽  
...  
Keyword(s):  
Endoplasmic Reticulum ◽  
Transcription Factors ◽  
Regulation Of Gene Expression ◽  
Fatty Acid Desaturase ◽  
Endoplasmic Reticulum Membrane ◽  
Desaturase Gene ◽  
Proteolytic Activation ◽  
Transcription Factor Activation ◽  
Membrane Bound ◽  
Fatty Acid Desaturase Gene

Proteolytic activation of membrane-bound transcription factors has emerged as an important mechanism for the regulation of gene expression. Two membrane-bound transcription factors regulated in this manner are the Saccharomyces cerevisiae proteins Mga2p and Spt23p, which direct transcription of the Δ9-fatty acid desaturase gene OLE1. We now show that a membrane-associated complex containing the highly conserved Npl4p, Ufd1p, and Cdc48p proteins mediates the proteasome-regulated cleavage of Mga2p and Spt23p. Mutations in NPL4,UFD1, and CDC48 cause a block in Mga2p and Spt23p processing, with concomitant loss of OLE1expression. Taken together, our data indicate that the Npl4 complex may serve to target the proteasome to the ubiquitinated endoplasmic reticulum membrane-bound proteins Mga2p and Spt23p. Given the recent finding that NPL4 is allelic to the ERAD geneHRD4, we further propose that this NPL4function extends to all endoplasmic reticulum-membrane–associated targets of the proteasome.

scholarly journals A comparative study of ribonuclease hydrolysis of rat brain-cortex and liver membrane-bound ribosomes

1973 ◽  
Vol 135 (2) ◽  
pp. 299-305 ◽  
Author(s):  
H. Simpkins ◽  
E. Panko ◽  
S. Tay
Keyword(s):  
Endoplasmic Reticulum ◽  
Ribosomal Rna ◽  
Brain Cortex ◽  
Polyacrylamide Gel Electrophoresis ◽  
Endoplasmic Reticulum Membrane ◽  
Low Concentrations ◽  
Liver Membrane ◽  
Membrane Bound ◽  
Hydrolysis Of ◽  
Brain Ribosomes

Because it has been proposed that the ribosome–membrane interaction is different in endoplasmic reticulum derived from a non-secretory and secretory cell we undertook a study to determine whether attachment of the ribosome to the membrane involved ribosomal RNA and if the rRNA in ribosomes derived from the two classes of cell possessed an altered susceptibility to RNAase (ribonuclease) hydrolysis. We found that brain ribosomes appeared to possess more regions accessible to nuclease attack, independent of whether a sequence-dependent RNAase (T1) or a sterically hindered RNAase bound to Enzite polymer was employed. These results were independent of whether the ribosomes were membrane-bound or detached from the endoplasmic reticulum membranes, but at high RNAase concentration these differences became negligible. No conclusions, however, could be drawn as to whether ribosomal RNA is involved in the attachment of the ribosome to the endoplasmic reticulum membrane, because of the presence of endogeneous membrane-associated RNAases. Analysis of the rRNA fragments by polyacrylamide-gel electrophoresis suggests that the sites available for attack by low concentrations of nuclease in bound-ribosomes derived from brain cortex are different from those of liver.

Effects of Compatible Solutes on Mammalian Cytochrome P450 Stability

1997 ◽  
Vol 52 (1-2) ◽  
pp. 132-136 ◽  
Author(s):  
W. Nikolaus Kühn-Velten
Keyword(s):  
Endoplasmic Reticulum ◽  
Cytochrome P450 ◽  
Compatible Solutes ◽  
Compatible Solute ◽  
Heat Denaturation ◽  
Endoplasmic Reticulum Membrane ◽  
Protective Effects ◽  
Spectral Transition ◽  
Membrane Bound

AbstractThe sensitivity of pig cytochrome P450cl7 (CYP17), an endoplasmic reticulum membrane-bound enzyme, towards heat denaturation (48 °C) was measured by the P450-to-P420 spectral transition indicating conforma­tional labilization of the protein. Both sucrose and glucose have comparable and increasingly protective effects at concentrations ranging from 100 to 800 mм, while ectoine, a novel zwitterionic compatible solute which regulates bacterial osmoadaptation and stabilizes cytoplasmic enzymes, has a strong labilizing effect on CYP17 and favours its proteolytic inactivation possibly by electrostatic derangements. Sucrose or glucose, but not ectoine, can therefore eventually be proposed as compatible stabilizers of cytochrome P450 structures.

