Key Role of Fe2+in Epithiospecifier Protein Activity

2010 ◽  
Vol 58 (15) ◽  
pp. 8512-8521 ◽  
Author(s):  
David J. Williams ◽  
Christa Critchley ◽  
Sharon Pun ◽  
Mridusmita Chaliha ◽  
Timothy J. O’Hare
Keyword(s):  
Protein Activity ◽  
Epithiospecifier Protein

scholarly journals Molecular Genetic Evidence for the Role of SGT1 in the Intramolecular Complementation of Bs2 Protein Activity in Nicotiana benthamiana

2005 ◽  
Vol 17 (4) ◽  
pp. 1268-1278 ◽  
Author(s):  
R. Todd Leister ◽  
Douglas Dahlbeck ◽  
Brad Day ◽  
Yi Li ◽  
Olga Chesnokova ◽  
...  
Keyword(s):  
Nicotiana Benthamiana ◽  
Molecular Genetic ◽  
Genetic Evidence ◽  
Protein Activity ◽  
Molecular Genetic Evidence

scholarly journals Coupled scRNA-Seq and Intracellular Protein Activity Reveal an Immunosuppressive Role of TREM2 in Cancer

Cell ◽  
2020 ◽  
Vol 182 (4) ◽  
pp. 872-885.e19 ◽  
Author(s):  
Yonatan Katzenelenbogen ◽  
Fadi Sheban ◽  
Adam Yalin ◽  
Ido Yofe ◽  
Dmitry Svetlichnyy ◽  
...  
Keyword(s):  
Intracellular Protein ◽  
Protein Activity

Structural chemistry involved in information detection and transmission by gas sensor heme proteins: Resonance Raman investigation

2008 ◽  
Vol 80 (12) ◽  
pp. 2667-2678 ◽  
Author(s):  
Samir F. El-Mashtoly ◽  
Teizo Kitagawa
Keyword(s):  
Gas Sensor ◽  
Structural Changes ◽  
Catalytic Domain ◽  
Signal Transmission ◽  
Resonance Raman ◽  
Protein Activity ◽  
Sensor Proteins ◽  
Vinyl Group ◽  
Protein Moiety

A variety of heme-containing gas sensor proteins have been discovered by gene analysis from bacteria to mammals. In general, these proteins are composed of an N-terminal heme-containing sensor domain and a C-terminal catalytic domain. Binding of O2, CO, or NO to the heme causes a change in the structure of heme, which alters the protein conformation in the vicinity of the heme, and the conformational change is propagated to the catalytic domain, leading to regulation of the protein activity. This mini-review summarizes the recent resonance Raman studies obtained with both visible and UV excitation sources for two O2 sensor proteins, EcDOS and HemAT-Bs. These investigations have shown the role of heme propionate hydrogen-bonding interactions in communicating the heme structural changes, which occur upon ligand binding, from heme to the protein moiety. Furthermore, it is deduced that the contact interactions between the heme 2-vinyl group and the surrounding residues are also important for signal transmission from heme to protein in EcDOS.

scholarly journals Emerging roles of non-coding RNAs in vector-borne infections

2020 ◽  
Vol 134 (5) ◽  
pp. jcs246744
Author(s):  
Chaima Bensaoud ◽  
Larissa Almeida Martins ◽  
Hajer Aounallah ◽  
Michael Hackenberg ◽  
Michail Kotsyfakis
Keyword(s):  
Protein Activity ◽  
Arthropod Vector ◽  
Vector Borne Diseases ◽  
Defense Systems ◽  
Sequencing Studies ◽  
Vector Borne ◽  
Vertebrate Hosts ◽  
Non Coding Rnas ◽  
Eukaryotic Genomes

