A lipoxygenase with dual positional specificity is expressed in olives (Olea europaea L.) during ripening.

International audiencePlant lipoxygenases (LOXs) are a class of widespread dioxygenases catalysing the hydroperoxidation of polyunsaturated fatty acids. Although multiple isoforms of LOX have been detected in a wide range of plants, their physiological roles remain to be clarified. With the aim to clarify the occurrence of LOXs in olives and their contribution to the elaboration of the olive oil aroma, we cloned and characterized the first cDNA of the LOX isoform which is expressed during olive development. The open reading frame encodes a polypeptide of 864 amino acids. This olive LOX is a type-1 LOX which shows a high degree of identity at the peptide level towards hazelnut (77.3%), tobacco (76.3%) and almond (75.5%) LOXs. The recombinant enzyme shows a dual positional specificity, as it forms both 9- and 13-hydroperoxide of linoleic acid in a 2:1 ratio, and would be defined as 9/13-LOX. Although a LOX activity was detected throughout the olive development, the 9/13-LOX is mainly expressed at late developmental stages. Our data suggest that there are at least two Lox genes expressed in black olives, and that the 9/13-LOX is associated with the ripening and senescence processes. However, due to its dual positional specificity and its expression pattern, its contribution to the elaboration of the olive oil aroma might be considered

Systematic Gene Overexpression in Candida albicans identifies a Regulator of Early Adaptation to the Mammalian Gut

We are grateful to members of the genomics core facility (PF2, Génopole) for the availability of the microarray scanner and the Alain Jacquier’s lab for making the GenePix software available. We are grateful to Drs. Suzanne Noble and Aaron Mitchell for providing C. albicans mutant collections. We thank all members of the Fungal Biology & Pathogenicity Unit, particularly Drs. Anne Neville and Adeline Feri for their numerous insights during the course of this project. This work has been supported by grants from the Agence Nationale de la Recherche (KANJI, ANR-08-MIE-033-01 to C.d’E. and F.D.; ERA-Net Infect-ERA, FUNCOMPATH, ANR-14-IFEC-0004; and CANDIHUB, ANR-14-CE-0018 to C.d’E.), the French Government’s Investissement d’Avenir program (Laboratoire d’Excellence Integrative Biology of Emerging Infectious Diseases, ANR-10-LABX-62-IBEID to C.d’E.; Institut de Recherche Technologique BIOASTER, ANR-10-AIRT-03 to C.d’E., F.D. and T.J.), the European Commission (FinSysB PITN-GA-2008-214004 to C.d’E.) and the Wellcome Trust (The Candida albicans ORFeome project, WT088858MA to C.d’E. and C.M.). C.M. acknowledges support from the Medical Research Council, UK (New Investigator Award, G0400284), the MRC Centre for Medical Mycology (MR/N006364/1) and the University of Aberdeen. S.Z. is an Institut Pasteur International Network Affiliate Program Fellow. S.Z., L.v.W. and A.H.C. were the recipients of post-doctoral fellowships from the European Commission (FINSysB, PITN-GA-2008-214004 to S.Z.), the Agence Nationale de la Recherche (KANJI, ANR-08-MIE-033-01 to S.Z.; ERA-Net Infect-ERA, FUNCOMPATH, ANR-14-IFEC-0004 to A.H.C.; CANDIHUB, ANR-14-CE-0018 to L.v.W) and the French Government’s Investissement d’Avenir program (Institut de Recherche Technologique BIOASTER, ANR-10-AIRT-03 to S.Z. and A.H.C.). The funders had no role in study design, data collection and analysis, decision to publish, or preparation of the manuscript.Peer reviewedPublisher PD

Reproducibility of Heart Rate Variability Indices in Children with Cystic Fibrosis

