Grb2 and Gab2 form a complex implicated in normal cell signaling and cancer development. Binding of the Grb2SH3C domain to Gab2 is essential for the interaction, but molecular details remained undefined. Using peptide arrays and isothermal titration calorimetry, two Grb2SH3C binding sites in Gab2 (Gab2a and Gab2b) were confirmed and characterized. Gab2a bears similarity to a p27Kip1 epitope that also binds Grb2SH3C. Crystal structures of both Gab2 epitopes complexed with Grb2SH3C reveal that Gab2b contains a 3(10) helix that positions the arginine and lysine of the core-binding motif RxxK in parallel orientation. In contrast, the Gab2a RxxK motif is embedded in a PPII helix with Arg and Lys in staggered orientation. A similar interaction mode is also present in a new complex of Mona/GadsSH3C with an RxxxxK epitope from the putative phosphatase HD-PTP. In summary, our study reveals interaction types of SH3 domains, highlighting their great versatility.

Plant-pathogenic fungi and their hosts engage in chemical warfare, attacking each other with toxic products of secondary metabolism and defending themselves via an arsenal of xenobiotic metabolizing enzymes. One such enzyme is homologous to arylamine N-acetyltransferase (NAT) and has been identified in Fusarium infecting cereal plants as responsible for detoxification of host defence compound 2-benzoxazolinone. Here we investigate functional diversification of NAT enzymes in crop-compromising species of Fusarium and Aspergillus, identifying three groups of homologues: Isoenzymes of the first group are found in all species and catalyse reactions with acetyl-CoA or propionyl-CoA. The second group is restricted to the plant pathogens and is active with malonyl-CoA in Fusarium species infecting cereals. The third group generates minimal activity with acyl-CoA compounds that bind non-selectively to the proteins. We propose that fungal NAT isoenzymes may have evolved to perform diverse functions, potentially relevant to pathogen fitness, acetyl-CoA/propionyl-CoA intracellular balance and secondary metabolism.

Xenobiotic metabolising N-acetyltransferases (NATs) perform biotransformation of drugs and carcinogens. Human NAT1 is associated with endogenous metabolic pathways of cells and is a candidate drug target for cancer. Human NAT2 is a well-characterised polymorphic xenobiotic metabolising enzyme, modulating susceptibility to drug-induced toxicity. Human NATs are difficult to express to high purification yields, complicating large-scale production for high-throughput screens or use in sophisticated enzymology assays and crystallography. We undertake comparative functional investigation of the NAT homologues of ten non-human primates, to characterise their properties and evaluate their suitability as models of human NATs. Considering the amount of generated recombinant protein, the enzymatic activity and thermal stability, the NAT homologues of non-human primates are demonstrated to be a much more effective resource for in vitro studies compared with human NATs. Certain NAT homologues are proposed as better models, such as the NAT1 of macaques Macaca mulatta and M. sylvanus, the NAT2 of Erythrocebus patas, and both NAT proteins of the gibbon Nomascus gabriellae which show highest homology to human NATs. This comparative investigation will facilitate in vitro screens towards discovery and optimisation of candidate pharmaceutical compounds for human NAT isoenzymes, while enabling better understanding of NAT function and evolution in primates.

