Human genes typically contain multiple intron s, and in many cases the exons can be joined more than one way to generate multi ple mRNAs, encoding distinct protein isoforms. This process is called alternativ e splicing. The article summarized the human cytochrome P450 pre mRNA alternati v e splicing and their regulatory mechanism and impacts on biological functions.

Cytochrome P450 (CYP) is a complex gene superfamily of proteins that metabolizes a myriad of endogenous and exogenous substrates. Liver-enriched transcription factors (LETF) play a role in the constitutive and tissue-specific expression of hepatic genes. In this review, six families of LETF that play a role in the tissue-specific, developmental, sexual and temporal regulation of CYP are discussed.

NAD +-dependent cytosolic glycerol-3-phosphate dehydrogenase in Sacch aromyces cerevisiae is one of the key enzymes in metabolic pathway of glycerol . catalysing the reduction of dihydroxyacetone phosphate to glycerol-3-phosph ate.It has two isoenzymes.To study the differences between their structures, their expression of encoding genes and their functions may help increase the understan ding of the cell response mechanism to the hyperosmotic and anoxic conditions. In this paper the research on the two isoenzymes was reviewed.

Using chemically defined medium as the control, mechanism of corn steep liquor (CSL) in complex medium during glycerol production by Candida glycerinogenes was studied.The results showed that there were three key factors in CSL that had some great influences on glycerol fermentation of C.glycerinogenes, including phosphorus, nitrogen, and trace elements.The maximum glycerol yield of 53.44% was achieved at an optimal phosphorus concentration of 121.75mg/L, where the CSL concentration was 14g/L.Phosphorus in CSL could control the distribution of carbon metabolism flux between EMP pathway and HMP pathway.With the increase in CSL concentrations, superfluous phosphorus could restrain HMP pathway and activate EMP pathway, thus resulting in remarkable changes in various fermentation parameters of complex medium.Nitrogen in CSL could play a cooperative role in the regulative function of phosphorus.However, it was not a suitable nitrogen source for C.glycerinogenes.Trace elements in CSL could markedly improve the glucose consumption rate, accelerate the cell growth, and enhance the glycerol yield.

Wuxistatin, a novel and potent statin, is converted from lovastatin by Amycolatopsis sp. CGMCC1149. In the bioconversion, lovastatin is firstly hydroxylated by a hydroxylase. To obtain the critical hydroxylase, a novel hydroxylase gene was isolated from Amycolatopsis sp. CGMCC1149 by Degenerate PCR and Self-Formed Adaptor PCR and expressed in Escherichia coli. BLAST sequence analysis revealed that the gene belonged to cytochrome P450 gene superfamily and could encode a 403-amino-acid protein with a molecular weight of 44.8 kDa. The secondary structure prediction result showed that this protein contained many typical functional regions of P450, such as oxygen binding site, ion-pair region and heme binding region. Meanwhile, a catalytic function verification system was constructed by NADH, ferredoxin and ferredoxin reductase which could catalyze lovastatin hydroxylation into the target product. These would be helpful for further studies in large-scale production of wuxistatin.
Actinomycetales ; enzymology ; genetics ; Amino Acid Sequence ; Butyrates ; metabolism ; Cloning, Molecular ; Cytochrome P-450 Enzyme System ; genetics ; metabolism ; Hydroxylation ; Industrial Microbiology ; Lovastatin ; metabolism ; Molecular Sequence Data

In the reductive branch, glycerol is first dehydrated to 3-hydroxypropionaldehyde that is then reduced to 1,3-PD under the consumption of reducing power (NADH). If over-expression of the gene dhaB encoding glycerol dehydrase is achieved,the reducing power will be scarce and 3-hydroxypropionaldehyde will be accumulated,which is disadvantage to produce 1,3-propanediol.The structure gene yqhD from E.coli encoding 1,3-propanediol oxidoreductase isoenzyme[under the consumption of reducing power (NADPH)]and the gene dhaB encoding glycerol dehydrase from Klebsiella pneumoniae was amplified using PCR method.The two gene were transferred into expression vector pEtac to construct a novel recombinant Klebsiella pneumoniae (pEtac-dhaB-tac-yqhD).Over-expression of yqhD and dhaB in Klebsiella pneumoniae was achieved with pEtac-dhaB-tac-yqhD.The fermentation result on aerobic conversion showed the increase of 20% of 1,3-propanediol yield by Klebsiella pneumoniae(pEtac-dhaB-tac-yqhD) was obtained compared with Klebsiella pneumoniae.The main by-products,acetic acid and butanediol decreased estrogen receptors 30% obviously.

