Previous studies have revealed the critical roles of N6-methyladenosine (m6A) modification of mRNA in embryonic stem cells (ESCs), but the biological function of m6A in large intergenic noncoding RNA (lincRNA) is unknown. Here, we showed that the internal m6A modification of linc1281 mediates a competing endogenous RNA (ceRNA) model to regulate mouse ESC (mESC) differentiation. We demonstrated that loss of linc1281 compromises mESC differentiation and that m6A is highly enriched within linc1281 transcripts. Linc1281 with RRACU m6A sequence motifs, but not an m6A-deficient mutant, restored the phenotype in linc1281-depleted mESCs. Mechanistic analyses revealed that linc1281 ensures mESC identity by sequestering pluripotency-related let-7 family microRNAs (miRNAs), and this RNA-RNA interaction is m6A dependent. Collectively, these findings elucidated the functional roles of linc1281 and its m6A modification in mESCs and identified a novel RNA regulatory mechanism, providing a basis for further exploration of broad RNA epigenetic regulatory patterns.
We developed an easy-traceable TRV vector, TRV2-GFP, by tagging a GFP to the coat protein. TRV2-GFP-infected plants could be identified efficiently by GFP monitoring. TRV2-GFP is useful for functional genomics in many plants, especially for non-Solanaceae plants, like rose
Aquaporins (AQPs) are multifunctional membrane channels and facilitate the transport of water across plant cell membranes. Among the plant AQPs, plasma membrane intrinsic proteins (PIPs), which cluster in two phylogenetic groups (PIP1 and PIP2), play a key role in plant growth. Our previous work has indicated that RhPIP2;1, a member of PIP2, is involved in ethylene-regulated cell expansion of rose petals. However, whether PIP1s also play a role in petal expansion is still unclear. Here, we identified RhPIP1;1, a PIP1 subfamily member, from 18 PIPs assemble transcripts in rose microarray database responsive to ethylene. RhPIP1;1 was rapidly and significantly down-regulated by ethylene treatment. RhETRs-silencing also clearly decreased the expression of RhPIP1;1 in rose petals. The activity of the RhPIP1;1 promoter was repressed by ethylene in rosettes and roots of Arabidopsis. RhPIP1;1 is mainly localized on endoplasmic reticulum and plasma membrane. We demonstrated that RhPIP1;1-silencing significantly inhibited the expansion of petals with decreased petal size and cell area, as well as reduced fresh weight when compared to controls. Expression of RhPIP1;1 in Xenopus oocytes indicated that RhPIP1;1 was inactive in terms of water transport, while coexpression of RhPIP1;1 with the functional RhPIP2;1 led to a significant increase in plasma membrane permeability. Yeast growth, β-Galactosidase activity, bimolecular fluorescence complementation, and colocalization assay proved existence of the interaction between RhPIP1;1 and RhPIP2;1. We argue that RhPIP1;1 plays an important role in ethylene-regulated petal cell expansion, at least partially through the interaction with RhPIP2;1.
Sarpagine-Ajmaline-Koumine type monoterpenoid indole alkaloids represent a fascinating class of natural products with polycyclic and cage-like structures, interesting biological activities, and related biosynthetic origins. Herein we report a unified approach towards the asymmetric synthesis of these three types of alkaloids, leading to a collective synthesis of 14 natural alkaloids. Among them, akuammidine, 19-Z-akuammidine, vincamedine, vincarine, quebrachidine, vincamajine, alstiphylianine J, and dihydrokoumine are accomplished for the first time. Features of our synthesis are a new Mannich-type cyclization to construct the key indole-fused azabicyclo[3.3.1]nonane common intermediate, a SmI2 mediated coupling to fuse the aza-bridged E-ring, stereoselective olefinations to install either the 19-E or 19-Z terminal alkenes presented in the natural alkaloids, and an efficient iodo-induced cyclization to establish the two vicinal all-carbon quaternary centers in the Koumine-type alkaloids.
Chronic inflammatory pain can induce emotional diseases. Electroacupuncture (EA) has effects on chronic pain and pain-related anxiety. Protein kinase Mzeta (PKMzeta) has been proposed to be essential for the maintenance of pain and may interact with GluR1 to maintain CNS plasticity in the anterior cingulate cortex (ACC). We hypothesized that the PKMzeta-GluR1 pathway in the ACC may be involved in anxiety-like behaviors of chronic inflammatory pain and that the mechanism of EA regulation of pain emotion may involve the PKMzeta pathway in the ACC. Our results showed that chronic inflammatory pain model decreased the paw withdrawal threshold (PWT) and increased anxiety-like behaviors. The protein expression of PKCzeta, p-PKCzeta (T560), PKMzeta, p-PKMzeta (T560), and GluR1 in the ACC of the model group were remarkably enhanced. EA increased PWT and alleviated anxiety-like behaviors. EA significantly inhibited the protein expression of p-PKMzeta (T560) in the ACC, and only a downward trend effect for other substances. Further, the microinjection of ZIP remarkably reversed PWT and anxiety-like behaviors. The present study provides direct evidence that the PKCzeta/PKMzeta-GluR1 pathway is related to pain and pain-induced anxiety-like behaviors. EA treatment both increases pain-related somatosensory behavior and decreases pain-induced anxiety-like behaviors by suppressing PKMzeta activity in the ACC.
In the present paper, a simple and facile method is proposed to synthesize Mo+C-codoped titanate (H 2 Ti 5 O 11 •3H 2 O) nanobelts by using hydrothermal method together with sol−gel technique, and various Mo-doped and Mo+Ccodoped titanate nanobelts are realized by controlling the precursor's contents. It is found that the photocatalytic activity of titanate nanobelts toward gaseous benzene will be greatly enhanced by Mo+C-codoping if comparing with that of the pure titanate nanobelts, Mo-doped titanate nanobelts, and C-doped titanate nanobelts, and the optimal Mo doping content is confirmed to be 0.33 wt % for Mo/Ti ratio. The reason lies in the fact that by Mo+C-codoping (Mo/Ti ratio of 0.33 wt %, C/Ti ratio of 0.33 wt %), the band gap of titanate nanobelts will be narrowed and the allowed paths for photoexcitation will be increased with the generation of impurity energy level, which results in an obvious red-shift in their UV−vis absorption spectra and the increased utilization of the solar energy, and thus enhances their photocatalytic activity. On the basis of the above experimental results, the current photocatalytic mechanism is proposed.
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