the Kunitz/Bpti-type peptides are ubiquitous in numerous organisms including marine venomous animals. the peptides demonstrate various biological activities and therefore they are the subject of a number of investigations. We have discovered a new HciQ subfamily belonging to recently described multigene HcGS family of Heteractis crispa Kunitz-peptides. the uniqueness of this subfamily is that the HciQ precursors contain a propeptide terminating in Lys-Arg (endopeptidase cleavage site) the same as in the neuro-and cytotoxin ones. Moreover, the HCIQ genes contain two introns in contrast to HCGS genes with one intron. As a result of Sanger and amplicon deep sequencings, 24 HCIQ isoforms were revealed. The recombinant peptides for the most prevalent isoform (HCIQ2c1) and for the isoform with the rare substitution Gly17Glu (HCIQ4c7) were obtained. They can inhibit trypsin with K i 5.2 × 10 −8 M and K i 1.9 × 10 −7 M, respectively, and interact with some serine proteinases including inflammatory ones according to the SPR method. For the first time, Kunitz-peptides have shown to significantly increase neuroblastoma cell viability in an in vitro 6-OHDA-induced neurotoxicity model being a consequence of an effective decrease of ROS level in the cells. Kunitz-type proteinase inhibitors are present in various living organisms and in viruses. They are widely distributed and well-characterized in animals including marine invertebrates, snakes, spiders, ticks, flies and mammals 1. In spider, snake, scorpion, cone snail and sea anemone venoms Kunitz-peptides may exist in multiple isoforms possessing conserved BPTI-like fold but exhibit different biological activities 2-9. This phenomenon is associated with gene duplication and their diversification throughout adaptive evolution leading to the formation of families of evolutionarily related but functionally distinct genes 10. Among sea anemone transcriptomes, such multigene families have been discovered in Anemonia viridis 11 , Stichodactyla haddoni 12 , and Heteractis crispa 5. HCGS multigene family of H. crispa has been found to be divided in four distinct subfamilies (GS, RG, GG, and GN) forming the combinatory library of Kunitz/BPTI peptides 5. The group of HCGN peptides was presented by one sequence, different from other sequences that are characterized by a propeptide insertion containing the cleavage site Lys-Arg, and additional residues Ile-Gln at the N-terminus of a mature peptide. Its full-length homolog HMIQ3c1, containing a mature peptide with the same residues at N-terminus, was derived from the cDNA of the sea anemone Heteractis magnifica 13. The most abundant HCGS and HCRG peptides are being actively studied nowadays 14-17. The main targets of Kunitz-peptides are serine proteinases, such as trypsin and α-chymotrypsin.

We obtained two novel draft genomes of type Zobellia strains with estimated genome sizes of 5.14 Mb for Z. amurskyensis KMM 3526Т and 5.16 Mb for Z. laminariae KMM 3676Т. Comparative genomic analysis has been carried out between obtained and known genomes of Zobellia representatives. The pan-genome of Zobellia genus is composed of 4853 orthologous clusters and the core genome was estimated at 2963 clusters. The genus CAZome was represented by 775 GHs classified into 62 families, 297 GTs of 16 families, 100 PLs of 13 families, 112 CEs of 13 families, 186 CBMs of 18 families and 42 AAs of six families. A closer inspection of the carbohydrate-active enzyme (CAZyme) genomic repertoires revealed members of new putative subfamilies of GH16 and GH117, which can be biotechnologically promising for production of oligosaccharides and rare monomers with different bioactivities. We analyzed AA3s, among them putative FAD-dependent glycoside oxidoreductases (FAD-GOs) being of particular interest as promising biocatalysts for glycoside deglycosylation in food and pharmaceutical industries.

The capability of Yersinia ruckeri to survive in the aquatic systems reflects its adaptation (most importantly through the alteration of membrane permeability) to the unfavorable environments. The nonspecific porins are a key factor contributing to the permeability. Here we studied the influence of the stimuli, such as temperature, osmolarity, and oxygen availability on regulation of Y. ruckeri porins. Using qRT‐PCR and SDS‐PAGE methods we found that major porins are tightly controlled by temperature. Hyperosmosis did not repress OmpF production. The limitation of oxygen availability led to decreased expression of both major porins and increased transcription of the minor porin OmpY. Regulation of the porin balance in Y. ruckeri, in spite of some similarities, diverges from that system in Escherichia coli. The changes in porin regulation can be adapted in Y. ruckeri in a species‐specific manner determined by its aquatic habitats.

We carried out a detailed investigation of PL7 alginate lyases across the Zobellia genus. The main findings were obtained using the methods of comparative genomics and spatial structure modeling, as well as a phylogenomic approach. Initially, in order to elucidate the alginolytic potential of Zobellia, we calculated the content of polysaccharide lyase (PL) genes in each genome. The genus-specific PLs were PL1, PL6, PL7 (the most abundant), PL14, PL17, and PL40. We revealed that PL7 belongs to subfamilies 3, 5, and 6. They may be involved in local and horizontal gene transfer and gene duplication processes. Most likely, an individual evolution of PL7 genes promotes the genetic variability of the Alginate Utilization System across Zobellia. Apparently, the PL7 alginate lyases may acquire a sub-functionalization due to diversification between in-paralogs.

Here, we investigated general porin regulation in Yersinia pseudotuberculosis 488, the causative agent of Far Eastern scarlet-like fever, in response to sublethal concentrations of antibiotics. We chose four antibiotics of different classes and measured gene expression using qRT-PCR and GFP reporter systems. Our data showed temporal regulation of the general porin genes ompF and ompC caused by antibiotic stress. The porin transcription initially decreased, providing early defensive response of the bacterium, while it returned to that of the untreated cells on prolonged antibiotic exposure. Unlike the major porin genes, the transcription of the alternative porin genes ompX and lamB was increased. Moreover, a short-term ompR- and marA-mediated porin regulation was observed. The main finding was a phenotypic heterogeneity of Y. pseudotuberculosis population manifested in variable porin gene expression under carbenicillin exposure. This may offer adaptive fitness advantages for a particular bacterial subpopulation.

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Twenty-three bacterial strains were isolated from the secreted mucus trapping net of themarine polychaete Chaetopterus variopedatus (phylum Annelida) and twenty strains were identifiedusing 16S rRNA gene analysis. Strain CB1-14 was recognized as a new species of the genus Vibriousing the eight-gene multilocus sequence analysis (MLSA) and genome sequences of nineteen typeVibrio strains. This Vibrio sp. was cultured, and 6-epi-monanchorin (2), previously isolated from thepolychaete and two sponge species, was found in the cells and culture broth. The presence of the 6-epi-monanchorin was confirmed by its isolation followed by 1H NMR and HRESIMS analysis. Theseresults showed the microbial origin of the bicyclic guanidine alkaloid 2 in C. variopedatus.