Analysis of the Anterior Secretory Cells of Onchidohs Muricata (Nudibranchia)

1981 ◽  
Vol 39 ◽  
pp. 614-615
Author(s):  
Roy Skidmore
Keyword(s):  
Endoplasmic Reticulum ◽  
Secretory Granules ◽  
Golgi Body ◽  
The Body ◽  
Secretory Cells ◽  
Secretory Vesicles ◽  
High Magnification ◽  
Large Numbers ◽  
Membrane Bound ◽  
Sole Of The Foot

The long-necked secretory cells in Onchidoris muricata are distributed in the anterior sole of the foot. These cells are interspersed among ciliated columnar and conical cells as well as short-necked secretory gland cells. The long-necked cells contribute a significant amount of mucoid materials to the slime on which the nudibranch travels. The body of these cells is found in the subepidermal tissues. A long process extends across the basal lamina and in between cells of the epidermis to the surface of the foot. The secretory granules travel along the process and their contents are expelled by exocytosis at the foot surface.The contents of the cell body include the nucleus, some endoplasmic reticulum, and an extensive Golgi body with large numbers of secretory vesicles (Fig. 1). The secretory vesicles are membrane bound and contain a fibrillar matrix. At high magnification the similarity of the contents in the Golgi saccules and the secretory vesicles becomes apparent (Fig. 2).

The ultrastructure of the double membrane-bound bodies and endoplasmic reticulum in serial sections of wheat spot mosaic-affected wheat plants

1990 ◽  
Vol 48 (3) ◽  
pp. 694-695
Author(s):  
M. H. Chen ◽  
C. Hiruki
Keyword(s):  
Endoplasmic Reticulum ◽  
High Resolution ◽  
Membrane Structure ◽  
Mosaic Disease ◽  
Serial Sections ◽  
Thin Sections ◽  
Double Membrane ◽  
Southern Alberta ◽  
Membrane Bound ◽  
Scanning Em

Wheat spot mosaic disease was first discovered in southern Alberta, Canada, in 1956. A hitherto unidentified disease-causing agent, transmitted by the eriophyid mite, caused chlorosis, stunting and finally severe necrosis resulting in the death of the affected plants. Double membrane-bound bodies (DMBB), 0.1-0.2 μm in diameter were found to be associated with the disease.Young tissues of leaf and root from 4-wk-old infected wheat plants were fixed, dehydrated, and embedded in Spurr’s resin. Serial sections were collected on slot copper grids and stained. The thin sections were then examined with a Hitachi H-7000 TEM at 75 kV. The membrane structure of the DMBBs was studied by numbering them individually and tracing along the sections to see any physical connection with endoplasmic reticulum (ER) membranes. For high resolution scanning EM, a modification of Tanaka’s method was used. The specimens were examined with a Hitachi Model S-570 SEM in its high resolution mode at 20 kV.

scholarly journals Alternative redox forms of ASNA-1 separate insulin signaling from tail-anchored protein targeting and cisplatin resistance in C. elegans

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Dorota Raj ◽  
Ola Billing ◽  
Agnieszka Podraza-Farhanieh ◽  
Bashar Kraish ◽  
Oskar Hemmingsson ◽  
...  
Keyword(s):  
Endoplasmic Reticulum ◽  
Insulin Secretion ◽  
Protein Targeting ◽  
Cisplatin Resistance ◽  
Acquired Resistance ◽  
Endoplasmic Reticulum Membrane ◽  
C Elegans ◽  
Cisplatin Sensitivity ◽  
Tumor Environment ◽  
The One

AbstractCisplatin is a frontline cancer therapeutic, but intrinsic or acquired resistance is common. We previously showed that cisplatin sensitivity can be achieved by inactivation of ASNA-1/TRC40 in mammalian cancer cells and in Caenorhabditis elegans. ASNA-1 has two more conserved functions: in promoting tail-anchored protein (TAP) targeting to the endoplasmic reticulum membrane and in promoting insulin secretion. However, the relation between its different functions has remained unknown. Here, we show that ASNA-1 exists in two redox states that promote TAP-targeting and insulin secretion separately. The reduced state is the one required for cisplatin resistance: an ASNA-1 point mutant, in which the protein preferentially was found in the oxidized state, was sensitive to cisplatin and defective for TAP targeting but had no insulin secretion defect. The same was true for mutants in wrb-1, which we identify as the C. elegans homolog of WRB, the ASNA1/TRC40 receptor. Finally, we uncover a previously unknown action of cisplatin induced reactive oxygen species: cisplatin induced ROS drives ASNA-1 into the oxidized form, and selectively prevents an ASNA-1-dependent TAP substrate from reaching the endoplasmic reticulum. Our work suggests that ASNA-1 acts as a redox-sensitive target for cisplatin cytotoxicity and that cisplatin resistance is likely mediated by ASNA-1-dependent TAP substrates. Treatments that promote an oxidizing tumor environment should be explored as possible means to combat cisplatin resistance.

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