Ontogenesis of the hpi axis and molecular regulation of the cortisol stress response during early development in dicentrarchus labrax

Contains fulltext : 133141.pdf (publisher's version ) (Open Access

Knockout of the hsd11b2 gene extends the cortisol stress response in both zebrafish larvae and adults

The Hsd11b2 enzyme converts cortisol into its inactive form, cortisone and regulates cortisol levels, in particular in response to stress. Taking advantage of CRISPR/Cas9 technology, we generated a hsd11b2 zebrafish mutant line to evaluate the involvement of this gene in stress response regulation. The absence of a functional Hsd11b2 affects survival of zebrafish, although homozygous hsd11b2−/− mutants can reach adulthood. Reproductive capability of hsd11b2−/− homozygous adult males is almost completely abrogated, while that of females is reduced. Interestingly, basal cortisol levels and glucocorticoid-dependent transcriptional activities are not affected by the mutation. In agreement with basal cortisol results, we also demonstrated that basal response to light (LMR-L/D) or mechanical (VSRA) stimuli is not significantly different in wild-type (hsd11b2+/+) compared to mutant larvae. However, after exposure to an acute stressor, the cortisol temporal patterns of synthesis and release are prolonged in both 5 days post fertilization larvae and one-year-old adult hsd11b2−/− zebrafish compared to wild-type siblings, showing at the same time, at 5 dpf, a higher magnitude in the stress response at 10 min post stress. All in all, this new zebrafish model represents a good tool for studying response to different stressors and to identify mechanisms that are induced by cortisol during stress response

Alpha-MSH and melanocortin receptors at early ontogeny in European sea bass (Dicentrarchus labrax, L.)

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Purification, crystallization and preliminary X-ray analysis of the peptidoglycan N-acetylglucosamine deacetylase BC1960 from Bacillus cereus in the presence of its substrate (GlcNAc)6

The peptidoglycan N-acetylglucosamine (GlcNAc) deacetylase BC1960 from Bacillus cereus (EC 3.5.1.33), an enzyme consisting of 275 amino acids, was crystallized in the presence of its substrate (GlcNAc)(6). The crystals belonged to the tetragonal space group P4(1)2(1)2, with unit-cell parameters a = b = 92.7, c = 242.9 A and four molecules in the asymmetric unit. A complete data set was collected at 100 K to a resolution of 2.38 A using synchrotron radiation

Purification, crystallization and preliminary X-ray analysis of the peptidoglycan N-acetylglucosamine deacetylase BC1960 from Bacillus cereus in the presence of its substrate (GlcNAc)6

The peptidoglycan N-acetylglucosamine (GlcNAc) deacetylase BC1960 from Bacillus cereus (EC 3.5.1.33), an enzyme consisting of 275 amino acids, was crystallized in the presence of its substrate (GlcNAc)(6). The crystals belonged to the tetragonal space group P4(1)2(1)2, with unit-cell parameters a = b = 92.7, c = 242.9 A and four molecules in the asymmetric unit. A complete data set was collected at 100 K to a resolution of 2.38 A using synchrotron radiation

Randia cochinchinensis Merrill

原著和名: ミサヲノキ科名: アカネ科 = Rubiaceae採集地: 三重県 尾鷲市 九鬼 (紀伊 尾鷲市 九鬼)採集日: 1963/6/2採集者: 萩庭丈壽整理番号: JH029874国立科学博物館整理番号: TNS-VS-97987

Unusual α-Carbon Hydroxylation of Proline Promotes Active-Site Maturation

The full extent of proline (Pro) hydroxylation has yet to be established, as it is largely unexplored in bacteria. We describe here a so far unknown Pro hydroxylation activity which occurs in active sites of polysaccharide deacetylases (PDAs) from bacterial pathogens, modifying the protein backbone at the C_α atom of a Pro residue to produce 2-hydroxyproline (2-Hyp). This process modifies with high specificity a conserved Pro, shares with the deacetylation reaction the same active site and one catalytic residue, and utilizes molecular oxygen as source for the hydroxyl group oxygen of 2-Hyp. By providing additional hydrogen-bonding capacity, the Pro→2-Hyp conversion alters the active site and enhances significantly deacetylase activity, probably by creating a more favorable environment for transition-state stabilization. Our results classify this process as an active-site “maturation”, which is highly atypical in being a protein backbone-modifying activity, rather than a side-chain-modifying one