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Histone lysine demethylase 4D (KDM4D), also known as JMJD2D, plays an important role in cell proliferation and survival and has been associated with several tumor types. KDM4D has emerged as a potential target for the treatment of human cancer. Here, we reported crystal complex structures for two KDM4D inhibitors, OWS [2-(1 H -pyrazol-3-yl)isonicotinic acid] and 10r (5-hydroxy-2-methylpyrazolo[1,5-a]pyrido[3,2-e]pyrimidine-3-carbonitrile), which were both determined to 2.0 Å. OWS is a newly discovered KDM4D inhibitor (IC 50 = 4.28 μM) and the critical pharmacophores of this compound are confirmed by the complex structure. Compound 10r is a KDM4D inhibitor reported by us previously. To clarify the binding mode in more detail, the crystal structure was determined and the comparison analysis revealed unique interactions that had never been observed before. Overall, our data provide new structural insights for rational design and offer an opportunity for optimization of KDM4D inhibitors. • Crystal complex structures for two KDM4D inhibitors, OWS [2-(1 H -pyrazol-3-yl)isonicotinic acid] and 10r (5-hydroxy-2-methylpyrazolo[1,5-a]pyrido[3,2-e]pyrimidine-3-carbonitrile), were determined. • We report the discovery of a new KDM4D inhibitor, OWS, containing the 2-(1 H -pyrazol-3-yl)pyridine scaffold. • KDM4D- 10r complex structure reveals new details of protein-ligand interaction that have never been observed before. [ABSTRACT FROM AUTHOR]

Abstract AtNPF7.3/AtNRT1.5, which is a nitrate transporter that drives root-to-shoot transport of NO 3 −, is also involved in modulating the response to K+ deprivation in Arabidopsis by affecting root development and K+ transport. However, whether NPF7.3/NRT1.5 functions in regulating plant responses to deficiencies of other nutrients remains unknown. In this study, we found that the expression of AtNPF7.3/AtNRT1.5 was predominant in the roots and was substantially induced by phosphate (Pi) starvation. The atnrt1.5 mutants displayed conspicuously longer primary roots along with a significantly reduced lateral root density under Pi-deficient conditions than did the wild-type plants, and these morphological differences in the roots were eliminated to a certain extent by the ethylene synthesis antagonist Co2+. Further analyses revealed that the expression of important Pi starvation-induced genes, which are directly involved in Pi transport, mobilization and distribution, were significantly higher in the atnrt1.5 mutants than that in the wild-type plants under Pi-starvation conditions; therefore, the atnrt1.5 mutants retained higher tissue Pi concentrations. Taken together, our results suggest that NPF7.3/NRT1.5 is an important component in the regulation of phosphate deficiency responses in Arabidopsis. Highlights • Expression of NRT1.5 was strongly induced by Pi-starvation. • Nrt1.5 mutants displayed altered root architecture under Pi-deficiency. • Nrt1.5 mutants might lose the ethylene responsiveness under Pi-deficiency. • The mutation of NRT1.5 enhanced the expression of Pi starvation-induced genes. • The mutation of NRT1.5 increased the tissue Pi content under Pi-deficiency. [ABSTRACT FROM AUTHOR]

Abstract: Modulation on the duration of intracellular Ca2+ transients is essential for B-cell activation. We have previously shown that extracellular-signal-regulated kinase (ERK) can phosphorylate inositol 1,4,5-trisphosphate receptor type 1 (IP3R1) at serine 436 and regulate its calcium channel activity. Here we investigate the potential physiological interaction between ERK and IP3R1 using chicken DT40 B-cell line in which different mutants are expressed. The interaction between ERK and IP3R1 is confirmed by co-immunoprecipitation and fluorescence resonance energy transfer (FRET) assays. This constitutive interaction is independent of either ERK kinase activation or IP3R1 phosphorylation status. Back phosphorylation analysis further shows that type 1 IP3R (IP3R1) is phosphorylated by ERK in anti-IgM-activated DT40 cells. Finally, our data show that the phosphorylation of Ser 436 in the IP3-binding domain of IP3R1 leads to less Ca2+ release from endoplasmic reticulum (ER) microsomes and accelerates the declining of calcium increase in DT40 cells in response to anti-IgM stimulation. [Copyright &y& Elsevier]

Abstract: Type 1 inositol 1,4,5-trisphosphate receptor (IP3R1) is a widely expressed intracellular calcium-release channel found in many cell types. The operation of IP3R1 is regulated through phosphorylation by multiple protein kinases. Extracellular signal-regulated kinase (ERK) has been found involved in calcium signaling in distinct cell types, but the underlying mechanisms remain unclear. Here, we present evidence that ERK1/2 and IP3R1 bind together through an ERK binding motif in mouse cerebellum in vivo as well as in vitro. ERK-phosphorylating serines (Ser 436) was identified in mouse IP3R1 and Ser 436 phosphorylation had a suppressive effect on IP3 binding to the recombinant N-terminal 604-amino acid residues (N604). Moreover, phosphorylation of Ser 436 in R(224–604) evidently enhance its interaction with the N-terminal “suppressor” region (N223). At last, our data showed that Ser 436 phosphorylation in IP3R1 decreased Ca2+ releasing through IP3R1 channels. [Copyright &y& Elsevier]

Abstract: It has been shown recently that hyperplasia suppressor gene (HSG) is a powerful regulator for cell proliferation and has a critical role in mitochondrial fusion in many cells. However, little is known about its expression, localization, and function during oocyte maturation and early embryogenesis. In this study, with indirect immunofluorescent staining and Western blotting, we found that HSG was expressed in mouse oocytes and preimplantation embryos which primarily exhibited a submembrane distribution pattern in the cytoplasm. Moreover, HSG mainly associated with β-tubulin during oocyte maturation and early embryonic development. When mouse zygotes were injected with HSG antisense plasmid and cultured in vitro, their capacity to form blastocysts was severely impaired. Our results indicate that HSG plays an essential role in mouse preimplantation development. [Copyright &y& Elsevier]

Abstract: Mammalian freeze-dried sperm can maintain their genetic integrity and event support full development to term when microinjected into mature oocytes. However, it is unknown whether freeze-dried sperm can still maintain their calcium oscillation-inducing capability. Here, we microinjected mouse and bovine freeze-dried sperm into mouse MII oocytes and examined their calcium oscillation-inducing ability following intracytoplasmic sperm injection (ICSI). Two pieces of information are revealed. First, nearly all oocytes injected with a freeze-dried mouse sperm head or a bovine sperm showed fertilization-like calcium oscillations, indicating that freeze-drying treatment does not affect the activity of the sperm factor responsible for calcium oscillations. Second, freeze-dried sperm exhibited high resistance to external temperature increase. This is shown by the finding that the freeze-dried sperm can maintain their calcium oscillation-inducing capacity even following exposure to 100°C for 3h. We therefore conclude that mammalian sperm can maintain their calcium oscillation-inducing capability following freeze-drying, rehydration, and ICSI treatments. [Copyright &y& Elsevier]