Biosynthesis of Biotin-vitamers from Pelargonie Acid by Pseudomonas sp. Strain 393

The biosynthesis of biotin-vitamers from pelargonic acid by Pseudomonas sp. strain 393 was investigated. The main product of biotin-vitamers from pelargonic acid was desthiobiotin. The addition of streptomycin or l-alanine enhanced accumulation of desthiobiotin in culture fluid. Propionic, pimelic and azelaic acids were identified as main metabolites from pelargonic acid. When propionic acid was incubated with resting cells, pelargonic and azelaic acids were formed. The biosynthetic pathway of pelargonic acid to pimelic acid was also studied.     

Tamoxifen-resistant, ER-positive MAC 51 cell line with a high metastatic potential developed from a spontaneous breast cancer mouse model

We developed and characterized an estrogen-responsive and ER-positive murine breast cancer cell line (MAC51) from a spontaneous breast cancer animal model. These cells are overexpressed with K8, K18 and K19 proteins in an immunofluoresence assay. Upregulation of ER alpha was observed in the immunofluoresence assay, real-time PCR analysis and western blot assay. A colocalization experiment in MAC 51 showed cytoplasmic colocalization of K18 and K19 proteins with ER ??. Real-time analysis of tumor samples from engrafted animals, MAC 51, metastatic liver and metastatic ovary revealed overexpression of K8 and K18 compared to the respective controls. A hormone responsive experiment in immunodeficient mice showed highly significant decreases in estrogen and tumor volume after 14 days ovariectomization. The tumorogenicity assay showed higher (3?×?10 ⁵) and lower (3?×?10⁴) concentrations of MAC 51 cells that developed tumors within 2?weeks post-transplantation. Tumor morphology and histology resembled a sarcoma pattern but our spontaneous model appeared in an adenocarcinoma pattern. Metastasis to different organs occurred through hematogenous and lymphatic routes. We assessed the potency of the anticancer effect in MAC 51 cells by treating various anticancer drugs with E2, followed by studying apoptotic gene expression profiles. E2 and E2+ tamoxifen-treated cells showed upregulation of apoptotic genes caspase 1, 3, 9, P53 and Bcl-xl but the tamoxifen- and paclitaxel-treated cells did not upregulate the apoptotic genes. Tamoxifen-resistant, ER-positive and high metastatic potential cell lines from murine origin are very rare. Also, estrogen greatly induced apoptosis in this cell line, hence MAC 51 has a greater application potential to evaluate low doses of estrogen with other targeted therapeutic drugs to treat breast cancer.     

Discovery of alcohol dehydrogenase from mushrooms and application to alcoholic beverages

Saccharomyces cerevisiae is the main microorganism used in alcoholic beverage brewing, because this microbe has alcohol dehydrogenase (ADH) activity. We have recently discovered that some genera of mushrooms produce alcohol dehydrogenase, and made wine, beer and sake using mushrooms in place of S. cerevisiae. The highest alcohol concentrations in the wine, beer and sake were achieved with Pleurotus ostreatus (2648 mM, 12.2%), Tricholoma matsutake (1069 mM, 4.6%) and Agaricus blazei (1736 mM, 8.0%). In the case of wine made using A. blazei, the same alcohol concentration (1736 mM, 8.0%) was produced under both aerobic and anaerobic conditions. This wine produced by A. blazei contained about 0.68% β- -glucan, which is known to have preventive effects against cancer. The wine made using Flammulina velutipes showed thrombosis-preventing activity, giving a prolonged thrombin clotting time 2.2-fold that of the control. Thus, alcoholic beverages made using mushrooms seem to be a functional food source which can be expected to have preventive effects against cancer and thrombosis.     

Dynamic functional relay between insulin receptor substrate 1 and 2 in hepatic insulin signaling during fasting and feeding

Insulin receptor substrate (Irs) mediates metabolic actions of insulin. Here, we show that hepatic Irs1 and Irs2 function in a distinct manner in the regulation of glucose homeostasis. The PI3K activity associated with Irs2 began to increase during fasting, reached its peak immediately after refeeding, and decreased rapidly thereafter. By contrast, the PI3K activity associated with Irs1 began to increase a few hours after refeeding and reached its peak thereafter. The data indicate that Irs2 mainly functions during fasting and immediately after refeeding, and Irs1 functions primarily after refeeding. In fact, liver-specific Irs1-knockout mice failed to exhibit insulin resistance during fasting, but showed insulin resistance after refeeding; conversely, liver-specific Irs2-knockout mice displayed insulin resistance during fasting but not after refeeding. We propose the concept of the existence of a dynamic relay between Irs1 and Irs2 in hepatic insulin signaling during fasting and feeding.     

The antiretroviral potency of APOBEC1 deaminase from small animal species

Although the role of the APOBEC3-dependent retroelement restriction system as an intrinsic immune defense against human immunodeficiency virus type1 (HIV-1) infection is becoming clear, only the rat ortholog of mammalian APOBEC1s (A1) thus far has been shown to possess antiviral activity. Here, we cloned A1 cDNAs from small animal species, and showed that similar to rat A1, both wild-type and Δvif HIV-1 infection was inhibited by mouse and hamster A1 (4- to 10-fold), whereas human A1 had negligible effects. Moreover, rabbit A1 significantly reduced the infectivity of both HIV-1 virions (>300-fold), as well as that of SIVmac, SIVagm, FIV and murine leukemia virus. Immunoblot analysis showed that A1s were efficiently incorporated into the HIV-1 virion, and their packaging is mediated through an interaction with the nucleocapsid Gag domain. Interestingly, there was a clear accumulation of particular C-T changes in the genomic RNAs of HIV-1 produced in their presence, with few G-A changes in the proviral DNA. Together, these data reveal that A1 may function as a defense mechanism, regulating retroelements in a wide range of mammalian species.     

Kid-mediated chromosome compaction ensures proper nuclear envelope formation

Toward the end of mitosis, neighboring chromosomes gather closely to form a compact cluster. This is important for reassembling the nuclear envelope around the entire chromosome mass but not individual chromosomes. By analyzing mice and cultured cells lacking the expression of chromokinesin Kid/kinesin-10, we show that Kid localizes to the boundaries of anaphase and telophase chromosomes and contributes to the shortening of the anaphase chromosome mass along the spindle axis. Loss of Kid-mediated anaphase chromosome compaction often causes the formation of multinucleated cells, specifically at oocyte meiosis II and the first couple of mitoses leading to embryonic death. In contrast, neither male meiosis nor somatic mitosis after the morula-stage is affected by Kid deficiency. These data suggest that Kid-mediated anaphase/telophase chromosome compaction prevents formation of multinucleated cells. This protection is especially important during the very early stages of development, when the embryonic cells are rich in ooplasm.     

Antisense expression of a rice sucrose transporter OsSUT1 in rice (Oryza sativa L.).

We analyzed the function of a rice sucrose transporter, OsSUT1, by using antisense rice. There was no difference between antisense and wild-type plants in carbohydrate content and photosynthetic ability of the flag leaves in the vegetative growth stage, suggesting that OsSUT1 may not play an important role in carbon metabolism, at least in these materials.