Differential expression of fatty acid hydroxylase domain-containing 2 in human epithelial ovarian cancer.

Epithelial ovarian cancer (EOC) is the most lethal gynecologic cancer (1). We performed discovery of genes associated with epithelial ovarian cancer and of the high-grade serous ovarian cancer (HGSC) subtype, using published microarray data (2, 3) to compare global gene expression profiles of normal ovary or fallopian tube with that of primary tumors from women diagnosed with epithelial ovarian cancer or HGSC. We identified the gene encoding fatty acid hydroxylase domain-containing 2, FAXDC2, as among the genes whose expression was most different in epithelial ovarian cancer as compared to the normal fallopian tube. FAXDC2 expression was significantly lower in high-grade serous ovarian tumors relative to normal fallopian tube. FAXDC2 expression correlated with progression-free survival in patients with ovarian cancer. These data indicate that expression of FAXDC2 is perturbed in epithelial ovarian cancers broadly and in ovarian cancers of the HGSC subtype. FAXDC2 may be relevant to pathways underlying ovarian cancer initiation (transformation) or progression.

ENGANANDO O CITOCROMO P450BM3: CATÁLISE DE VÁRIAS TRANSFORMAÇÕES DE SUBSTRATOS NÃO NATIVOS USANDO MOLÉCULAS-TRAIÇOEIRAS

TRICKING CYTOCHROME P450BM3: CATALYSIS OF VARIOUS NON-NATIVE SUBSTRATE TRANSFORMATIONS USING DECOY MOLECULES. In order to accomplish a greener chemistry, enzymes, such as the fatty-acid hydroxylase cytochrome P450BM3, have garnered increasing attention as potential candidates for the development of potent biocatalysts in recent years. However, one of the biggest issues hampering the quick and efficient application of P450BM3 as a biocatalyst lies in its stringent substrate specificity. Consequently, diverse mutagenesis-based approaches have been successfully employed as a means to alter the substrate specificity of P450BM3, leading to the generation of a myriad of highly specialised mutant variants. Nevertheless, repeated exhaustive mutagenesis is a laborious process with no guarantee for success, thus, alternative methods to more easily alter the enzyme’s substrate specificity have become increasingly desirable. In recent years, decoy molecules, which possess the ability to deceive wild-type P450BM3 into hydroxylating a range of non-native substrates, have emerged as such a “simpler” alternative. Within this review, focus will be placed upon the process underlying the development of these decoy molecules, which will be discussed in great detail. Furthermore, a summary of recent developments pertaining to the potential applications of decoy molecules from the development of a whole-cell biocatalyst to their use in crystallography will be discussed.

LeTetR Positively Regulates 3-Hydroxylation of the Antifungal HSAF and Its Analogs in Lysobacter enzymogenes OH11

The biocontrol agent Lysobacter enzymogenes OH11 produces several structurally distinct antibiotic compounds, including the antifungal HSAF (Heat Stable Antifungal Factor) and alteramides, along with their 3-dehydroxyl precursors (3-deOH). We previously showed that the 3-hydroxylation is the final step of the biosynthesis and is also a key structural moiety for the antifungal activity. However, the procedure through which OH11 regulates the 3-hydroxylation is still not clear. In OH11, the gene orf3232 was predicted to encode a TetR regulator (LeTetR) with unknown function. Here, we deleted orf3232 and found that the LeTetR mutant produced very little HSAF and alteramides, while the 3-deOH compounds were not significantly affected. The production of HSAF and alteramides was restored in orf3232-complemented mutant. qRT-PCR showed that the deletion of orf3232 impaired the transcription of a putative fatty acid hydroxylase gene, orf2195, but did not directly affect the expression of the HSAF biosynthetic gene cluster (hsaf). When an enzyme extract from E. coli expressing the fatty acid hydroxylase gene, hsaf-orf7, was added to the LeTetR mutant, the production of HSAF and alteramides increased by 13–14 fold. This study revealed a rare function of the TetR family regulator, which positively controls the final step of the antifungal biosynthesis and thus controls the antifungal activity of the biocontrol agent.

noeM, a New Nodulation Gene Involved in the Biosynthesis of Nod Factors with an Open-Chain Oxidized Terminal Residue and in the Symbiosis with Mimosa pudica

The β-rhizobium Cupriavidus taiwanensis is a nitrogen-fixing symbiont of Mimosa pudica. Nod factors produced by this species were previously found to be pentameric chitin-oligomers carrying common C18:1 or C16:0 fatty acyl chains, N-methylated and C-6 carbamoylated on the nonreducing terminal N-acetylglucosamine and sulfated on the reducing terminal residue. Here, we report that, in addition, C. taiwanensis LMG19424 produces molecules where the reducing sugar is open and oxidized. We identified a novel nodulation gene located on the symbiotic plasmid pRalta, called noeM, which is involved in this atypical Nod factor structure. noeM encodes a transmembrane protein bearing a fatty acid hydroxylase domain. This gene is expressed during symbiosis with M. pudica and requires NodD and luteolin for optimal expression. The closest noeM homologs formed a separate phylogenetic clade containing rhizobial genes only, which are located on symbiosis plasmids downstream from a nod box. Corresponding proteins, referred to as NoeM, may have specialized in symbiosis via the connection to the nodulation pathway and the spread in rhizobia. noeM was mostly found in isolates of the Mimoseae tribe, and specifically detected in all tested strains able to nodulate M. pudica. A noeM deletion mutant of C. taiwanensis was affected for the nodulation of M. pudica, confirming the role of noeM in the symbiosis with this legume.

A diagnostic approach for neurodegeneration with brain iron accumulation: clinical features, genetics and brain imaging

ABSTRACT Neurodegeneration with brain iron accumulation (NBIA) represents a heterogeneous and complex group of inherited neurodegenerative diseases, characterized by excessive iron accumulation, particularly in the basal ganglia. Common clinical features of NBIA include movement disorders, particularly parkinsonism and dystonia, cognitive dysfunction, pyramidal signs, and retinal abnormalities. The forms of NBIA described to date include pantothenase kinase-associated neurodegeneration (PKAN), phospholipase A2 associated neurodegeneration (PLAN), neuroferritinopathy, aceruloplasminemia, beta-propeller protein-associated neurodegeneration (BPAN), Kufor-Rakeb syndrome, mitochondrial membrane protein-associated neurodegeneration (MPAN), fatty acid hydroxylase-associated neurodegeneration (FAHN), coenzyme A synthase protein-associated neurodegeneration (CoPAN) and Woodhouse-Sakati syndrome. This review is a diagnostic approach for NBIA cases, from clinical features and brain imaging findings to the genetic etiology.