• Asian-Australasian Journal of Animal Sciences
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• v.33 no.6
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• pp.1012-1022
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• 2020

Objective: Caseins and fatty acids of milk are synthesized and secreted by the epithelial cells of the mammary gland. All-trans retinoic acid (ATRA), an active metabolite of vitamin A, has been shown to promote mammary development. This study was conducted to determine the effect of ATRA on casein synthesis and fatty acid composition in MAC-T cells. Methods: MAC-T cells were allowed to differentiate for 4 d, treated with ATRA (0, 1.0, 1.5, and 2.0 μM), and incubated for 3 d. We analyzed the fatty acid composition, the mRNA expression of casein and fatty acid synthesis-related genes, and the phosphorylation of casein synthesis-related proteins of MAC-T cells by gas chromatography, quantitative polymerase chain reaction, and western blotting, respectively. Results: In MAC-T cells, ATRA increased the mRNA levels of α_S1-casein and β-casein, janus kinase 2 (JAK2) and E74-like factor 5 of the signal transducer and activator of transcription 5 β (STAT5-β) pathway, ribosomal protein S6 kinase beta-1 (S6K1) and eukaryotic translation initiation factor 4E binding protein 1 of the mammalian target of rapamycin (mTOR) pathway, inhibited the mRNA expression of phosphoinositide 3-kinase and eukaryotic initiation factor 4E of the mTOR pathway, and promoted the phosphorylation of STAT5-β and S6K1 proteins. Additionally, ATRA increased the de novo synthesis of fatty acids, reduced the content of long-chain fatty acids, the ratio of monounsaturated fatty acids to saturated fatty acids (SFA), the ratio of polyunsaturated fatty acids (PUFA) to SFA, and the ratio of ω-6 to ω-3 PUFA. The mRNA levels of acetyl-CoA carboxylase 1, fatty acid synthase, lipoprotein lipase, stearoyl-CoA desaturase, peroxisome proliferator-activated receptor gamma, and sterol regulatory element-binding protein 1 (SREBP1) were enhanced by ATRA. Conclusion: ATRA promotes the synthesis of casein by regulating JAK2/STAT5 pathway and downstream mTOR signaling pathway, and it improves the fatty acid composition of MAC-T cells by regulating SREBP1-related genes.

• Journal of Microbiology and Biotechnology
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• v.25 no.2
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• pp.152-161
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• 2015

CodY is a highly conserved protein in low G+C gram-positive bacteria that regulates genes involved in sporulation and stationary-phase adaptation. Bacillus thuringiensis is a grampositive bacterium that forms spores and parasporal crystals during the stationary phase. To our knowledge, the regulatory mechanism of CodY in B. thuringiensis is unknown. To study the function of CodY protein in B. thuringiensis, BMB171codY^- was constructed in a BMB171 strain. A shuttle vector containing the ORF of cry1Ac10 was transformed into BMB171 and BMB171codY^-, named BMB171cry1Ac and BMB171codY^-cry1Ac, respectively. Some morphological and physiological changes of codY mutant BMB171codY^-cry1Ac were observed. A comparative proteomic analysis was conducted for both BMB171codY^-cry1Ac and BMB171cry1Ac through two-dimensional gel electrophoresis and MALDI-TOF-MS/MS analysis. The results showed that the proteins regulated by CodY are involved in microbial metabolism, including branched-chain amino acid metabolism, carbohydrate metabolism, fatty acid metabolism, and energy metabolism. Furthermore, we found CodY to be involved in sporulation, biosynthesis of poly-β-hydroxybutyrate, growth, genetic competence, and translation. According to the analysis of differentially expressed proteins, and physiological characterization of the codY mutant, we performed bacterial one-hybrid and electrophoretic mobility shift assay experiments and confirmed the direct regulation of genes by CodY, specifically those involved in metabolism of branched-chain amino acids, ribosomal recycling factor FRR, and the late competence protein ComER. Our data establish the foundation for in-depth study of the regulation of CodY in B. thuringiensis, and also offer a potential biocatalyst for functions of CodY in other bacteria.

