Fatty acids are essential components of biological membranes, important for the maintenance of cellular structures, especially in organisms with complex life cycles like protozoan parasites. Apicomplexans are obligate parasites responsible for various deadly diseases of humans and livestock. We analyzed the fatty acids produced by the closest phototrophic relatives of parasitic apicomplexans, the chromerids Chromera velia and Vitrella brassicaformis, and investigated the genes coding for enzymes involved in fatty acids biosynthesis in chromerids, in comparison to their parasitic relatives. Based on evidence from genomic and metabolomic data, we propose a model of fatty acid synthesis in chromerids: the plastid-localized FAS-II pathway is responsible for the de novo synthesis of fatty acids reaching the maximum length of 18 carbon units. Short saturated fatty acids (C14:0-C18:0) originate from the plastid are then elongated and desaturated in the cytosol and the endoplasmic reticulum. We identified giant FAS I-like multi-modular enzymes in both chromerids, which seem to be involved in polyketide synthesis and fatty acid elongation. This full-scale description of the biosynthesis of fatty acids and their derivatives provides important insights into the reductive evolutionary transition of a phototropic algal ancestor to obligate parasites.

• Klíčová slova
• Chromera velia, Vitrella brassicaformis, de novo biosynthesis, desaturation, elongation, evolution, fatty acids,
• MeSH
• Apicomplexa klasifikace   genetika   metabolismus   MeSH
• biosyntetické dráhy genetika   MeSH
• desaturasy mastných kyselin klasifikace   genetika   metabolismus   MeSH
• druhová specificita MeSH
• elongasy mastných kyselin klasifikace   genetika   metabolismus   MeSH
• fylogeneze MeSH
• lidé MeSH
• mastné kyseliny biosyntéza   MeSH
• molekulární evoluce MeSH
• protozoální infekce parazitologie   MeSH
• protozoální proteiny klasifikace   genetika   metabolismus   MeSH
• synthasa mastných kyselin, typ 2 klasifikace   genetika   metabolismus   MeSH
• synthasa mastných kyselin, typ I klasifikace   genetika   metabolismus   MeSH
• zvířata MeSH
• Check Tag
• lidé MeSH
• zvířata MeSH
• Publikační typ
• časopisecké články MeSH
• práce podpořená grantem MeSH
• Názvy látek
• desaturasy mastných kyselin MeSH
• elongasy mastných kyselin MeSH
• mastné kyseliny MeSH
• protozoální proteiny MeSH
• synthasa mastných kyselin, typ 2 MeSH
• synthasa mastných kyselin, typ I MeSH

Males of the closely related species Bombus terrestris and Bombus lucorum attract conspecific females by completely different marking pheromones. MP of B. terrestris and B. lucorum pheromones contain mainly isoprenoid (ISP) compounds and fatty acid derivatives, respectively. Here, we studied the regulation of ISP biosynthesis in both bumblebees. RNA-seq and qRT-PCR analyses indicated that acetoacetyl-CoA thiolase (AACT), 3-hydroxy-3-methylglutaryl-CoA reductase (HMGR), and farnesyl diphosphate synthase (FPPS) transcripts are abundant in the B. terrestris labial gland. Maximal abundance of these transcripts correlated well with AACT enzymatic activity detected in the LG extracts. In contrast, transcript abundances of AACT, HMGR, and FPPS in B. lucorum were low, and AACT activity was not detected in LGs. These results suggest that transcriptional regulation plays a key role in the control of ISP biosynthetic gene expression and ISP pheromone biosynthesis in bumblebee males.

• Klíčová slova
• Bombus spp., biosynthesis, gene expression, isoprenoids, pheromones, transcriptional regulation,
• MeSH
• feromony biosyntéza   chemie   MeSH
• hmyzí proteiny genetika   metabolismus   MeSH
• kontigové mapování MeSH
• regulace genové exprese MeSH
• RNA chemie   izolace a purifikace   metabolismus   MeSH
• sekvenční analýza RNA MeSH
• terpeny chemie   metabolismus   MeSH
• včely chemie   genetika   metabolismus   MeSH
• zvířata MeSH
• Check Tag
• mužské pohlaví MeSH
• ženské pohlaví MeSH
• zvířata MeSH
• Publikační typ
• časopisecké články MeSH
• práce podpořená grantem MeSH
• Názvy látek
• feromony MeSH
• hmyzí proteiny MeSH
• RNA MeSH
• terpeny MeSH

