New Proteolytic Pathway with Probable Hypoallergenic Properties of Lactobacillus Isolated from Dromedary Milk

Abstract The growth of several mitotic mutants of Schizosaccharomyces pombe, including nuc2-663, is inhibited by the protease inhibitor N-Tosyl-L-Phenylalanine Chloromethyl Ketone (TPCK). Because nuc2+ encodes a presumptive component of the Anaphase Promoting Complex, which is required for the ubiquitin-dependent proteolysis of certain proteins during exit from mitosis, we have used sensitivity to TPCK as a criterion by which to search for novel S. pombe mutants defective in the anaphase-promoting pathway. In a genetic screen for temperature-sensitive mitotic mutants that were also sensitive to TPCK at a permissive temperature, we isolated three tsm (TPCK-sensitive mitotic) strains. Two of these are alleles of cut1+, but tsm1-512 maps to a novel genetic location. The tsm1-512 mutation leads to delayed nuclear division at restrictive temperatures, apparently as a result of an impaired ability to form a metaphase spindle. After shift of early G2 cells to 36°, tsm1-512 arrests transiently in the second mitotic division and then exits mitosis, as judged by spindle elongation and septation. The chromosomes, however, often fail to segregate properly. Genetic interactions between tsm1-512 and components of the anaphase proteolytic pathway suggest a functional involvement of the Tsm1 protein in this pathway.

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The ubiquitin-mediated proteolytic pathway as a therapeutic area

Journal of Molecular Medicine ◽

10.1007/s001090050081 ◽

1997 ◽

Vol 75 (1) ◽

pp. 5-17 ◽

Cited By ~ 75

Author(s):

Mark Rolfe ◽

M. Isabel Chiu ◽

M. Pagano

Keyword(s):

Therapeutic Area ◽

Proteolytic Pathway

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Dromedary milk fat: thermal and structural properties 2. Influence of cooling rate

Dairy Science & Technology ◽

10.1051/lait:2005034 ◽

2005 ◽

Vol 85 (6) ◽

pp. 433-451 ◽

Cited By ~ 7

Author(s):

Nadia Karray ◽

Christelle Lopez ◽

Pierre Lesieur ◽

Michel Ollivon

Keyword(s):

Cooling Rate ◽

Structural Properties ◽

Milk Fat ◽

Dromedary Milk

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15-Lipoxygenase is a component of the mammalian sperm cytoplasmic droplet

Reproduction ◽

10.1530/rep.1.00646 ◽

2005 ◽

Vol 130 (2) ◽

pp. 213-222 ◽

Cited By ~ 37

Author(s):

K A Fischer ◽

K Van Leyen ◽

K W Lovercamp ◽

G Manandhar ◽

M Sutovsky ◽

...

Keyword(s):

Semen Quality ◽

Mammalian Species ◽

Immune Serum ◽

Residual Body ◽

Cytoplasmic Droplet ◽

Mammalian Sperm ◽

Proteolytic Pathway ◽

Cellular Debris ◽

Ubiquitin Conjugating Enzyme ◽

Boar Spermatozoa

Lipoxygenases (LOXs) are a family of enzymes capable of peroxidizing phospholipids. A member of the LOX family of enzymes, 15-LOX, participates in the degradation of mitochondria and other organelles within differentiating red blood cells, the reticulocytes. The present study provides biochemical and immunocytochemical evidence for the presence of 15-LOX in the sperm cytoplasmic droplet (CD). Testicular, epididymal and ejaculated spermatozoa were evaluated for the presence of 15-LOX using an affinity-purified immune serum raised against a synthetic peptide corresponding to the C-terminal sequence of rabbit reticulocyte 15-LOX. Western blotting revealed an appropriate single band of ~81 kDa in boar spermatozoa but not in boar seminal plasma. When ejaculated boar spermatozoa were subjected to separation on a 45/90% Percoll gradient, 15-LOX co-migrated with the immotile sperm and cellular debris/CD fractions, but not with the motile sperm fraction containing morphologically normal spermatozoa without CDs. Varied levels of 15-LOX were expressed in ejaculated sperm samples from boars with varied semen quality. By immunofluorescence, prominent 15-LOX immunoreactivity was found within the residual body in the testis and within the CDs from caput, corpus and cauda epididymal and ejaculated spermatozoa. Components of the ubiquitin-dependent proteolytic pathway, which is thought to facilitate both spermiogenesis and reticulocyte organelle degradation, were also detected in the sperm CD. These included ubiquitin, the ubiquitin-conjugating enzyme E2, the ubiquitin C-terminal hydrolase PGP 9.5, and various 20S proteasomal core subunits of the α- and β-type. The 15-LOX and various components of the ubiquitin–proteasome pathway were also detected in sperm CDs of other mammalian species, including the human, mouse, stallion and wild babirusa boar. We conclude that 15-LOX is prominently present in the mammalian sperm CD and thus may contribute to spermiogenesis, CD function or CD removal.