• Biomedical Science Letters
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• v.6 no.1
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• pp.11-17
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• 2000

SNAP-25 was first investigated as a neuron-specific protein preferentially expressed in CA3 pyramidal neurons of mouse hippocampus. It is a presynaptic plasma membrane protein in the nerve cell and plays an important role in the synaptic vesicle membrane docking and fusion pathway. We have recently isolated SNAP-25 cDNA from a rat brain cDNA library using a probe of Z2 cDNA. It consisted of 2,101 bp and an open reading frame (ORF) was identified between nucleotides (nt) 209 and 827. The AUG codon (nt 209∼211) was surrounded by CTACCATGG, which corresponded to the consensus sequence of ribosomal binding site. The ORF was terminated by TAA (nt 827∼829) to encode a polypeptide of 206 amino acid residues. The 3'-untranslated region contained two extensive stretches of repeated (CA)28 and (CA)19 at positions 925∼980 and 1645∼1682. It is noteworthy that cysteine residues were clustered in the span of amino acid residues 84∼991 : Cys-Gly-Leu-Cys-Val-Cys-Pro-Cys. Rat SNAP-25 showed 88% and 97% identity in nucleotide sequences to that of human and mouse, respectively. Amino acid sequence of rat SNAP-25 showed 100% identity to that of mouse and human SNAP-21.

• Korean Journal of Microbiology
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• v.46 no.2
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• pp.223-227
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• 2010

RNase E plays a major role in the degradation and processing of a large number of RNA transcripts in Escherichia coli and forms the core component of the degradosome, a large protein complex involved in RNA metabolism. RraA and RraB are recently discovered protein inhibitors of RNase E and are evolutionarily conserved. In this study, we observed that, unlike RraA, overexpression of RraB did not rescue growth arrest of E. coli cells overexpressing RNase E. To examine whether this phenomenon stems from differential inhibitory effects of RraA and RraB on RNase E substrates, we analyzed three in vivo RNase E substrates. The results showed that RraA inhibited RNase E activity more efficiently than RraB on the degradation of RNA I, which controls the copy number of ColE1-type plasmid, and rpsO mRNA encoding ribosomal protein S15, while RraB was unable to inhibit the processing of pM1 RNA, a precursor of the RNA component of RNase P, by RNase E. Our results imply that RraB inhibits RNase E activity in a more substrate-dependent manner than RraA and this property of RraB may explain why overexpression of RraB could not rescue cells overexpressing RNase E from growth arrest.

• IMMUNE NETWORK
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• v.1 no.1
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• pp.7-13
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• 2001

Currently 18 monoclonal antibodies were approved by FDA for inj ection into humans for therapeutic or diagnostic purpose. And 146 clinical trials are under way to evaluate the efficacy of monoclonal antibodies as anti-cancer agents, which comprise 9 % of clinical trials in cancer therapy field. When considering a lot of disappointment and worries existed in this field during the past 15 years, this boom could be called as resurrection. Antibodies have several merits over small molecule drug. First of all it is easier and faster in development, as proper immunization of the target proteins usually raises good antibody response. The side effects of antibodies are more likely to be checked out in immunohistomchemical staining of whole human tissues. Antibody has better pharmacokinetics, which means a longer half-life. And it is non-toxic as it is purely a "natural drug. Vast array of methods was developed to get the recombinant antibodies to be used as drug. The mice with human immunoglobulin genes were generated. Fully human antibodies can be developed in fast and easy way from these mice through immunization. These mice could make even human monoclonal antibodies against any human antigen like albumin. The concept of combinatorial library was also actively adopted for this purpose. Specific antibodies can be screened out from phage, mRNA, ribosomal library displaying recombinant antibodies like single chain Fvs or Fabs. Then the coding genes of these specific antibodies are obtained from the selected protein-gene units, and used for industrial scale production. Both $na\ddot{i}ve$ and immunized libraries are proved to be effective for this purpose. In post-map arena, antibodies are receiving another spotlight as molecular probes against numerous targets screened out from functional genomics or proteomics. Actually many of these antibodies used for this purpose are already human ones. Through alliance of these two actively growing research areas, antibody would play a central role in target discovery and drug development.