In natural environments, photosynthetic organisms adjust their metabolism to cope with the fluctuating availability of combined nitrogen sources, a growth-limiting factor. For acclimation, the dynamic degradation/synthesis of tetrapyrrolic pigments, as well as of the amino acid arginine, is pivotal; however, there has been no evidence that these processes could be functionally coupled. Using co-immunopurification and spectral shift assays, we found that in the cyanobacterium Synechocystis sp. PCC 6803, the arginine metabolism-related ArgD and CphB enzymes form protein complexes with Gun4, an essential protein for chlorophyll biosynthesis. Gun4 binds ArgD with high affinity, and the Gun4-ArgD complex accumulates in cells supplemented with ornithine, a key intermediate of the arginine pathway. Elevated ornithine levels restricted de novo synthesis of tetrapyrroles, which arrested the recovery from nitrogen deficiency. Our data reveal a direct crosstalk between tetrapyrrole biosynthesis and arginine metabolism that highlights the importance of balancing photosynthetic pigment synthesis with nitrogen homeostasis.

• Klíčová slova
• CP: Plants, Synechocystis, arginine metabolism, bilins, chlorophyll, genome-uncoupled-4, nitrogen homeostasis, tetrapyrrole biosynthesis,
• MeSH
• arginin metabolismus   MeSH
• chlorofyl metabolismus   MeSH
• dusík MeSH
• ornithin MeSH
• Synechocystis * metabolismus   MeSH
• Publikační typ
• časopisecké články MeSH
• práce podpořená grantem MeSH
• Názvy látek
• arginin MeSH
• chlorofyl MeSH
• dusík MeSH
• ornithin MeSH

Eurasian spruce bark beetle, Ips typographus, is an aggressive pest among spruce vegetation. I. typographus host trees colonization is mediated by aggregation pheromone, consisting of 2-methyl-3-buten-2-ol and cis-verbenol produced in the beetle gut. Other biologically active compounds such as ipsdienol and verbenone have also been detected. 2-Methyl-3-buten-2-ol and ipsdienol are produced de-novo in the mevalonate pathway and cis-verbenol is oxidized from α-pinene sequestrated from the host. The pheromone production is presumably connected with further changes in the primary and secondary metabolisms in the beetle. To evaluate such possibilities, we obtained qualitative metabolomic data from the analysis of beetle guts in different life stages. We used Ultra-high-performance liquid chromatography-electrospray ionization-high resolution tandem mass spectrometry (UHPLC-ESI-HRMS/MS). The data were dereplicated using metabolomic software (XCMS, Camera, and Bio-Conductor) and approximately 3000 features were extracted. The metabolite was identified using GNPS databases and de-novo annotation in Sirius program followed by manual curation. Further, we obtained differential gene expression (DGE) of RNA sequencing data for mevalonate pathway genes and CytochromeP450 (CyP450) genes from the gut tissue of the beetle to delineate their role on life stage-specific pheromone biosynthesis. CyP450 gene families were classified according to subclasses and given individual expression patterns as heat maps. Three mevalonate pathway genes and five CyP450 gene relative expressions were analyzed using quantitative real-time (qRT) PCR, from the gut tissue of different life stage male/female beetles, as extended knowledge of related research article (Ramakrishnan et al., 2022). This data provides essential information on pheromone biosynthesis at the molecular level and supports further research on pheromone biosynthesis and detoxification in conifer bark beetles.

• Klíčová slova
• Bark beetle, De-novo, Gut tissue, Omics, Pheromone biosynthesis, Spruce,
• Publikační typ
• časopisecké články MeSH

Seedling de-etiolation is one of the key stages of the plant life cycle, characterized by a strong rearrangement of the plant development and metabolism. The conversion of dark accumulated protochlorophyllide to chlorophyll in etioplasts of de-etiolating plants is taking place in order of ns to µs after seedlings illumination, leading to detectable increase of chlorophyll levels in order of minutes after de-etiolation initiation. The highly complex chlorophyll biosynthesis integrates number of regulatory events including light and hormonal signaling, thus making de-etiolation an ideal model to study the underlying molecular mechanisms. Here we introduce the iReenCAM, a novel tool designed for non-invasive fluorescence-based quantitation of early stages of chlorophyll biosynthesis during de-etiolation with high spatial and temporal resolution. iReenCAM comprises customized HW configuration and optimized SW packages, allowing synchronized automated measurement and analysis of the acquired fluorescence image data. Using the system and carefully optimized protocol, we show tight correlation between the iReenCAM monitored fluorescence and HPLC measured chlorophyll accumulation during first 4h of seedling de-etiolation in wild type Arabidopsis and mutants with disturbed chlorophyll biosynthesis. Using the approach, we demonstrate negative effect of exogenously applied cytokinins and ethylene on chlorophyll biosynthesis during early de-etiolation. Accordingly, we identify type-B response regulators, the cytokinin-responsive transcriptional activators ARR1 and ARR12 as negative regulators of early chlorophyll biosynthesis, while contrasting response was observed in case of EIN2 and EIN3, the components of canonical ethylene signaling cascade. Knowing that, we propose the use of iReenCAM as a new phenotyping tool, suitable for quantitative and robust characterization of the highly dynamic response of seedling de-etiolation.