Objective To investigate the effect of PKG on the secretion of IL-6, IL-10, and TNF-αin THP-1 macrophage-derived foam cells. Methods THP-1 monocytes were induced to construct macrophages by treating with 160 nmol/L TPA. Then the macrophages were further treated with 50 mg/L ox-LDL to become foam cells. Four groups were set in this study, including the macrophage group, the foam cell group, the group of foam cell treated with PKG agonist 8-Br-cGMP, and the group of foam cell treated with PKG inhibitor KT-5823. The morphology of THP-1 cells, macrophages and foam cells were observed under microscope. The cellular lipid accumulation was detected by oil red ostaining. The secretion of IL-6, IL-10, and TNF-α into the supernatant was detected by ELISA assay. Results The foam cell was obtained after macrophage incubated with ox-LDL for 48 hours. The secretion of IL-6 and TNF-α increased significantly from the foam cells than that from the macrophages (P<0.05). After the THP-1 monocyte-derived macrophages were incubated with 8-Br-cGMP, the secretion of IL-6 in the supernatant decreased significantly ( P < 0 . 05 ) and IL-10 level in the supernatant increased significantly (P < 0.05). After the macrophages were incubated with KT-5823, the secretion of IL-10 decreased significantly (P<0.05), but the secretion of IL-6 was not significantly changed (P>0.05). After incubation with 8-Br-cGMP, the secretion of IL-6 and TNF-α from the macrophage-derived foam cells decreased significantly (P < 0.05), but IL-10 increased significantly (P<0.05). After the foam cells were treated with KT-5823, the secretion of IL-6 and TNF-αwere also decreased significantly (P<0.05), with no significant change of IL-10 secretion (P > 0.05). Conclusions PKG may enhance the expression of anti-inflammatory cytokine IL-10, and inhibit the expression of inflammatory cytokine IL-6 and TNF-α, contributing to prevent the development of inflammation. PKG might have a potential anti-atherosclerosis effect.

The structural gene encoding mature peptide of extracellular ? amylase was amplified from the genome DNA of hyperthermophilic archaeon Pyrococcus furiosus by PCR The recombinant plasmid pUC19 amy was constructed by inserting the amplified segment into vector pUC19 The recombinant vector pYX212 amy was constructed by ligate the heterogeneous fragment of pUC19 amy into the multiple cloning site of pYX212, an expression vector of yeast Saccharomyces cerevisiae W303 A1 were transformed with pYX212 amy by electroporation The transformant expressed the activity of the thermophilic ? amylase successfully The recombinant enzyme has the similar enzymatic properties as the extracellular ? amylase produced by Pyrococcus furiosus : it shows an enzymatic activity optimum at pH 5 0, and its optimal temperature for enzymatic activity is about 90℃, more than 50% of its initial enzymatic activity is still detectable after it was incubated at 121℃ for 30 minutes

The knock out vector pHK was constructed with E coli vector pET 28a and shuttle vector pHY300PL, by using denatured DNA and homologous recombination technique, the kanamycin resistance gene ( Kan r) from integrated alkaline protease gene engineering strain BP071 was knocked out successfully, and the 11 positive clones were obtained The yield of the best positive clone BP0715 was stable as same as BP071 The methods provided the good experience for the industrial microbiology research, and it was foundation for studying on the safety of genetically modified organisms

The article introduce a rapid method for preparation of fungal chromosome DNA In this method the quartz sand is used to break the fungal cell wall and the chromosome DNA is harvested rapidly in 1～2 h The method is applied successfully by the author to four kinds of fungi Neurospora crassa , Aspergillus oryzae , Morchella esculcnta , Saccharomyces cervisae All the chromosome DNA extracted has the fragment size lager than 20 kb and can be used directly for either digestion with restriction endoenzyme or PCR