Analysis of essential pathways for self-renewal in common marmoset embryonic stem cells
In this study, we found that basic fibroblast growth factor (bFGF) rather than leukemia inhibitory factor (LIF) promoted CM ESC self-renewal via the activation of phosphatidylinositol-3-kinase (PI3K)-protein kinase B (AKT) pathway on mouse embryonic fibroblast (MEF) feeders. Moreover, bFGF and transforming growth factor β (TGFβ) signaling pathways cooperatively maintained the undifferentiated state of CM ESCs under feeder-free condition. Our findings may improve the culture techniques of CM ESCs and facilitate their use as a preclinical experimental resource for human regenerative medicine. (Source: FEBS Open Bio)
Source: FEBS Open Bio - October 12, 2014 Category: Molecular Biology Source Type: research
Similarities and differences in the biochemical and enzymological properties of the four isomaltases from Saccharomyces cerevisiae
Publication date: 2014 Source:FEBS Open Bio, Volume 4 Author(s): Xu Deng , Marjorie Petitjean , Marie-Ange Teste , Wafa Kooli , Samuel Tranier , Jean Marie François , Jean-Luc Parrou The yeast Saccharomyces cerevisiae IMA multigene family encodes four isomaltases sharing high sequence identity from 65% to 99%. Here, we explore their functional diversity, with exhaustive in-vitro characterization of their enzymological and biochemical properties. The four isoenzymes exhibited a preference for the α-(1,6) disaccharides isomaltose and palatinose, with Michaëlis–Menten kinetics and inhibition at high substrates...
Source: FEBS Open Bio - October 12, 2014 Category: Molecular Biology Source Type: research
Fixation-induced cell blebbing on spread cells inversely correlates with phosphatidylinositol 4,5-bisphosphate level in the plasma membrane
Publication date: 2014 Source:FEBS Open Bio, Volume 4 Author(s): Siyuan Zhao , Huanhuan Liao , Meiying Ao , Li Wu , Xiaojun Zhang , Yong Chen While most attention has been focused on physiologically generated blebs, the molecular mechanisms for fixation-induced cell blebbing are less investigated. We show that protein-fixing (e.g. aldehydes and picric acid) but not lipid-stabilizing (e.g. OsO4 and KMnO4) fixatives induce blebbing on spread cells. We also show that aldehyde fixation may induce the loss or delocalization of phosphatidylinositol 4,5-bisphosphate (PIP2) in the plasma membrane and that the asymmetric ...
Source: FEBS Open Bio - October 12, 2014 Category: Molecular Biology Source Type: research
Survey and analysis of simple sequence repeats (SSRs) present in the genomes of plant viroids
Publication date: 2014 Source:FEBS Open Bio, Volume 4 Author(s): Lü Qin , Zhixiang Zhang , Xiangyan Zhao , Xiaolong Wu , Yubao Chen , Zhongyang Tan , Shifang Li Extensive simple sequence repeat (SSR) surveys have been performed for eukaryotic prokaryotic and viral genomes, but information regarding SSRs in viroids is limited. We undertook a survey to examine the presence of SSRs in viroid genomes. Our results show that the distribution of SSRs in viroids may influence secondary structure, and that SSRs could play a role in generating genetic diversity. We also discuss the potential evolutionary role of repeated...
Source: FEBS Open Bio - October 12, 2014 Category: Molecular Biology Source Type: research
Detection of changes in the structure and distribution map of triacylglycerol in fatty liver model by MALDI-SpiralTOF
Publication date: 2014 Source:FEBS Open Bio, Volume 4 Author(s): Kahoko Nishikawa , Masahiro Hashimoto , Yoshiyuki Itoh , Sadayuki Hiroi , Akihiko Kusai , Fumihiko Hirata , Toshihisa Sakamoto , Keiichi Iwaya Matrix-assisted laser desorption/ionisation spiral orbit-type time-of-flight mass spectrometry (MALDI-SpiralTOF) can analyse lipid profiles and characterise lipid structure. Imaging mass spectrometry (IMS) also provides distribution maps of selected m/z values. Here, we investigated triacylglycerol (TG) structure and distribution using these technologies to estimate mouse fatty liver. The distribution and i...