• Klíčová slova
• Arabidopsis, chlorophyll biosynthesis, cytokinins, de-etiolation, ethylene, fluorescence, iReenCAM,
• Publikační typ
• časopisecké články MeSH

The lipid-derived phytohormone jasmonate (JA) regulates plant growth, development, secondary metabolism, defense against insect attack and pathogen infection, and tolerance to abiotic stresses such as wounding, UV light, salt, and drought. JA was first identified in 1962, and since the 1980s many studies have analyzed the physiological functions, biosynthesis, distribution, metabolism, perception, signaling, and crosstalk of JA, greatly expanding our knowledge of the hormone's action. In response to fluctuating environmental cues and transient endogenous signals, the occurrence of multilayered organization of biosynthesis and inactivation of JA, and activation and repression of the COI1-JAZ-based perception and signaling contributes to the fine-tuning of JA responses. This review describes the JA biosynthetic enzymes in terms of gene families, enzymatic activity, location and regulation, substrate specificity and products, the metabolic pathways in converting JA to activate or inactivate compounds, JA signaling in perception, and the co-existence of signaling activators and repressors.

• Klíčová slova
• Activators, SCFCOI1–JAZ co-receptor complex, amino acid conjugates, biosynthesis, jasmonic acid, metabolism, perception, repressors, signaling.,
• MeSH
• cyklopentany metabolismus   MeSH
• genetická transkripce MeSH
• oxylipiny metabolismus   MeSH
• regulátory růstu rostlin biosyntéza   MeSH
• rostlinné proteiny genetika   metabolismus   MeSH
• rostliny genetika   metabolismus   MeSH
• signální transdukce MeSH
• Publikační typ
• časopisecké články MeSH
• práce podpořená grantem MeSH
• přehledy MeSH
• Názvy látek
• cyklopentany MeSH
• jasmonic acid MeSH Prohlížeč
• oxylipiny MeSH
• regulátory růstu rostlin MeSH
• rostlinné proteiny MeSH

Epigenetic DNA modifications are pivotal in eukaryotic gene expression, but their regulatory significance in bacteria is less understood. In Synechocystis 6803, the DNA methyltransferase M.Ssp6803II modifies the first cytosine in the GGCC motif, forming N4-methylcytosine (GGm4CC). Deletion of the sll0729 gene encoding M.Ssp6803II (∆sll0729) caused a bluish phenotype due to reduced chlorophyll levels, which was reversed by suppressor mutations. Re-sequencing of 7 suppressor clones revealed a common GGCC to GGTC mutation in the slr1790 promoter's discriminator sequence, encoding protoporphyrinogen IX oxidase, HemJ, crucial for tetrapyrrole biosynthesis. Transcriptomic and qPCR analyses indicated aberrant slr1790 expression in ∆sll0729 mutants. This aberration led to the accumulation of coproporphyrin III and protoporphyrin IX, indicative of impaired HemJ activity. To confirm the importance of DNA methylation in hemJ expression, hemJ promoter variants with varying discriminator sequences were introduced into the wild type, followed by sll0729 deletion. The sll0729 deletion segregated in strains with the GGTC discriminator motif, resulting in wild-type-like pigmentation, whereas freshly prepared ∆sll0729 mutants with the native hemJ promoter exhibited the bluish phenotype. These findings demonstrate that hemJ is tightly regulated in Synechocystis and that N4-methylcytosine is essential for proper hemJ expression. Thus, cytosine N4-methylation is a relevant epigenetic marker in Synechocystis and likely other cyanobacteria.