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Characterization of nettle leaves (Urtica dioica) as a novel source of protease for clotting dromedary milk by non-destructive methods

Colloids and Surfaces B Biointerfaces ◽

10.1016/j.colsurfb.2021.112312 ◽

2021 ◽

pp. 112312

Author(s):

Alia Bouazizi ◽

Imène Felfoul ◽

Hamadi Attia ◽

Romdhane Karoui

Keyword(s):

Urtica Dioica ◽

Dromedary Milk ◽

Non Destructive ◽

Destructive Methods

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Nitric oxide function during oxygen deprivation in physiological and stress processes

Journal of Experimental Botany ◽

10.1093/jxb/eraa442 ◽

2020 ◽

Author(s):

Isabel Manrique-Gil ◽

Inmaculada Sánchez-Vicente ◽

Isabel Torres-Quezada ◽

Oscar Lorenzo

Keyword(s):

Nitric Oxide ◽

Stress Responses ◽

Abiotic Stresses ◽

Growth And Development ◽

Energy Supply ◽

Molecular Mechanisms ◽

Environmental Cues ◽

Biotic And Abiotic Stresses ◽

Proteolytic Pathway ◽

The Impact

Abstract Plants are aerobic organisms that have evolved to maintain specific requirements for oxygen (O2), leading to a correct respiratory energy supply during growth and development. There are certain plant developmental cues and biotic or abiotic stress responses where O2 is scarce. This O2 deprivation known as hypoxia may occur in hypoxic niches of plant-specific tissues and during adverse environmental cues such as pathogen attack and flooding. In general, plants respond to hypoxia through a complex reprogramming of their molecular activities with the aim of reducing the impact of stress on their physiological and cellular homeostasis. This review focuses on the fine-tuned regulation of hypoxia triggered by a network of gaseous compounds that includes O2, ethylene, and nitric oxide. In view of recent scientific advances, we summarize the molecular mechanisms mediated by phytoglobins and by the N-degron proteolytic pathway, focusing on embryogenesis, seed imbibition, and germination, and also specific structures, most notably root apical and shoot apical meristems. In addition, those biotic and abiotic stresses that comprise hypoxia are also highlighted.

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Disruption of Heat Shock Factor 1 Reveals an Essential Role in the Ubiquitin Proteolytic Pathway

Molecular and Cellular Biology ◽

10.1128/mcb.20.8.2670-2675.2000 ◽

2000 ◽

Vol 20 (8) ◽

pp. 2670-2675 ◽

Cited By ~ 83

Author(s):

Lila Pirkkala ◽

Tero-Pekka Alastalo ◽

XiaoXia Zuo ◽

Ivor J. Benjamin ◽

Lea Sistonen

Keyword(s):

Stress Response ◽

Heat Shock ◽

Hsp70 Expression ◽

Heat Shock Factor 1 ◽

Loss Of Function ◽

Down Regulation ◽

Proteolytic Pathway ◽

Ubiquitin Proteasome ◽

A Cell ◽

Shock Proteins

ABSTRACT Inhibition of proteasome-mediated protein degradation machinery is a potent stress stimulus that causes accumulation of ubiquitinated proteins and increased expression of heat shock proteins (Hsps). Hsps play pivotal roles in homeostasis and protection in a cell, through their well-recognized properties as molecular chaperones. The inducible Hsp expression is regulated by the heat shock transcription factors (HSFs). Among mammalian HSFs, HSF1 has been shown to be important for regulation of the heat-induced stress gene expression, whereas the function of HSF2 in stress response is unclear. Recent reports have suggested that both HSF1 and HSF2 are affected during down-regulation of ubiquitin-proteasome pathway (Y. Kawazoe et al., Eur. J. Biochem. 255:356–362, 1998; A. Mathew et al., Mol. Cell. Biol. 18:5091–5098, 1998; D. Kim et al., Biochem. Biophys. Res. Commun. 254:264–268, 1999). To date, however, no unambiguous evidence has been presented as to whether a single specific HSF or multiple members of the HSF family are required for transcriptional induction of heat shock genes when proteasome activity is down-regulated. Therefore, by using loss-of-function and gain-of-function strategies, we investigated the specific roles of mammalian HSFs in regulation of the ubiquitin-proteasome-mediated stress response. Here we demonstrate that HSF1, but not HSF2, is essential and sufficient for up-regulation of Hsp70 expression during down-regulation of the ubiquitin proteolytic pathway. We propose that specificity of HSF1 could be an important therapeutic target during disease pathogenesis associated with abnormal ubiquitin-dependent proteasome function.

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The Arg/N-Degron Pathway—A Potential Running Back in Fine-Tuning the Inflammatory Response?

Biomolecules ◽

10.3390/biom10060903 ◽

2020 ◽

Vol 10 (6) ◽

pp. 903

Author(s):

Dominique Leboeuf ◽

Maxim Pyatkov ◽

Timofei S. Zatsepin ◽

Konstantin Piatkov

Keyword(s):

Inflammatory Responses ◽

Fine Tuning ◽

Protein Fragments ◽

E3 Ligases ◽

Selective Degradation ◽

Proinflammatory Mediators ◽

Proteolytic Pathway ◽

Inflammatory Processes ◽

A Cell ◽

Inflammatory Caspases

Recognition of danger signals by a cell initiates a powerful cascade of events generally leading to inflammation. Inflammatory caspases and several other proteases become activated and subsequently cleave their target proinflammatory mediators. The irreversible nature of this process implies that the newly generated proinflammatory fragments need to be sequestered, inhibited, or degraded in order to cancel the proinflammatory program or prevent chronic inflammation. The Arg/N-degron pathway is a ubiquitin-dependent proteolytic pathway that specifically degrades protein fragments bearing N-degrons, or destabilizing residues, which are recognized by the E3 ligases of the pathway. Here, we report that the Arg/N-degron pathway selectively degrades a number of proinflammatory fragments, including some activated inflammatory caspases, contributing in tuning inflammatory processes. Partial ablation of the Arg/N-degron pathway greatly increases IL-1β secretion, indicating the importance of this ubiquitous pathway in the initiation and resolution of inflammation. Thus, we propose a model wherein the Arg/N-degron pathway participates in the control of inflammation in two ways: in the generation of inflammatory signals by the degradation of inhibitory anti-inflammatory domains and as an “off switch” for inflammatory responses through the selective degradation of proinflammatory fragments.

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