The RNA landscape of Dunaliella salina in response to short-term salt stress.

Using the halotolerant green microalgae Dunaliella salina as a model organism has special merits, such as a wide range of salt tolerance, unicellular organism, and simple life cycle and growth conditions. These unique characteristics make it suitable for salt stress study. In order to provide an overview of the response of Dunaliella salina to salt stress and hopefully to reveal evolutionarily conserved mechanisms of photosynthetic organisms in response to salt stress, the transcriptomes and the genome of the algae were sequenced by the second and the third-generation sequencing technologies, then the transcriptomes under salt stress were compared to the transcriptomes under non-salt stress with the newly sequenced genome as the reference genome. The major cellular biological processes that being regulated in response to salt stress, include transcription, protein synthesis, protein degradation, protein folding, protein modification, protein transport, cellular component organization, cell redox homeostasis, DNA repair, glycerol synthesis, energy metabolism, lipid metabolism, and ion homeostasis. This study gives a comprehensive overview of how Dunaliella salina responses to salt stress at transcriptomic level, especially characterized by the nearly ubiquitous up-regulation of the genes involving in protein folding, DNA repair, and cell redox homeostasis, which may confer the algae important mechanisms to survive under salt stress. The three fundamental biological processes, which face huge challenges under salt stress, are ignored by most scientists and are worth further deep study to provide useful information for breeding economic important plants competent in tolerating salt stress, other than only depending on the commonly acknowledged osmotic balance and ion homeostasis.

[Preparation and application of rabbit polyclonal antibody against human lactate dehydrogenase C4(LDHC4)].

Objective To prepare rabbit polyclonal antibody specifically against human lactate dehydrogenase C4 (LDHC4). Methods Site-directed mutation was performed by PCR to generate the mutated LDHC gene, and the mutated gene was ligated into the pET-28a vector to form the pET-28a-LDHC recombinant expression vector. The recombinant vector was introduced into E. coli BL21 (DE3), and LDHC4 protein was obtained by induced expression. The recombinant protein was used as an antigen to immunize New Zealand rabbits, and the antiserum was obtained after three boosted immunizations. The titer of the antiserum against LDHC4 were detected by ELISA. Western blot was used to detect the specificity of the antiserum, and immunohistochemistry was used to detect the expression of LDHC4 in human triple-negative breast cancer tissue. Results A specific rabbit anti-human LDHC4 polyclonal antibody was obtained with an antibody titer of 1:51 200. The antibody can be used for Western blot and immunohistochemistry. Conclusion The specific rabbit anti-human LDHC4 polyclonal antibody is successfully prepared.

In-silico analysis of ligand-receptor binding patterns of α-MMC, TCS and MAP30 protein to LRP1 receptor.

Alpha-momorcharin (α-MMC), trichosanthin (TCS), and momordica anti-HIV protein of 30 kD (MAP30) are potential anti-tumor drug candidates but have cytotoxicity to normal cells. The binding of these proteins to LRP1 receptor and the subsequent endocytosis are essential to their cytotoxicity, but this binding process remains largely unknown. This study, in-silico analysis of the binding patterns, was conducted via the protein-protein docking software, ZDOCK 3.0.2 package, to better understand the binding process. Specifically, α-MMC, TCS and MAP30 were selected and bound to binding subunits CR56 and CR17 of LRP1. After docking, the 10 best docking solutions are retained based on the default ZDOCK scores and used for structural assessment. Our results showed that, α-MMC bound to LRP1 stably at the amino acid residues 1-20, at which 8 residues formed 21 hydrogen bonds with 15 residues of CR56 and 10 residues formed 15 hydrogen bonds with 12 residues of CR17. In contrast, TCS and MAP30 bound mainly to LRP1 at the residues 1-57/79-150 and residues 58-102, respectively, which were functional domains of TCS and MAP30. Since residues 1-20 are outside the functional domain of α-MMC, α-MMC is considered more suitable to attenuate by mutating the receptor binding site. Thus, our analysis lays the foundation for future genetic engineering work on α-MMC, and makes important contributions to its potential clinical use in cancer treatment.