• Klíčová slova
• DNA methyltransferase, HemJ, cyanobacteria, epigenetic modifications, tetrapyrrole biosynthesis,
• MeSH
• bakteriální proteiny metabolismus   genetika   MeSH
• epigeneze genetická * MeSH
• metylace DNA * MeSH
• mutace MeSH
• promotorové oblasti (genetika) * MeSH
• regulace genové exprese u bakterií MeSH
• Synechocystis * genetika   metabolismus   MeSH
• tetrapyrroly * metabolismus   biosyntéza   MeSH
• Publikační typ
• časopisecké články MeSH
• Názvy látek
• bakteriální proteiny MeSH
• tetrapyrroly * MeSH

Employing aerobic fermentation, Gram-negative bacteria belonging to the genus Xanthomonas produce the high molecular weight natural heteropolysaccharide known as xanthan. It has various amounts of O-acetyl and pyruvyl residues together with D-glucosyl, D-mannosyl, and D-glucuronyl acid residues in a molar ratio of 2:2:1. The unique structure of xanthan allowed its various applications in a wide range of industries such as the food industry, pharmacology, cosmetics and enhanced oil recovery primarily in petroleum. The cultivation medium used in the manufacture of this biopolymer is critical. Many attempts have been undertaken to generate xanthan gum from agro-based and food industry wastes since producing xanthan gum from synthetic media is expensive. Optimal composition and processing parameters must also be considered to achieve an economically viable manufacturing process. There have been several attempts to adjust the nutrient content and feeding method, temperature, pH, agitation and the use of antifoam in xanthan fermentations. Various modifications in technological approaches have been applied to enhance its physicochemical properties which showed significant improvement in the area studied. This review describes the biosynthesis production of xanthan with an emphasis on the importance of the upstream processes involving medium, processing parameters, and other factors that significantly contributed to the final application of this precious polysaccharide.

• Klíčová slova
• Biosynthesis, Production, Xanthan, Xanthan applications, Xanthomonas sp,
• MeSH
• bakteriální polysacharidy MeSH
• fermentace MeSH
• Xanthomonas campestris * metabolismus   MeSH
• Xanthomonas * MeSH
• Publikační typ
• časopisecké články MeSH
• přehledy MeSH
• Názvy látek
• bakteriální polysacharidy MeSH
• xanthan gum MeSH Prohlížeč

Biogenesis of the photosynthetic apparatus requires complicated molecular machinery, individual components of which are either poorly characterized or unknown. The BtpA protein has been described as a factor required for the stability of photosystem I (PSI) in cyanobacteria; however, how the BtpA stabilized PSI remains unexplained. To clarify the role of BtpA, we constructed and characterized the btpA-null mutant (ΔbtpA) in the cyanobacterium Synechocystis sp. PCC 6803. The mutant contained only c. 1% of chlorophyll and nearly no thylakoid membranes. However, this strain, growing only in the presence of glucose, was genetically unstable and readily generated suppressor mutations that restore the photoautotrophy. Two suppressor mutations were mapped into the hemA gene encoding glutamyl-tRNA reductase (GluTR) - the first enzyme of tetrapyrrole biosynthesis. Indeed, the GluTR was not detectable in the ΔbtpA mutant and the suppressor mutations restored biosynthesis of tetrapyrroles and photoautotrophy by increased GluTR expression or by improved GluTR stability/processivity. We further demonstrated that GluTR associates with a large BtpA oligomer and that BtpA is required for the stability of GluTR. Our results show that the BtpA protein is involved in the biogenesis of photosystems at the level of regulation of tetrapyrrole biosynthesis.

• Klíčová slova
• BtpA, Synechocystis sp. PCC 6803, cyanobacteria, glutamyl-tRNA reductase, tetrapyrrole biosynthesis,
• MeSH
• chlorofyl metabolismus   MeSH
• fotosystém I - proteinový komplex genetika   metabolismus   MeSH
• sinice * metabolismus   MeSH
• tetrapyrroly metabolismus   MeSH
• tylakoidy * metabolismus   MeSH
• Publikační typ
• časopisecké články MeSH
• Názvy látek
• chlorofyl MeSH
• fotosystém I - proteinový komplex MeSH
• tetrapyrroly MeSH

• MeSH
• játra metabolismus   MeSH
• nefrektomie * MeSH
• proteosyntéza * MeSH
• psi MeSH
• žlučové pigmenty biosyntéza   MeSH
• zvířata MeSH
• Check Tag
• psi MeSH
• zvířata MeSH
• Publikační typ
• časopisecké články MeSH
• Názvy látek
• žlučové pigmenty MeSH