ABSTRACTNon-coding RNAs (ncRNAs) are nucleotide sequences that are known to assume regulatory roles previously thought to be reserved for proteins. Their functions include the regulation of protein activity and localization and the organization of subcellular structures. Sequencing studies have now identified thousands of ncRNAs encoded within the prokaryotic and eukaryotic genomes, leading to advances in several fields including parasitology. ncRNAs play major roles in several aspects of vector–host–pathogen interactions. Arthropod vector ncRNAs are secreted through extracellular vesicles into vertebrate hosts to counteract host defense systems and ensure arthropod survival. Conversely, hosts can use specific ncRNAs as one of several strategies to overcome arthropod vector invasion. In addition, pathogens transmitted through vector saliva into vertebrate hosts also possess ncRNAs thought to contribute to their pathogenicity. Recent studies have addressed ncRNAs in vectors or vertebrate hosts, with relatively few studies investigating the role of ncRNAs derived from pathogens and their involvement in establishing infections, especially in the context of vector-borne diseases. This Review summarizes recent data focusing on pathogen-derived ncRNAs and their role in modulating the cellular responses that favor pathogen survival in the vertebrate host and the arthropod vector, as well as host ncRNAs that interact with vector-borne pathogens.

Mitochondrial SIRT5 is present in follicular cells and is altered by reduced ovarian reserve and advanced maternal age

2014 ◽  
Vol 26 (8) ◽  
pp. 1072 ◽  
Author(s):  
Leanne Pacella-Ince ◽  
Deirdre L. Zander-Fox ◽  
Michelle Lane
Keyword(s):  
Follicular Fluid ◽  
Ovarian Reserve ◽  
Protein Function ◽  
Maternal Age ◽  
Cumulus Cells ◽  
Advanced Maternal Age ◽  
Oocyte Quality ◽  
Carbamoyl Phosphate ◽  
Protein Activity

Women with reduced ovarian reserve or advanced maternal age have an altered metabolic follicular microenvironment. As sirtuin 5 (SIRT5) senses cellular metabolic state and post-translationally alters protein function, its activity may directly impact on oocyte viability and pregnancy outcome. Therefore, we investigated the role of SIRT5 in relation to ovarian reserve and maternal age. Women (n = 47) undergoing routine IVF treatment were recruited and allocated to one of three cohorts based on ovarian reserve and maternal age. Surplus follicular fluid, granulosa and cumulus cells were collected. SIRT5 mRNA, protein and protein activity was confirmed in granulosa and cumulus cells via qPCR, immunohistochemistry, western blotting and desuccinylation activity. The presence of carbamoyl phosphate synthase I (CPS1), a target of SIRT5, was investigated by immunohistochemistry and follicular-fluid ammonium concentrations determined via microfluorometry. Women with reduced ovarian reserve or advanced maternal age had decreased SIRT5 mRNA, protein and desuccinylation activity in granulosa and cumulus cells resulting in an accumulation of follicular-fluid ammonium, presumably via alterations in activity of a SIRT5 target, CPS1, which was present in granulosa and cumulus cells. This suggests a role for SIRT5 in influencing oocyte quality and IVF outcomes.

scholarly journals SCL Assembles a Multifactorial Complex That Determines Glycophorin A Expression

2004 ◽  
Vol 24 (4) ◽  
pp. 1439-1452 ◽  
Author(s):  
Rachid Lahlil ◽  
Eric Lécuyer ◽  
Sabine Herblot ◽  
Trang Hoang
Keyword(s):  
Transcription Factors ◽  
Hematopoietic Cells ◽  
Inhibitory Effect ◽  
Erythroid Cell ◽  
Glycophorin A ◽  
Protein Activity ◽  
Protein Levels ◽  
Helix Loop Helix

ABSTRACT SCL/TAL1 is a hematopoietic-specific transcription factor of the basic helix-loop-helix (bHLH) family that is essential for erythropoiesis. Here we identify the erythroid cell-specific glycophorin A gene (GPA) as a target of SCL in primary hematopoietic cells and show that SCL occupies the GPA locus in vivo. GPA promoter activation is dependent on the assembly of a multifactorial complex containing SCL as well as ubiquitous (E47, Sp1, and Ldb1) and tissue-specific (LMO2 and GATA-1) transcription factors. In addition, our observations suggest functional specialization within this complex, as SCL provides its HLH protein interaction motif, GATA-1 exerts a DNA-tethering function through its binding to a critical GATA element in the GPA promoter, and E47 requires its N-terminal moiety (most likely entailing a transactivation function). Finally, endogenous GPA expression is disrupted in hematopoietic cells through the dominant-inhibitory effect of a truncated form of E47 (E47-bHLH) on E-protein activity or of FOG (Friend of GATA) on GATA activity or when LMO2 or Ldb-1 protein levels are decreased. Together, these observations reveal the functional complementarities of transcription factors within the SCL complex and the essential role of SCL as a nucleation factor within a higher-order complex required to activate gene GPA expression.

scholarly journals Uncoupling proteins in mitochondria of plants and some microorganisms.