Fundamental to the potential utilisation of heart rate variability (HRV) indices as a prognostic tool is the reproducibility of these measures. The purpose of the present study was therefore to investigate the reproducibility of 24-hour derived HRV indices in a clinical paediatric population. Eighteen children (10 boys; 12.4 ± 2.8 years) with mild to moderate Cystic Fibrosis (CF; FVC: 83 ± 12% predicted; FEV1: 80 ± 9% predicted) and eighteen age- and sex-matched controls (10 boys; 12.5 ± 2.7 years) wore a combined ECG and accelerometer for two consecutive days. Standard time and frequency domain indices of HRV were subsequently derived. Reproducibility was assessed by Bland-Altman plots, 95% limits of agreement and intra-class correlation coefficients (ICC). In both groups, there was no systematic difference between days, with the variables demonstrating a symmetrical, homoscedastic distribution around the zero line. The time domain parameters demonstrated a good to excellent reproducibility irrespective of the population considered (ICC: 0.56 to 0.86). In contrast, whilst the frequency domain parameters similarly showed excellent reproducibility in the healthy children (ICC: 0.70 to 0.96), the majority of the frequency domain parameters illustrated a poor to moderate reproducibility in those with CF (ICC: 0.22 to 0.43). The exceptions to this trend were the normalised LF and HF components which were associated with a good to excellent reproducibility. These findings thereby support the utilisation of time and relative frequency domain HRV indices as a prognostic tool in children with CF. Furthermore, the present results highlight the excellent reproducibility of HRV in healthy children, indicating that this may be a useful tool to assess intervention effectiveness in this population

Mucin CYS domains are ancient and highly conserved modules that evolved in concert.

International audienceBackground : Many large secreted gel-forming mucins contain multiple copies of a "naked" cysteine-enriched domain (CYS domain) that interrupt or are adjacent to mucin domains (Ser/Thr/Pro regions). There is less similarity of homologous CYS sequences between species than there is across CYS repeats within species. These CYS domains are likely implicated in reversible mucin-mucin interactions that play a central role in mucus properties. Results : The use of multiple genome sequences in a comparative analysis of CYS sequences identified new mucins containing the CYS domain in various species. Furthermore, analysis showed that this domain is at least 650 million-year old and that CYS sequences evolved under strong selective pressure in concerted fashion in all species examined by two mechanisms that never coexist within a given gene: either multiplication of exons encoding CYS modules or successive intra-exonic duplications. Conclusion : The CYS sequences appear to have undergone concerted evolution with a high selective pressure to conserve cysteine and other amino acid residues. This domain is the best-conserved domain in secreted mucins pointing toward an important common function in many different organisms

Le défaut de mucus intestinal, nouvelle cible thérapeutique

Agents pathogènes, pH acide de l’estomac, agressions physiques et chimiques... Le mucus est la première barrière entre la lumière intestinale et les cellules de l’hôte. Ce filtre semi-perméable indispensable est constitué majoritairement d’eau et de mucines gélifiantes. De récents travaux ont montré qu’il est possible de renforcer ce mucus, qui est altéré dans de nombreuses pathologies digestives, en augmentant les interactions entre ses mucines. Ces résultats ouvrent de nouvelles pistes de recherche contre les maladies inflammatoires chroniques de l’intestin (MICI) et d’autres pathologies des muqueuses sécrétoires

Characterization of mouse muc6 and evidence of conservation of the gel-forming mucin gene cluster between human and mouse.

International audienceUsing degenerate primers designed from conserved cysteine-rich domains of gel-forming mucins, we cloned two new mouse mucin cDNAs. Blast searching showed that they belong to the same new gene assigned to chromosome 7 band F5. This gene is clustered with the three secreted large gel-forming mucins Muc2, Muc5ac, and Muc5b in a region that exhibits synteny with human chromosome 11p15. Computer analysis and sequence alignments with mucin genes predict that the new gene is composed of 33 exons and spans 30 kb from the initiation ATG codon to the Stop codon. Sequence similarities, domain organization of the deduced peptide, and expression analysis allow us to conclude that this newly cloned mouse gene is Muc6, i.e., the mouse ortholog of human MUC6. Like those of their human homologs, the genomic order and arrangement of the four mucins within the cluster of mucin genes are conserved

Organisation du gène de mucine humaine MUC5B et bases moléculaires d’une nouvelle classification des gènes de mucines

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Organisation du gène de mucine humaine MUC5B et bases moléculaires d’une nouvelle classification des gènes de mucines

International audienc

Organisation du gène de mucine humaine MUC5B et bases moléculaires d’une nouvelle classification des gènes de mucines

International audienc