Light controls stamen elongation via cryptochromes,phytochromes and COP1 through HY5 and HYH

In Arabidopsis, stamen elongation, which ensures male fertility, is controlled by the auxin response factor ARF8, which regulates the expression of the auxin repressor IAA19. Here, we uncover a role for light in controlling stamen elongation. By an extensive genetic and molecular analysis we show that the repressor of light signaling COP1, through its targets HY5 and HYH, controls stamen elongation, and that HY5 – oppositely to ARF8 – directly represses the expression of IAA19 in stamens. In addition, we show that in closed flower buds, when light is shielded by sepals and petals, the blue light receptors CRY1/CRY2 repress stamen elongation. Coherently, at flower disclosure and in subsequent stages, stamen elongation is repressed by the red and far‐red light receptors PHYA/PHYB. In conclusion, different light qualities – sequentially perceived by specific photoreceptors – and the downstream COP1–HY5/HYH module finely tune auxin‐induced stamen elongation and thus male fertility.     

Correction to: Comparative analysis of sperm motility in liquid and seminal coagulum portions between Bornean orangutan (Pongo pygmaeus) and chimpanzee (Pan troglodytes)

Primates - In the original publication of the article, the coauthor “Takashi Hayakawa” was wrongly assigned as co-corresponding author.     

Molecular characterization of mouse CREB3 regulatory factor in Neuro2a cells

We performed expression and functional analysis of mouse CREB3 regulatory factor (CREBRF) in Neuro2a cells by constructing several expression vectors. Overexpressed full-length (FL) CREBRF protein was stabilized by MG132; however, the intrinsic CREBRF expression in Neuro2a cells was negligible under all conditions. On the other hand, N- or C-terminal deletion of CREBRF influenced its stability. Cotransfection of CREBRF together with GAL4-tagged FL CREB3 increased luciferase reporter activity, and only the N-terminal region of CREBRF was sufficient to potentiate luciferase activity. Furthermore, this positive effect of CREBRF was also observed in cells expressing GAL4-tagged cleaved CREB3, although CREBRF hardly influenced the protein stability of NanoLuc-tagged cleaved CREB3 or intracellular localization of EGFP-tagged one. In conclusion, this study suggests that CREBRF, a quite unstable proteasome substrate, positively regulates the CREB3 pathway, which is distinct from the canonical ER stress pathway in Neuro2a cells.

     

Aurora B switches relative strength of kinetochore–microtubule attachment modes for error correction

To establish chromosome biorientation, aberrant kinetochore–microtubule interaction must be resolved (error correction) by Aurora B kinase. Aurora B differentially regulates kinetochore attachment to the microtubule plus end and its lateral side (end-on and lateral attachment, respectively). However, it is still unclear how kinetochore–microtubule interactions are exchanged during error correction. Here, we reconstituted the budding yeast kinetochore–microtubule interface in vitro by attaching the Ndc80 complexes to nanobeads. These Ndc80C nanobeads recapitulated in vitro the lateral and end-on attachments of authentic kinetochores on dynamic microtubules loaded with the Dam1 complex. This in vitro assay enabled the direct comparison of lateral and end-on attachment strength and showed that Dam1 phosphorylation by Aurora B makes the end-on attachment weaker than the lateral attachment. Similar reconstitutions with purified kinetochore particles were used for comparison. We suggest the Dam1 phosphorylation weakens interaction with the Ndc80 complex, disrupts the end-on attachment, and promotes the exchange to a new lateral attachment, leading to error correction.     

Accuracy of specimen-specific nonlinear finite element analysis for evaluation of radial diaphysis strength in cadaver material

The feasibility of a user-specific finite element model for predicting the in situ strength of the radius after implantation of bone plates for open fracture reduction was established. The effect of metal artifact in CT imaging was characterized. The results were verified against biomechanical test data. Fourteen cadaveric radii were divided into two groups: (1) intact radii for evaluating the accuracy of radial diaphysis strength predictions with finite element analysis and (2) radii with a locking plate affixed for evaluating metal artifact. All bones were imaged with CT. In the plated group, radii were first imaged with the plates affixed (for simulating digital plate removal). They were then subsequently imaged with the locking plates and screws removed (actual plate removal). Fracture strength of the radius diaphysis under axial compression was predicted with a three-dimensional, specimen-specific, nonlinear finite element analysis for both the intact and plated bones (bones with and without the plate captured in the scan). Specimens were then loaded to failure using a universal testing machine to verify the actual fracture load. In the intact group, the physical and predicted fracture loads were strongly correlated. For radii with plates affixed, the physical and predicted (simulated plate removal and actual plate removal) fracture loads were strongly correlated. This study demonstrates that our specimen-specific finite element analysis can accurately predict the strength of the radial diaphysis. The metal artifact from CT imaging was shown to produce an overestimate of strength.     

Induction of GPR40 positively regulates cell motile and growth activities in breast cancer MCF-7 cells

Abstract

Free fatty acid (FFA) receptors belong to a member of G-protein-coupled receptors. GPCR 120 (GPR120) and GPR40 are identified as FFA receptors and activated via the binding of long- and medium-chain FFAs. The aim of this study was to assess the effects of GPR120 and GPR40 on cell motility and growth in breast cancer cells treated with tamoxifen (TAM). MCF-7 cells were continuously treated with TAM for approximately 6?months. The expression level of GPR40 gene was markedly higher in the long-term TAM treated (MCF-TAM) cells than in MCF-7 cells. In cell motility assay, MCF-TAM cells indicated the high cell motile activity, compared with MCF-7 cells. The cell motile activity of MCF-TAM cells was suppressed by a selective GPR40 antagonist, GW1100. To evaluate the effects of GPR40 on cell growth activity under estrogen-free conditions, cells were maintained in serum-free DMEM without phenol red for 2?days. In estrogen-free conditioned medium, the cell growth rate of MCF-TAM cells was significantly higher than that of MCF-7 cells. In addition, treatment of GW1100 reduced the cell growth rate of MCF-TAM cells. These results suggest that the cell motile and growth activities may be positively regulated through the induction of GPR40 by the long-term TAM treatment in MCF-7 cells.     

Inhibition of Influenza Virus Replication by Phosphorothioate and Liposomally Endocapsulated Oligonucleotides

Abstract

We have demonstrated that antisense phosphorothioate oligonucleotides (S-ODNs) inhibit influenza virus A replication in MDCK cells. Phosphorothioate and liposomally encapsulated oligonucleotides with two target sites (PB1 and PB2) were synthesized and tested for virus-induced cytopathogenicity effects by a MTT assay using MDCK cells. The liposomally encapsulated S-ODNs complementary to the sites of the PB2-AUG initiation codon showed highly inhibitory effects. On the other hand, the inhibitory effect of the liposomally encapsulated S-ODNs targeted to PB1 was considerably decreased in comparison with the PB2 target sites. The liposomally encapsulated oligonucleotides exhibited higher inhibitory activity than the free oligonucleotides. The activities of the modified oligonucleotides are effectively enhanced by using the liposomal carrier.