Differential Regulation and Function of Glutathione Peroxidases and Other Selenoproteins

2001 ◽  
pp. 425-448
Author(s):  
Xin Gen Lei
Keyword(s):  
Differential Regulation ◽  
Glutathione Peroxidases ◽  
And Function

scholarly journals Differential Regulation of Gonadotropins as Revealed by Transcriptomes of Distinct LH and FSH Cells of Fish Pituitary

2021 ◽  
Vol 22 (12) ◽  
pp. 6478
Author(s):  
Lian Hollander-Cohen ◽  
Matan Golan ◽  
Berta Levavi-Sivan
Keyword(s):  
Follicle Stimulating Hormone ◽  
Differential Regulation ◽  
Receptor Expression ◽  
Hormone Regulation ◽  
Fish Reproduction ◽  
Cell Type ◽  
Conserved Genes ◽  
Transgenic Tilapia ◽  
And Function ◽  
Direct Regulation

From mammals to fish, reproduction is driven by luteinizing hormone (LH) and follicle-stimulating hormone (FSH) temporally secreted from the pituitary gland. Teleost fish are an excellent model for addressing the unique regulation and function of each gonadotropin cell since, unlike mammals, they synthesize and secrete LH and FSH from distinct cells. Only very distant vertebrate classes (such as fish and birds) demonstrate the mono-hormonal strategy, suggesting a potential convergent evolution. Cell-specific transcriptome analysis of double-labeled transgenic tilapia expressing GFP and RFP in LH or FSH cells, respectively, yielded genes specifically enriched in each cell type, revealing differences in hormone regulation, receptor expression, cell signaling, and electrical properties. Each cell type expresses a unique GPCR signature that reveals the direct regulation of metabolic and homeostatic hormones. Comparing these novel transcriptomes to that of rat gonadotrophs revealed conserved genes that might specifically contribute to each gonadotropin activity in mammals, suggesting conserved mechanisms controlling the differential regulation of gonadotropins in vertebrates.

scholarly journals Extracellular Signal-Regulated Kinase 1c (ERK1c), a Novel 42-Kilodalton ERK, Demonstrates Unique Modes of Regulation, Localization, and Function

2004 ◽  
Vol 24 (22) ◽  
pp. 10000-10015 ◽  
Author(s):  
Daniel M. Aebersold ◽  
Yoav D. Shaul ◽  
Yuval Yung ◽  
Nirit Yarom ◽  
Zhong Yao ◽  
...  
Keyword(s):  
Cell Density ◽  
Differential Regulation ◽  
Dominant Negative ◽  
Signaling Specificity ◽  
Cellular Processes ◽  
Extracellular Signal ◽  
Extracellular Stimuli ◽  
Golgi Fragmentation ◽  
And Function ◽  
Rats And Mice

ABSTRACT Extracellular signal-regulated kinases (ERKs) are signaling molecules that regulate many cellular processes. We have previously identified an alternatively spliced 46-kDa form of ERK1 that is expressed in rats and mice and named ERK1b. Here we report that the same splicing event in humans and monkeys causes, due to sequence differences in the inserted introns, the production of an ERK isoform that migrates together with the 42-kDa ERK2. Because of the differences of this isoform from ERK1b, we named it ERK1c. We found that its expression levels are about 10% of ERK1. ERK1c seems to be expressed in a wide variety of tissues and cells. Its activation by MEKs and inactivation by phosphatases are slower than those of ERK1, which is probably the reason for its differential regulation in response to extracellular stimuli. Unlike ERK1, ERK1c undergoes monoubiquitination, which is increased with elevated cell density concomitantly with accumulation of ERK1c in the Golgi apparatus. Elevated cell density also causes enhanced Golgi fragmentation, which is facilitated by overexpression of native ERK1c and is prevented by dominant-negative ERK1c, indicating that ERK1c mediates cell density-induced Golgi fragmentation. The differential regulation of ERK1c extends the signaling specificity of MEKs after stimulation by various extracellular stimuli.