• Asian-Australasian Journal of Animal Sciences
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• v.26 no.1
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• pp.72-81
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• 2013

Four Luxi beef cattle ($400{\pm}10$ kg) fitted with ruminal, duodenal and ileal cannulas were used in a $4{\times}4$ Latin square to assess the effects of soybean small peptide (SSP) infusion on rumen fermentation, diet digestion and flow of nutrient in the gastrointestinal tract. The ruminal infusion of SSP was 0 (control), 100, 200 and 300 g/d. Ruminal SSP infusion linearly (p<0.01) and quadratically (p<0.01) increased microbial protein synthesis and rumen ammonia-N concentration. Concentrations of total volatile fatty acid were linearly increased (p = 0.029) by infusion SSP. Rumen samples were obtained for analysis of microbial ecology by real-time PCR. Populations of rumen Butyrivibrio fibrisolvens, Streptococcus bovis, Ciliate protozoa, Ruminococcus flavefaciens, and Prevotella ruminicola were expressed as a proportion of total Rumen bacterial 16S ribosomal deoxyribonucleic acid (rDNA). Butyrivibrio fibrisolvens populations which related to total bacterial 16S rDNA were increased (p<0.05), while Streptococcus bovis populations were linearly (p = 0.049) and quadratically (p = 0.020) decreased by infusion of SSP. Apparent rumen digestibility of DM and NDF were (Q, p<0.05; L, p<0.05) increased with infusion SSP. Total tract digestion of DM, OM and NDF were linearly (p<0.01) and quadratically (p<0.01) increased by infusing SSP. The flow of total amino acids (AA), essential amino acids (EAA) and individual amino acids were linearly (p<0.01) and quadratically (p<0.01) increased with infusion SSP. The digestibility of Lysine was quadratically (p = 0.033) increased and apparent degradability of Arginine was linearly (p = 0.032) and quadratically (p = 0.042) increased with infusion SSP. The results indicated that infusion SSP could improve nutrient digestion, ruminal fermentation and AA availability.

• BMB Reports
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• v.40 no.2
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• pp.212-217
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• 2007

The chicken oviduct is a dynamic organ that produces secretory proteins such as ovalbumin during the laying period. In this study, we identified oviduct-specific proteins in hens during the egg-laying period by proteomic analysis. Proteins extracted from the magnum of hens of different ages (5, 35, and 65 weeks) were analyzed by two-dimensional gel electrophoresis to compare the intensity of proteins among samples. Approximately 300 spots were detected on each gel. Based on the comparison of image gels, we found that the intensity of eight spots in 35-week magnums was increased at least by 2-fold compared with the others. Five of the eight spots were identified as calumenin, acidic ribosomal phosphoproteins (ARP), prohibitin, heart fatty acid-binding protein, and anterior gradient-2 (AGR-2). In particular, ARP and AGR-2 were highly expressed in 35- week magnums compared with 5- and 65-week magnums. In addition, the level of these proteins was consistent with their RNA levels. Expression of AGR-2 mRNA was detected in the mature magnum, whereas no signal was observed in premature tissue. Among various tissues, expression of AGR-2 mRNA was highest in the magnum, high in the isthmus, and five fold lower in muscle. It was undetectable in the liver and in other tissues (heart and kidney). However, the mRNA levels of other proteins were ubiquitous among tissues. In transcriptional activity of AGR-2, a 3.0 kb fragment of promoter region containing potential estrogen receptor binding sites had enhanced its activity strongly. In conclusion, these results suggest that AGR-2 has functional regulatory roles in the chicken oviduct during the egglaying period.

