Identification of a novel MYOC mutation,p.(Trp373*), in a family with open angle glaucoma

MYOC gene variants are associated with autosomal dominant primary open angle glaucoma (POAG). In this study, we describe a previously unreported MYOC variant segregating with a POAG phenotype in an Australian family. Two individuals affected with POAG and three unaffected individuals from the same family were recruited through the Australian and New Zealand Registry of Advanced Glaucoma (ANZRAG). Direct sequencing of all MYOC coding exons identified the novel heterozygous single nucleotide transition MYOC:c.1119G>A, p.(Trp373*), predicted to encode an aberrant truncated MYOC protein in two affected siblings. Two unaffected siblings and an unaffected niece were negative for the MYOC sequence variant.     

Biophysical studies of eIF4E cap-binding protein: recognition of mRNA 5' cap structure and synthetic fragments of eIF4G and 4E-BP1 proteins

mRNA 5'-cap recognition by the eukaryotic translation initiation factor eIF4E has been exhaustively characterized with the aid of a novel fluorometric, time-synchronized titration method, and X-ray crystallography. The association constant values of recombinant eIF4E for 20 different cap analogues cover six orders of magnitude; with the highest affinity observed for m(7)GTP (approximately 1.1 x 10(8) M(-1)). The affinity of the cap analogues for eIF4E correlates with their ability to inhibit in vitro translation. The association constants yield contributions of non-covalent interactions involving single structural elements of the cap to the free energy of binding, giving a reliable starting point to rational drug design. The free energy of 7-methylguanine stacking and hydrogen bonding (-4.9 kcal/mol) is separate from the energies of phosphate chain interactions (-3.0, -1.9, -0.9 kcal/mol for alpha, beta, gamma phosphates, respectively), supporting two-step mechanism of the binding. The negatively charged phosphate groups of the cap act as a molecular anchor, enabling further formation of the intermolecular contacts within the cap-binding slot. Stabilization of the stacked Trp102/m(7)G/Trp56 configuration is a precondition to form three hydrogen bonds with Glu103 and Trp102. Electrostatically steered eIF4E-cap association is accompanied by additional hydration of the complex by approximately 65 water molecules, and by ionic equilibria shift. Temperature dependence reveals the enthalpy-driven and entropy-opposed character of the m(7)GTP-eIF4E binding, which results from dominant charge-related interactions (DeltaH degrees =-17.8 kcal/mol, DeltaS degrees= -23.6 cal/mol K). For recruitment of synthetic eIF4GI, eIF4GII, and 4E-BP1 peptides to eIF4E, all the association constants were approximately 10(7) M(-1), in decreasing order: eIF4GI>4E-BP1>eIF4GII approximately 4E-BP1(P-Ser65) approximately 4E-BP1(P-Ser65/Thr70). Phosphorylation of 4E-BP1 at Ser65 and Thr70 is insufficient to prevent binding to eIF4E. Enhancement of the eIF4E affinity for cap occurs after binding to eIF4G peptides.     

mRNA差别显示技术分离草菇低温诱导基因

本文报道采用改良的mRNA差别筛选法,通过选用3'锚定引物和18-25碱基的PCR随机引物组合,以琼脂糖凝胶电泳,EB显色替代聚丙烯酰胺凝胶电泳和放射自显影,对低温处理草菇(Volvariella volvacea)及正常草菇基因表达进行筛选、分析,结合RNA斑点杂交技术加以验证,分离得到70个草菇低温诱导DNA片段。     

EVI-1 modulates arsenic trioxide induced apoptosis through JNK signalling pathway in leukemia cells

High expression of the oncogene ecotropic viral integration site-1 (EVI-1) is an independent negative prognostic indicator of survival in leukemia patients. This study aimed to examine the effects of arsenic trioxide (ATO) on EVI-1 in acute myeloid leukemia (AML). Mononuclear cells were isolated from the bone marrow and peripheral blood of AML patients and healthy donors. EVI-1 expression in hematopoietic cells was evaluated by RT-qPCR and Western blot analysis. EVI-1 was highly expressed in both primary AML and leukemia cell lines (THP-1 and K562). ATO down-regulated EVI-1 mRNA in zebrafish in vivo as well as in primary leukemia cells and THP-1 and K562 cells in vitro. Additionally, ATO treatment induced apoptosis, down-regulated both EVI-1 mRNA and oncoprotein expression, increased the expression of pro-apoptosis proteins, and decreased the expression of anti-apoptotic proteins in leukemia cells in vitro. EVI-1 expression in leukemia cells (THP-1 and K562) transduced with EVI-1 siRNA was significantly reduced. Silencing EVI-1 had a significant effect on the activation of the JNK pathway and the induction of leukemia cell apoptosis. ATO may downregulate EVI-1 mRNA and oncoprotein levels and block the inhibitory effects of EVI-1 on the JNK pathway, which activates the JNK apoptotic pathway, thereby leading to the apoptosis of EVI-1 in AML patients.     

Effect of Photoperiod Treatments on Phytochrome a Levels and Its mRNA Abundance in Photoperiod-Sensitive Genic Male-Sterile Rice Mutant and the Wild Type

The effect of photoperiod treatments on phytochrome A (Phy A) level and its mRNA abundance in the leaves of a photoperiod-sensitive genic male-sterile mutant (Nongken 58S) and its wild type ("Nongken 58') of Oryza sativa L. was investigated. The top two leaves of each rice shoot were harvested at the end of the last dark phase of 10 cycles during photoperiod-sensitive stage for fertility alteration of the mutant. Phy A was measured by a sandwich enzyme-linked immunosorbent assay (ELISA) using rabbit polyclonal and mouse monoclonal antibodies. Compared with longday (LD) treatment,short day (SD) resulted in 38.5% increase of relative Phy A content in the mutant, only 18.5% increase in the wild type. In an extended darkness (25 h), the accumulation of Phy A also appeared to be more rapid in the mutant seedlings than in its wild type. RNA dot blot analyses with RPA3 (a cDNA clone of rice Phy A) as a probe showed:the abundances of Phy A mRNA in top leaves of Nongken 58S and "Nongken 58" were obviously higher in SD than those in ID at the end of dark phase of 5 d and 10 d photoperiod treatments. Moreover, under SD Phy A mRNA contents in Nongken 58S were more than those in "Nongken 58" during the whole photoperi- od-sensitive stage for fertility alteration. In addition, after 10 cycles of end-of-day far-red irradiations (EOD FR), the heading and flowering date of the mutant was delayed for 2 d. However, EOD FR had little or no effect on male fertility of the mutant.     

Backbone and sidechain methyl Ile (δ1), Leu and Val resonance assignments of the catalytic domain of the yeast mRNA decapping enzyme, Dcp2

Eukaryotic mRNA decapping by Dcp2 is the penultimate step in several mRNA decay pathways. To understand regulation of Dcp2 by ligand interactions, we have assigned the backbone and sidechain methyl Ile (δ1), Leu and Val chemical shifts of the catalytic domain of the S. Cerevisiae enzyme.