Adverse Effect of Metallic Gold and Silver Nanoparticles on Embryogenesis.

Exposure to metal nanoparticles is potentially harmful, particularly when occurring during embryogenesis. In this study, we tested the effects of commercial AuNPs and AgNPs, widely used in many fields for their features, on the early development of , an anuran amphibian key model species in toxicity testing. Through the Frog Embryo Teratogenesis Assay- test (FETAX), we ascertained that both nanoparticles did not influence the survival rate but induced morphological anomalies like modifications of head and branchial arch cartilages, depigmentation of the dorsal area, damage to the intestinal brush border, and heart rate alteration.

A signalling cascade involving receptor-activated phospholipase A, glycerophosphoinositol 4-phosphate, Shp1 and Src in the activation of cell motility.

Background: Shp1, a tyrosine-phosphatase-1 containing the Src-homology 2 (SH2) domain, is involved in inflammatory and immune reactions, where it regulates diverse signalling pathways, usually by limiting cell responses through dephosphorylation of target molecules. Moreover, Shp1 regulates actin dynamics. One Shp1 target is Src, which controls many cellular functions including actin dynamics.

Golgi membrane fission requires the CtBP1-S/BARS-induced activation of lysophosphatidic acid acyltransferase δ.

Membrane fission is an essential cellular process by which continuous membranes split into separate parts. We have previously identified CtBP1-S/BARS (BARS) as a key component of a protein complex that is required for fission of several endomembranes, including basolateral post-Golgi transport carriers. Assembly of this complex occurs at the Golgi apparatus, where BARS binds to the phosphoinositide kinase PI4KIIIβ through a 14-3-3γ dimer, as well as to ARF and the PKD and PAK kinases.

Light signaling controls nuclear architecture reorganization during seedling establishment.

The spatial organization of chromatin can be subject to extensive remodeling in plant somatic cells in response to developmental and environmental signals. However, the mechanisms controlling these dynamic changes and their functional impact on nuclear activity are poorly understood. Here, we determined that light perception triggers a switch between two different nuclear architectural schemes during Arabidopsis postembryonic development.

Golgi sorting regulates organization and activity of GPI proteins at apical membranes.

Here we combined classical biochemistry with new biophysical approaches to study the organization of glycosylphosphatidylinositol (GPI)-anchored proteins (GPI-APs) with high spatial and temporal resolution at the plasma membrane of polarized epithelial cells. We show that in polarized MDCK cells, after sorting in the Golgi, each GPI-AP reaches the apical surface in homoclusters. Golgi-derived homoclusters are required for their subsequent plasma membrane organization into cholesterol-dependent heteroclusters.

Ribonuclease/angiogenin inhibitor 1 regulates stress-induced subcellular localization of angiogenin to control growth and survival.

Angiogenin (ANG) promotes cell growth and survival. Under growth conditions, ANG undergoes nuclear translocation and accumulates in the nucleolus where it stimulates rRNA transcription. When cells are stressed, ANG mediates the production of tRNA-derived stress-induced small RNA (tiRNA), which reprograms protein translation into a survival mechanism.

A 14-3-3γ dimer-based scaffold bridges CtBP1-S/BARS to PI(4)KIIIβ to regulate post-Golgi carrier formation.

Large pleiomorphic carriers leave the Golgi complex for the plasma membrane by en bloc extrusion of specialized tubular domains, which then undergo fission. Several components of the underlying molecular machinery have been identified, including those involved in the budding/initiation of tubular carrier precursors (for example, the phosphoinositide kinase PI(4)KIIIβ, the GTPase ARF, and FAPP2), and in the fission of these precursors (for example, PKD, CtBP1-S/BARS). However, how these proteins interact to bring about carrier formation is poorly understood.

MiR-34a targeting of Notch ligand delta-like 1 impairs CD15+/CD133+ tumor-propagating cells and supports neural differentiation in medulloblastoma.

Background: Through negative regulation of gene expression, microRNAs (miRNAs) can function as oncosuppressors in cancers, and can themselves show altered expression in various tumor types. Here, we have investigated medulloblastoma tumors (MBs), which arise from an early impairment of developmental processes in the cerebellum, where Notch signaling is involved in many of the cell-fate-determining stages. Notch regulates a subset of MB cells that have stem-cell-like properties and can promote tumor growth.

Preferential nuclear accumulation of JAK2V617F in CD34+ but not in granulocytic, megakaryocytic, or erythroid cells of patients with Philadelphia-negative myeloproliferative neoplasia.

Recently, Dawson et al identified a previously unrecognized nuclear role of JAK2 in the phosphorylation of histone H3 in hematopoietic cell lines. We searched nuclear JAK2 in total bone marrow (BM) cells and in 4 sorted BM cell populations (CD34(+), CD15(+), CD41(+), and CD71(+)) of 10 myeloproliferative neoplasia (MPN) patients with JAK2V617F mutation and 5 patients with wild-type JAK2 MPN. Confocal immunofluorescent images and Western blot analyses of nuclear and cytoplasmic fractions found nuclear JAK2 in CD34(+) cells of 10 of 10 JAK2-mutated patients but not in patients with wild-type JAK2.

A stress surveillance system based on calcium and nitric oxide in marine diatoms.

Diatoms are an important group of eukaryotic phytoplankton, responsible for about 20% of global primary productivity. Study of the functional role of chemical signaling within phytoplankton assemblages is still in its infancy although recent reports in diatoms suggest the existence of chemical-based defense strategies. Here, we demonstrate how the accurate perception of diatom-derived reactive aldehydes can determine cell fate in diatoms.

The photomorphogenesis regulator DET1 binds the amino-terminal tail of histone H2B in a nucleosome context.

Light provides a major source of information from the environment during plant growth and development. Recent results suggest that the key events controlling light-regulated gene expression in plants are translocation of the phytochrome photoreceptors into the nucleus, followed by their binding to transcription factors such as PIF3. Coupled with this, the degradation of positively acting intermediates such as the transcription factor HY5 by COP1 and the COP9 signalosome appears to be an important process whereby photomorphogenesis is repressed in darkness (e.