Search results for "Apparatu"
showing 10 items of 195 documents
Out for a Walk Along the Secretory Pathway During Programmed Cell Death
2015
This chapter provides a comprehensive updated analysis on the role of the secretory pathway in the orchestration of cell’s demise, an emerging and promising research topic in the field of plant programmed cell death (PCD). Since my first review on this topic, a plethora of data has been published supporting the concept that endomembrane system-forming subcellular compartments cooperate to coordinate cellular responses to developmental and environmental cues and thereby can dictate a cell’s ultimate fate. Thus, the early secretory pathway, encompassing the endoplasmic reticulum and Golgi apparatus, can be involved in the perception of extrinsic and intrinsic stimuli. It can also be an active…
Death of mitochondria during programmed cell death of leaf mesophyll cells
2005
The role of plant mitochondria in the programmed cell death (PCD) is widely discussed. However, spectrum and sequence of mitochondrial structural changes during different types of PCD in leaves are poorly described. Pea, cucumber and rye plants were grown under controlled growing conditions. A part of them were sprinkled with ethylene releaser to accelerate cell death. During yellowing the palisade parenchyma mitochondria were attracted to nuclear envelope. Mitochondrial matrix became electron translucent. Mitochondria entered vacuole by invagination of tonoplast and formed multivesicular bodies. Ethephon treatment increased the frequency of sticking of mitochondria to the nuclear envelope …
The N-glycan processing in HT-29 cells is a function of their state of enterocytic differentiation. Evidence for an atypical traffic associated with …
1991
International audience; When the human colon cancer cells HT-29 undergo enterocytic differentiation, they correctly process their N-glycans, whereas their undifferentiated counterpart are unable to process Man9-8-GlcNAc2 species, the natural substrate of alpha-mannosidase I. As this enzyme is fully active in both HT-29 cell populations, we hypothesize that N-glycoproteins are unable to reach the cis Golgi, the site where alpha-mannosidase I has been localized. We have demonstrated this point by using 1-deoxymannojirimycin, leupeptin, and monensin. In the presence of 1-deoxymannojirimycin, a specific inhibitor of alpha-mannosidase I, differentiated HT-29 cells, as expected, accumulate Man9-8…
Missense mutations of dual oxidase 2 (DUOX2) implicated in congenital hypothyroidism have impaired trafficking in cells reconstituted with DUOX2 matu…
2007
Abstract Dual oxidase 2 (DUOX2), a reduced NAD phosphate:O2 oxidoreductase flavoprotein, is a component of the thyrocyte H2O2 generator required for hormone synthesis at the apical plasma membrane. We recently identified a specific DUOX2 maturation factor (DUOXA2) that is necessary and sufficient for expression of functional DUOX2 in mammalian cell lines. We have now used a DUOXA2 reconstituted system to provide the first characterization of natural DUOX2 missense variants (Q36H, R376W, D506N) at the molecular level, analyzing their impact on H2O2 generation, trafficking, stability, folding, and DUOXA2 interaction. The Q36H and R376W mutations completely prevent routing of DUOX2 to the cell…
Dithiothreitol Treatment of Madin-Darby Canine Kidney Cells Reversibly Blocks Export from the Endoplasmic Reticulum but Does Not Affect Vectorial Tar…
1995
Addition of dithiothreitol (DTT) to the culture medium of Madin-Darby canine kidney (MDCK) cells blocks transport of newly synthesized gp80 (clusterin, apolipoprotein J), a soluble marker protein for apical exocytosis in this epithelial cell line. In cells treated with DTT during pulse labeling, gp80 is retained in the endoplasmic reticulum. After removal of the reducing agent, gp80 is posttranslationally oxidized and secreted at the apical surface of MDCK cell monolayers. This demonstrates that when folded and oxidized posttranslationally, gp80 can acquire a conformation that exhibits sorting signals for vectorial targeting. In the continuous presence of DTT, the transepithelial electrical…
Phylogenetic profiling and cellular analyses of ARL16 reveal roles in traffic of IFT140 and INPP5E
2021
ABSTRACTThe ARF family of regulatory GTPases is ancient, with 16 members predicted to have been present in the last eukaryotic common ancestor. Our phylogenetic profiling of paralogs in diverse species identified four family members whose presence correlates with that of a cilium/flagellum: ARL3, ARL6, ARL13, and ARL16. No prior evidence links ARL16 to cilia or other cell functions, despite its presence throughout eukaryotes. Deletion of ARL16 in MEFs results in decreased ciliogenesis yet increased ciliary length. We also found Arl16 KO in MEFs to alter ciliary protein content, including loss of ARL13B, ARL3, INPP5E, and the IFT-A core component IFT140. Instead, both INPP5E and IFT140 accum…
Identification of Trans-Golgi Network Proteins in Arabidopsis thaliana Root Tissue
2014
Knowledge of protein subcellular localization assists in the elucidation of protein function and understanding of different biological mechanisms that occur at discrete subcellular niches. Organelle-centric proteomics enables localization of thousands of proteins simultaneously. Although such techniques have successfully allowed organelle protein catalogues to be achieved, they rely on the purification or significant enrichment of the organelle of interest, which is not achievable for many organelles. Incomplete separation of organelles leads to false discoveries, with erroneous assignments. Proteomics methods that measure the distribution patterns of specific organelle markers along densit…
Beyond The Ignorant Schoolmaster : On Education, Marxism, and Psychoanalysis
2016
This first chapter introduces the main concepts of Marxist sociology and Freudian psychoanalysis, two theories that have been intensely devoted to investigating and overcoming the epistemological effects caused by the phenomenal forms which inhered in the mode of production and the psychic apparatus, their respective subject matters. Their two prominent spearheads, Karl Marx and Sigmund Freud, soon understood that their scientific endeavors depended on deciphering the mechanisms which, in each case, generated these distorted reflections. These mechanisms were class division—the complex network that in any given social milieu consolidates around specific relations of production—and the split…
A novel radiation exposure control apparatus for microwave assisted chemical reactions
2004
AbstractA radiation exposure control apparatus is used for microwave (2.45 GHz) treatment of chemical reactions in controlled and reproducible conditions. A spectrophotometer has been interfaced with the microwave set-up in order to monitor the reaction evolution in situ. Both numerical and experimental dosimetries are carried out in order to evaluate the field distribution within the sample. Finally, particular working conditions are suggested.
Arabidopsis p24δ5 and p24δ9 facilitate Coat Protein I-dependent transport of the K/HDEL receptor ERD2 from the Golgi to the endoplasmic reticulum.
2014
The p24 proteins belong to a family of type I membrane proteins which cycle between the endoplasmic reticulum (ER) and Golgi via coat protein I (COPI) and COPII vesicles. Current nomenclature classifies them into four subfamilies, although plant p24 proteins belong to either the p24β or the p24δ subfamilies. Here, we show that Arabidopsis p24δ5/δ9 and HDEL ligands shift the steady-state distribution of the K/HDEL receptor ERD2 from the Golgi to the ER. We also show that p24δ5/δ9 interact directly with ERD2. This interaction requires the Golgi dynamics (GOLD) domain in p24δ5 and is much higher at acidic than at neutral pH, consistent with both proteins interacting at the cis-Golgi. In additi…