scholarly journals Looking Back at the Early Times of Redox Biology

2020 ◽  
Author(s):  
Leopold Flohe
Keyword(s):  
Hydrogen Peroxide ◽  
Metabolic Regulation ◽  
Redox Regulation ◽  
Biological Systems ◽  
Lipid Hydroperoxide ◽  
Nitrogen Monoxide ◽  
Redox Biology ◽  
Glutathione Peroxidases ◽  
And Function ◽  
Heme Peroxidases

The beginnings of redox biology are recalled with special emphasis on formation, metabolism and function of reactive oxygen and nitrogen species in mammalian systems. The review covers the early history of heme peroxidases and the metabolism of hydrogen peroxide, the discovery of selenium as integral part of glutathione peroxidases, which expanded the scope of the field to other hydroperoxides including lipid hydroperoxide, the discovery of superoxide dismutases and superoxide radicals in biological systems and their role in host defense, tissue damage, metabolic regulation and signaling, the identification of the endothelial-derived relaxing factor as the nitrogen monoxide radical and its physiological and pathological implications. The article highlights the perception of hydrogen peroxide and other hydroperoxides as signaling molecules, which marks the beginning of the flourishing fields of redox regulation and redox signaling. Final comments describe the development of the redox language. In the 18th and 19th century, it was highly individualized and hard to translate into modern terminology. In the 20th century, the redox language co-developed with the chemical terminology and became clearer. More recently, the introduction and inflationary use of poorly defined terms has unfortunately impaired the understanding of redox events in biological systems.

scholarly journals EAR2 and EAR3/COUP-TFI Regulate Transcription of the Rat LH Receptor

2001 ◽  
Vol 15 (11) ◽  
pp. 1891-1905 ◽  
Author(s):  
Ying Zhang ◽  
Maria L. Dufau
Keyword(s):  
Granulosa Cells ◽  
Direct Repeat ◽  
Differential Regulation ◽  
Nucleotide Difference ◽  
Orphan Receptors ◽  
Lh Receptor ◽  
Protein Levels ◽  
Regulated Expression ◽  
Differential Binding ◽  
And Function

Abstract Our previous studies demonstrated regulation of the human LH receptor (hLHR) promoter by nuclear orphan receptors EAR2, EAR3/COUP-TFI (repression), and TR4 (activation) through a direct-repeat motif (hDR). The current studies investigated the differential binding of orphan receptors to rat (rLHR) and hLHR promoters, and their modulation of rLHR gene transcription in rat granulosa cells. The rLHR DR with one nucleotide difference from hDR at its core sequence mediated inhibition of the rLHR transcription, to which EAR2 and EAR3/COUP-TFI but not TR4 bound. The A/C mismatch was responsible for the lack of TR4 binding and function, but had no effect on EAR2 and EAR3/COUP-TFI. EAR2 and EAR3/COUP-TF bound to the rLHR DR with lower affinity than to the hDR, and exhibited lesser inhibitory capacity. This difference resulted from the lack of a guanine in the rDR, which is present 3′ next to the hDR core. These studies have identified sequence-specific requirements for the binding of EAR2, EAR3/COUP-TFI, and TR4 to the DRs that explain their differential regulation of rat and human LHR genes. In addition, hCG treatment significantly reduced the inhibition of rLHR gene in granulosa cells and also decreased EAR2 and EAR3/COUP-TFI protein levels. These results indicate that hormonally regulated expression of EAR2 and EAR3/COUP-TFI contributes to gonadotropin-induced derepression of LHR promoter activity in granulosa cells.

scholarly journals Differential Regulation and Function of Fas Expression on Glial Cells

2000 ◽  
Vol 164 (3) ◽  
pp. 1277-1285 ◽  
Author(s):  
Sung Joong Lee ◽  
Tong Zhou ◽  
Chulhee Choi ◽  
Zheng Wang ◽  
Etty N. Benveniste
Keyword(s):  
Glial Cells ◽  
Differential Regulation ◽  
And Function
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