Source: FEBS Open Bio - October 12, 2014 Category: Molecular Biology Source Type: research
Origin and evolution of the Peptidyl Transferase Center from proto-tRNAs
Publication date: 2014 Source:FEBS Open Bio, Volume 4 Author(s): Sávio T. Farias , Thais G. Rêgo , Marco V. José We tested the hypothesis of Tamura (2011) [3] that molecules of tRNA gave origin to ribosomes, particularly to the Peptidyl Transferase Center (PTC) of the 23S ribosomal RNA. We reconstructed the ancestral sequences from all types of tRNA and compared them in their sequences with the current PTC of 23S ribosomal RNA from different organisms. We built an ancestral sequence of proto-tRNAs that showed a remarkable overall identity of 50.53% with the catalytic site of PTC. We conclude that the Peptidyl Tra...
Source: FEBS Open Bio - October 12, 2014 Category: Molecular Biology Source Type: research
Stabilization of cyclohexanone monooxygenase by a computationally designed disulfide bond spanning only one residue
This study shows that stabilizing disulfide bonds do not have to span many residues, as the most stabilizing disulfide bond, L323C–A325C, spans only one residue while it stabilizes the enzyme, as shown by a 6°C increase in its apparent melting temperature. (Source: FEBS Open Bio)
Source: FEBS Open Bio - October 12, 2014 Category: Molecular Biology Source Type: research
Identification of myo-inositol hexakisphosphate (IP6) as a β-secretase 1 (BACE1) inhibitory molecule in rice grain extract and digest
Publication date: 2014 Source:FEBS Open Bio, Volume 4 Author(s): Takako K. Abe , Masayuki Taniguchi Alzheimer’s disease (AD) is widely considered to be caused by amyloid-β peptide (Aβ) accumulation in the brain. Aβ is excised from amyloid-β precursor protein through sequential cleavage by β-secretase 1 (BACE1) and γ-secretase. Thus, BACE1 inhibition could prevent Aβ accumulation. Here, we identified myo-inositol hexakisphosphate (IP6) as a BACE1 inhibitory molecule in rice grain extract and digest. The rice digest and IP6 significantly inhibited Aβ production in neuroblastoma cells without cytotoxicity. The...
Source: FEBS Open Bio - October 12, 2014 Category: Molecular Biology Source Type: research
A novel cell-penetrating peptide derived from WT1 enhances p53 activity, induces cell senescence and displays antimelanoma activity in xeno- and syngeneic systems
Publication date: 2014 Source:FEBS Open Bio, Volume 4 Author(s): Mariana H. Massaoka , Alisson L. Matsuo , Carlos R. Figueiredo , Natalia Girola , Camyla F. Faria , Ricardo A. Azevedo , Luiz R. Travassos The Wilms tumor protein 1 (WT1) transcription factor has been associated in malignant melanoma with cell survival and metastasis, thus emerging as a candidate for targeted therapy. A lysine–arginine rich peptide, WT1-pTj, derived from the ZF domain of WT1 was evaluated as an antitumor agent against A2058 human melanoma cells and B16F10-Nex2 syngeneic murine melanoma. Peptide WT1-pTj quickly penetrated human me...
Source: FEBS Open Bio - October 12, 2014 Category: Molecular Biology Source Type: research
The VTLISFG motif in the BH1 domain plays a significant role in regulating the degradation of Mcl-1
Publication date: 2014 Source:FEBS Open Bio, Volume 4 Author(s): Kang Xiao , Pengxuan Chen , Donald Choy Chang Mcl-1 is a member of the Bcl-2 family protein; its degradation is required for the initiation of apoptosis. The mechanism, however, is not yet clearly known. Previously, it was reported that Mcl-1 is degraded through the ubiquitination-mediated pathway and the PEST domain is the motif responsible for promoting this degradation. We found evidence that this may not be true. We generated several Mcl-1 deletion mutants and examined their effects on protein stability. Deletion of the PEST domain did not prevent ...