2001 ◽  
Vol 48 (1) ◽  
pp. 145-155 ◽  
Author(s):  
W Jarmuszkiewicz
Keyword(s):  
Higher Plants ◽  
Uncoupling Protein ◽  
Physiological Role ◽  
Acanthamoeba Castellanii ◽  
Uncoupling Proteins ◽  
Protein Activity ◽  
Functional Connection ◽  
Mitochondrial Inner Membrane ◽  
Mitochondrial Carrier Family

Uncoupling proteins, members of the mitochondrial carrier family, are present in mitochondrial inner membrane and mediate free fatty acid-activated, purine-nucleotide-inhibited H+ re-uptake. Since 1995, it has been shown that the uncoupling protein is present in many higher plants and some microorganisms like non-photosynthetic amoeboid protozoon, Acanthamoeba castellanii and non-fermentative yeast Candida parapsilosis. In mitochondria of these organisms, uncoupling protein activity is revealed not only by stimulation of state 4 respiration by free fatty acids accompanied by decrease in membrane potential (these effects being partially released by ATP and GTP) but mainly by lowering ADP/O ratio during state 3 respiration. Plant and microorganism uncoupling proteins are able to divert very efficiently energy from oxidative phosphorylation, competing for deltamicroH+ with ATP synthase. Functional connection and physiological role of uncoupling protein and alternative oxidase, two main energy-dissipating systems in plant-type mitochondria, are discussed.

scholarly journals Analysis of the Role of N-glycosylation in Cell-surface expression, Function and Binding Properties of SARS-CoV-2 receptor ACE2

2021 ◽  
Author(s):  
Alberto Brandariz-Nuñez ◽  
Raymond R Rowland
Keyword(s):  
Cell Surface ◽  
Viral Entry ◽  
Biological Activities ◽  
Surface Expression ◽  
Cell Surface Expression ◽  
Type I ◽  
Protein Activity ◽  
Host Cell Membrane ◽  
S Protein

Human angiotensin I-converting enzyme 2 (hACE2) is a type-I transmembrane glycoprotein that serves as the major cell entry receptor for SARS-CoV and SARS-CoV-2. The viral spike (S) protein is required for attachment to ACE2 and subsequent virus-host cell membrane fusion. Previous work has demonstrated the presence of N-linked glycans in ACE2. N-glycosylation is implicated in many biological activities, including protein folding, protein activity, and cell surface expression of biomolecules. However, the contribution of N-glycosylation to ACE2 function is poorly understood. Here, we examined the role of N-glycosylation in the activity and localization of two species with different susceptibility to SARS-CoV-2 infection, porcine ACE2 (pACE2) and hACE2. The elimination of N-glycosylation by tunicamycin (TM) treatment or mutagenesis, showed that N-glycosylation is critical for the proper cell surface expression of ACE2 but not for its carboxiprotease activity. Furthermore, nonglycosylable ACE2 localized predominantly in the endoplasmic reticulum (ER) and not at the cell surface. Our data also revealed that binding of SARS-CoV and SARS-CoV-2 S protein to porcine or human ACE2 was not affected by deglycosylation of ACE2 or S proteins, suggesting that N-glycosylation plays no role in the interaction between SARS coronaviruses and the ACE2 receptor. Impairment of hACE2 N-glycosylation decreased cell to cell fusion mediated by SARS-CoV S protein but not SARS-CoV-2 S protein. Finally, we found that hACE2 N-glycosylation is required for an efficient viral entry of SARS-CoV/SARS-CoV-2 S pseudotyped viruses, which could be the result of low cell surface expression of the deglycosylated ACE2 receptor.

The Role of Sulfates on Antifreeze Protein Activity

2014 ◽  
Vol 118 (28) ◽  
pp. 7920-7924 ◽  
Author(s):  
Konrad Meister ◽  
John G. Duman ◽  
Yao Xu ◽  
Arthur L. DeVries ◽  
David M. Leitner ◽  
...  
Keyword(s):  
Antifreeze Protein ◽  
Protein Activity
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