• Journal of Dairy Science and Biotechnology
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• v.27 no.2
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• pp.1-6
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• 2009

Probiotic bacteria have been administered to neonates to serve as maturational stimuli for the developing gut and intestinal immune system, establish and develop the intestinal microbiota, and mediate host-microbe interactions; further, these bacteria have shown beneficial effects In the treatment and reduction of the risk of infectious diseases, necrotizing enterocolitis, and atopic disease. An LAB isolation project to identify effective lactic acid bacteria for Korean people is in progress. The average total counts of lactic acid bacteria, lactobacilli, bifidobacteria, and coliforms in the fecal samples from 2 provinces were estimated as 8.31, 5.98, 8.13, and 3.01 CFU/g. Additional samples from other provinces will be analyzed to examine the changes in the lactic bacterial counts according to the area, sex of the neonate, mode of delivery, and type of feeding. A database containing the 16S rDNA sequences and the ribosomal protein profile of all the lactic acid bacteria isolated from fecal samples will be constructed. For the effective use of probiotics, a number of clinical studies are needed to formulate guidelines for strain, subject, purpose, and dose.

• Microbiology and Biotechnology Letters
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• v.34 no.1
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• pp.1-6
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• 2006

Harmful algal blooms (HABs or red tides), caused by uncontrolled proliferation of marine phytoplankton, impose a severe environmental problem and occasionally threaten even public health. We sequenced the genome of an EPS-producing marine bacterium Hahella chejuensis that produces a red pigment with the lytic activity against red-tide dinoflagellates at parts per billion level. H. chejuensis is the first sequenced species among algicidal bacteria as well as in the order Oceanospirillales. Sequence analysis indicated a distant relationship to the Pseudomonas group. Its 7.2-megabase genome encodes basic metabolic functions and a large number of proteins involved in regulation or transport. One of the prominent features of the H. chejuensis genome is a multitude of genes of functional equivalence or of possible foreign origin. A significant proportion (${\sim}23%$) of the genome appears to be of foreign origin, i.e. genomic islands, which encode genes for biosynthesis of exopolysaccharides, toxins, polyketides or non-ribosomal peptides, iron utilization, motility, type III protein secretion and pigment production. Molecular structure of the algicidal pigment was determined to be prodigiosin by LC-ESI-MS/MS and NMR analyses. The genomics-based research on H. chejuensis opens a new possibility for controlling algal blooms by exploiting biotic interactions in the natural environment and provides a model in marine bioprospecting through genome research.

• Journal of Microbiology and Biotechnology
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• v.27 no.3
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• pp.591-597
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• 2017

Maribacter dokdonensis DSW-8 was isolated from the seawater off Dokdo in Korea. To investigate the genomic features of this marine bacterium, we sequenced its genome and analyzed the genomic features. After de novo assembly and gene prediction, 16 contigs totaling 4,434,543 bp (35.95% G+C content) in size were generated and 3,835 protein-coding sequences, 36 transfer RNAs, and 6 ribosomal RNAs were detected. In the genome of DSW-8, genes encoding the proteins associated with gliding motility, molybdenum cofactor biosynthesis, and utilization of several kinds of carbohydrates were identified. To analyze the genomic relationships among Maribacter species, we compared publically available Maribacter genomes, including that of M. dokdonensis DSW-8. A phylogenomic tree based on 1,772 genes conserved among the eight Maribacter strains showed that Maribacter speices isolated from seawater are distinguishable from species originating from algal blooms. Comparison of the gene contents using COG and subsystem databases demonstrated that the relative abundance of genes involved in carbohydrate metabolism are higher in seawater-originating strains than those of algal blooms. These results indicate that the genomic information of Maribacter species reflects the characteristics of their habitats and provides useful information for carbon utilization of marine flavobacteria.