Source: FEBS Open Bio - October 12, 2014 Category: Molecular Biology Source Type: research
DHEA supplementation in ovariectomized rats reduces impaired glucose-stimulated insulin secretion induced by a high-fat diet
Publication date: 2014 Source:FEBS Open Bio, Volume 4 Author(s): Katherine Veras , Felipe Natali Almeida , Renato Tadeu Nachbar , Daniel Simões de Jesus , João Paulo Camporez , Ângelo Rafael Carpinelli , Julia H. Goedecke , Carla Roberta de Oliveira Carvalho Dehydroepiandrosterone (DHEA) and the dehydroepiandrosterone sulfate (DHEA-S) are steroids produced mainly by the adrenal cortex. There is evidence from both human and animal models suggesting beneficial effects of these steroids for obesity, diabetes mellitus, hypertension, and osteoporosis, conditions associated with the post-menopausal period. Accordi...
Source: FEBS Open Bio - October 12, 2014 Category: Molecular Biology Source Type: research
Integrated mRNA and microRNA transcriptome sequencing characterizes sequence variants and mRNA–microRNA regulatory network in nasopharyngeal carcinoma model systems
Publication date: 2014 Source:FEBS Open Bio, Volume 4 Author(s): Carol Ying-Ying Szeto , Chi Ho Lin , Siu Chung Choi , Timothy T.C. Yip , Roger Kai-Cheong Ngan , George Sai-Wah Tsao , Maria Li Lung Nasopharyngeal carcinoma (NPC) is a prevalent malignancy in Southeast Asia among the Chinese population. Aberrant regulation of transcripts has been implicated in many types of cancers including NPC. Herein, we characterized mRNA and miRNA transcriptomes by RNA sequencing (RNASeq) of NPC model systems. Matched total mRNA and small RNA of undifferentiated Epstein–Barr virus (EBV)-positive NPC xenograft X666 and its d...
Source: FEBS Open Bio - October 12, 2014 Category: Molecular Biology Source Type: research
Ancestral mutations as a tool for solubilizing proteins: The case of a hydrophobic phosphate-binding protein
We describe a simple and fast method that selectively uses ancestral mutations to generate a soluble, stable and functional variant of the target protein, here named sHPBP. This variant is highly expressed in Escherichia coli, is easily purified and its structure was solved at much higher resolution than its wild-type progenitor (1.3 versus 1.9 Å, respectively). (Source: FEBS Open Bio)
Source: FEBS Open Bio - October 12, 2014 Category: Molecular Biology Source Type: research
The role of Importin-βs in the maintenance and lineage commitment of mouse embryonic stem cells
Publication date: 2014 Source:FEBS Open Bio, Volume 4 Author(s): Percival Sangel , Masahiro Oka , Yoshihiro Yoneda Members of the Importin-β family recognize nuclear localization signals (NLS) and nuclear export signals (NES). These proteins play important roles in various nucleocytoplasmic transport processes in cells. Here, we examined the expression patterns of 21 identified Importin-β genes in mouse embryonic stem cells (mESCs), mouse embryonic fibroblast (MEF) and mESCs differentiated into neural ectoderm (NE) or mesoendoderm (ME). We observed striking differences in the Importin-β mRNA expression levels wit...
Source: FEBS Open Bio - October 12, 2014 Category: Molecular Biology Source Type: research
Understanding the mechanism of glucose-induced relief of Rgt1-mediated repression in yeast
In this study, using Rgt1 chimeras that bind DNA constitutively, we investigate how glucose regulates Rgt1 function. Our results show that the DNA-bound Rgt1 constructs repress expression of the HXT1 gene in conjunction with Ssn6-Tup1 and Mth1, and that this repression is lifted when they dissociate from Ssn6-Tup1 in high glucose conditions. Mth1 mediates the interaction between the Rgt1 constructs and Ssn6-Tup1, and glucose-induced downregulation of Mth1 enables PKA to phosphorylate the Rgt1 constructs. This phosphorylation induces dissociation of Ssn6-Tup1 from the DNA-bound Rgt1 constructs, resulting in derepression of ...
Source: FEBS Open Bio - October 12, 2014 Category: Molecular Biology Source Type: research
