ζ-Carotene<Emphasis Type="Italic"> cis</Emphasis> isomers as products and substrates in the plant poly-<Emphasis Type="Italic">cis</Emphasis> carotenoid biosynthetic pathway to lycopene

The plant carotenoid biosynthetic pathway to cyclic carotenes proceeds via carotene precursors in cis configuration. Involvement of individual isomers was elucidated by genetic complementation of desaturations and in vitro reactions of the corresponding enzyme. Determination of substrate and product specificity of phytoene and uc89dyxr53hpa/xxlarge950.gif" alt="zeta" align="MIDDLE" BORDER="0">-carotene desaturase revealed that 15-cis-phytoene is converted to 9,15,9uc89dyxr53hpa/xxlarge8242.gif" alt="prime" align="BASELINE" BORDER="0">-tricis-uc89dyxr53hpa/xxlarge950.gif" alt="zeta" align="MIDDLE" BORDER="0">-carotene with 15,9uc89dyxr53hpa/xxlarge8242.gif" alt="prime" align="BASELINE" BORDER="0">-dicis-phytofluene as intermediate by the first desaturase. Prior to a subsequent conversion by uc89dyxr53hpa/xxlarge950.gif" alt="zeta" align="MIDDLE" BORDER="0">-carotene desaturase, the 15-cis double bond of 9,15,9uc89dyxr53hpa/xxlarge8242.gif" alt="prime" align="BASELINE" BORDER="0">-tricis-uc89dyxr53hpa/xxlarge950.gif" alt="zeta" align="MIDDLE" BORDER="0">-carotene has to be (photo)isomerized to all-trans. Then, the resulting 9,9uc89dyxr53hpa/xxlarge8242.gif" alt="prime" align="BASELINE" BORDER="0">-dicis-uc89dyxr53hpa/xxlarge950.gif" alt="zeta" align="MIDDLE" BORDER="0">-carotene is utilized by uc89dyxr53hpa/xxlarge950.gif" alt="zeta" align="MIDDLE" BORDER="0">-carotene desaturase via 7,9,9uc89dyxr53hpa/xxlarge8242.gif" alt="prime" align="BASELINE" BORDER="0">-tricis-neurosporene to 7,9,7uc89dyxr53hpa/xxlarge8242.gif" alt="prime" align="BASELINE" BORDER="0">,9uc89dyxr53hpa/xxlarge8242.gif" alt="prime" align="BASELINE" BORDER="0">-tetracis-lycopene. Other uc89dyxr53hpa/xxlarge950.gif" alt="zeta" align="MIDDLE" BORDER="0">-carotene isomers that are assumed to be spontaneous isomerization products were not converted, except for the asymmetric 9-cis-uc89dyxr53hpa/xxlarge950.gif" alt="zeta" align="MIDDLE" BORDER="0">-carotene. This isomer is desaturated only to 7,9-dicis-neurosporene resembling a dead-end of the pathway. Prolycopene, the product of the desaturation reactions, is finally isomerized by a specific isomerase to all-trans-lycopene, which is a prerequisite for cyclization to uc89dyxr53hpa/xxlarge946.gif" alt="beta" align="MIDDLE" BORDER="0">-carotene. The 5-cis-lycopene and the 9-cis-and 13-cis-uc89dyxr53hpa/xxlarge946.gif" alt="beta" align="MIDDLE" BORDER="0">-carotene isomers detected in leaves are thought to originate independently from cis precursors by non-enzymatic isomerization of their all-trans forms.     

Long noncoding RNA uc.4 inhibits cell differentiation in heart development by altering DNA methylation

In previous studies, we have demonstrated that long noncoding RNA uc.4 may influence the cell differentiation through the TGF-β signaling pathway, suppressed the heart development of zebrafish and resulting cardiac malformation. DNA methylation plays a significant role in the heart development and disordered of DNA methylation may cause disruption of control of gene promoter. In this study, methylated DNA immunoprecipitation was performed to identify the different expression levels of methylation regions. Gene Ontology and Kyoto Encyclopedia of Genes and Genomes (KEGG) analysis were also performed to identify the possible biological process and pathway that uc.4 may join, associated with Rap1 signaling pathway, gonadotropin-releasing hormone signaling pathway, and Calcium signaling pathway. We found that the distribution of differentially methylated regions peaks was mainly located in intergenic and intron regions. Altogether, our result showed that differentially methylated genes are significantly expressed in uc.4-overexpression cells, providing valuable data for further exploration of the role of uc.4 in heart development.     

The long noncoding RNA uc.294 is upregulated in early-onset pre-eclampsia and inhibits proliferation,invasion of trophoblast cells (HTR-8/SVneo)

Recently, a large number of long noncoding RNAs (lncRNAs) have been reported in human diseases that are evolutionarily conserved and are likely to play a role in many biological events including pre-eclampsia. In our previous research, we selected thousands of lncRNAs for their relationship with early-onset pre-eclampsia. Among these lncRNAs, a lncRNA named uc.294 attracted our attention, was once reported to specifically be expressed at a high level in the early-onset of pre-eclampsia. This study aims to investigate the function of uc.294 in early-onset pre-eclampsia and the possible mechanism. The uc.294 expression level in early-onset pre-eclampsia or in normal placenta tissues was evaluated by quantitative real-time polymerase chain reaction. To detect the proliferation, invasion, and apoptosis capacity of the trophoblast cells, we performed the Cell Counting Kit-8 assay, transwell assay, and flow cytometry, respectively. Here we report, for the first time, that uc.294 inhibits proliferation, invasion, and promotes apoptosis of trophoblast cells HTR-8/SVneo by working in key aspects of biological behaviors. However, how uc.294 acts to regulate gene functions in early-onset pre-eclampsia needs further exploration.     

Vimentin-mediated regulation of cell motility through modulation of beta4 integrin protein levels in oral tumor derived cells

Vimentin expression correlates well with migratory and invasive potential of the carcinoma cells. The molecular mechanism by which vimentin regulates cell motility is not yet clear. Here, we addressed this issue by depleting vimentin in oral squamous cell carcinoma derived cell line. Vimentin knockdown cells showed enhanced adhesion and spreading to laminin-5. However, we found that they were less invasive as compared to the vector control cells. In addition, signaling associated with adhesion behavior of the cell was increased in vimentin knockdown clones. These findings suggest that the normal function of β4 integrin as mechanical adhesive device is enhanced upon vimentin downregulation. As a proof of principle, the compromised invasive potential of vimentin depleted cells could be rescued upon blocking with β4 integrin adhesion-blocking (ASC-8) antibody or downregulation of β4 integrin in vimentin knockdown background. Interestingly, plectin which associates with α6β4 integrin in the hemidesmosomes, was also found to be upregulated in vimentin knockdown clones. Furthermore, experiments on lysosome and proteasome inhibition revealed that perhaps vimentin regulates the turnover of β4 integrin and plectin. Moreover, an inverse association was observed between vimentin expression and β4 integrin in oral squamous cell carcinoma (OSCC). Collectively, our results show a novel role of vimentin in modulating cell motility by destabilizing β4 integrin-mediated adhesive interactions. Further, vimentin-β4 integrin together may prove to be useful markers for prognostication of human oral cancer.