AT-rich interaction domain 1A gene (ARID1A) encodes for a subunit of the switch/sucrose non-fermentable (SWI/SNF) complex, a chromatin remodeling complex, and it has been implicated in the pathogenesis of various cancer types. In this review, we discuss how ARID1A is linked to endometrial cancer and what molecular pathways are affected by mutation or inhibition of ARID1A. We also discuss the potential use of ARID1A not only as a prognostic biomarker, but also as a target for therapeutic interventions. The dynamic modification of chromatin structure in a temporal-and spatial-specific manner determines cell fate by regulating expression levels of specific genes. The complexity of this process is further highlighted when considering all the endogenous and exogenous signals received by each cell during development and throughout its life. Numerous molecules (proteins and RNA) and macromolecular complexes are responsible for the organization of nucleosomes (Figure 1), epigenetic modifications, the dynamic change between the 'relaxed' or 'tight' conformation of chromatin (euchromatin and heterochromatin, respectively) and the accessibility of gene promoters determining cellular activities such as gene transcription, DNA repair and cell differentiation. Thus, disruption of normal chromatin remodeling impairs cellular development and homeostasis, and it has been associated extensively with tumorigenesis [reviewed in (1)]. The switch/sucrose non-fermentable (SWI/SNF) complex is a nucleosome-remodeling factor found in both eukaryotes and prokaryotes. It is involved in gene expression through transcriptional regulation and plays a pivotal role in carcinogenesis (2). This complex changes the DNA conformation in nucleosomes, allowing recruitment of transcription factors or other complexes responsible for DNA repair, replication and proliferation. Thus, when the SWI/SNF complex is disrupted, aberrant cell cycling is observed, as well as a loss of control of proliferation (3). SWI/SNF is a multi-subunit complex and many of its subunits, such AT-rich interaction domain 1A (ARID1A), ARID1B, SWI/SNF related, matrix associated, actin dependent regulator of chromatin, subfamily A, member 2 (SMARCA2) and SMARCA4 (Figure 2), have been incriminated as driving mutations in various cancer types due to the high mutation frequencies observed (4). In particular, when considering human primary cancer cases with mutations in the SWI/SNF complex, most of the mutations seen are encountered in the gene encoding ARID1A (5-7). ARID1A and ARID1B genes encode DNA-targeting subunits, while SMARCA2 and SMARCA4 encode ATPase enzymes. The mutation frequency of these subunits in different cancer types seems to be tumor type-specific indicating that there is probably differential participation of the complex in gene regulation in different tissues (4). Loss of ARID1A has been shown in numerous human malignancies, such as uterine endometrioid carcinoma (8-10), ovarian endometrioid carcinoma (11), gastric cancer (12, 13), esophageal adenocarcinoma (14), pan...

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Aim: The study aimed to provide an overall view of current data considering the presence of microRNAs in amniotic fluid. Methods: The available literature in MEDLINE, regarding the role of the amniotic fluid in pregnancy and fetal development, was searched for related articles including terms such as “microRNA”, “Amniotic fluid”, “Adverse outcome” and others. Results: The amniotic fluid has an undoubtedly significant part in fetal nutrition, with a protecting and thermoregulatory role alongside. MicroRNAs have proven to be highly expressed during pregnancy in many body liquids including amniotic fluid and are transferred between cells loaded in exosomes, while they are also implicated in many processes during fetal development and could be potential biomarkers for early prediction of adverse outcomes. Conclusion: Current knowledge reveals that amniotic fluid microRNAs participate in many developmental and physiological processes of pregnancy including proliferation of fibroblasts, fetal development, angiogenesis, cardioprotection, activation of signaling pathways, differentiation and cell motility, while the expression profile of specific microRNAs has a potential prognostic role in the prediction of Down syndrome, congenital hydronephrosis and kidney fibrosis.

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Background: Cheese microbiome plays a key role in determining the organoleptic and physico-chemical properties and may be also used as an authenticity tool for distinguishing probiotic cultures. Due to significant reduction of cell viability often witnessed during food production processes and storage, immobilization is proposed to ascertain high probiotic cell loads required to confer the potential health benefits. Hence, the aim of the present study was to investigate the effect of free or immobilized Lactiplantibacillus plantarum T571 on whey protein on feta cheese microbiome. Methods: Next-Generation Sequencing technology was used to investigate cheese microbiome. Cheese samples containing free or immobilized Lactiplantibacillus plantarum T571 (a wild type strain isolated from Feta cheese brine) on whey protein, along with products containing commercial starter culture, were analyzed. Results: The results showed a great diversity of bacteria and fungi genera among the samples. An increased presence of Lactobacillus OTUs in cheese with immobilized cells on whey protein was witnessed, highlighting the survival of the strain in the final product. The immobilized culture had also a significant impact on other genera, such as Lactococcus, Leuconostoc and Debaryomyces, which are associated with improved technological characteristics and health benefits. Conclusions: Enrichment of feta cheese with immobilized potential probiotics to secure cell viability consists of an industrial challenge and leads to distinct microbiome composition that may be used as a valuable food authenticity tool.