Screening of optimal cellulases from symbiotic protists of termites through expression in the secretory pathway of Saccharomyces cerevisiae

For direct and efficient ethanol production from cellulosic materials, we screened optimal cellulases from symbiotic protists of termites through heterologous expression with Saccharomyces cerevisiae. 11 cellulases, belonging to glycoside hydrolase families 5, 7, and 45 endoglucanases (EGs), were confirmed to produce with S. cerevisiae for the first time. A recombinant yeast expressing SM2042B24 EG I was more efficient at degrading carboxylmethyl cellulose than was Trichoderma reesei EG I, a major EG with high cellulolytic activity.     

Characterization of a loss-of-function mutant of gibberellin biosynthetic gene LsGA3ox1 in lettuce

A previous study generated lettuce (Lactuca sativa) mutant lines tagged by retrotransposon Tnt1 from tobacco (Nicotiana tabacum) and identified a homozygous mutant, Tnt6a, that exhibited severe dwarf phenotype. Here we show that Tnt1 is inserted into the intron of gibberellin biosynthetic gene LsGA3ox1 in Tnt6a mutants. Expression analysis suggests that LsGA3ox1 is nearly knocked out in the Tnt6a mutants.     

RP58 Regulates the Multipolar-Bipolar Transition of Newborn Neurons in the Developing Cerebral Cortex

1. Download : Download full-size image

Highlights? RP58 regulates neuronal migration independently of cell cycle exit ? RP58 is involved in the regulation of axonal and dendritic development ? RP58 is essential for multipolar-to-bipolar transition of neurons ? RP58 controls neuronal migration by regulating the Ngn2-Rnd2 pathway     

Generation of Rejuvenated Antigen-Specific T Cells by Reprogramming to Pluripotency and Redifferentiation

1. Download : Download high-res image (318KB)
2. Download : Download full-size image

Highlights? Reprogramming of antigen-specific T cells to generate iPSCs (T-iPSCs) ? Redifferentiation of CD8⁺ T cells, with original antigen specificity, from T-iPSCs ? Newly differentiated T cells show high proliferation and elongated telomeres ? T cell antigen-specific cytotoxicity is maintained     

Metabolic changes in a pyruvate kinase gene deletion mutant of Corynebacterium glutamicum ATCC 13032

To investigate primary effects of a pyruvate kinase (PYK) defect on glucose metabolism in Corynebacterium glutamicum, a pyk-deleted mutant was derived from wild-type C. glutamicum ATCC13032 using the double-crossover chromosome replacement technique. The mutant was then evaluated under glutamic acid-producing conditions induced by biotin limitation. The mutant showed an increased specific rate of glucose consumption, decreased growth, higher glutamic acid production, and aspartic acid formation during the glutamic acid production phase. A significant increase in phosphoenolpyruvate (PEP) carboxylase activity and a significant decrease in PEP carboxykinase activity occurred in the mutant, which suggested an enhanced overall flux of the anaplerotic pathway from PEP to oxaloacetic acid in the mutant. The enhanced anaplerotic flux may explain both the increased rate of glucose consumption and the higher productivity of glutamic acid in the mutant. Since the pyk-complemented strain had similar metabolic profiles to the wild-type strain, the observed changes represented intrinsic effects of pyk deletion on the physiology of C. glutamicum.     

Natural Forest Biomass Estimation Based on Plantation Information Using PALSAR Data

Forests play a vital role in terrestrial carbon cycling; therefore, monitoring forest biomass at local to global scales has become a challenging issue in the context of climate change. In this study, we investigated the backscattering properties of Advanced Land Observing Satellite (ALOS) Phased Array L-band Synthetic Aperture Radar (PALSAR) data in cashew and rubber plantation areas of Cambodia. The PALSAR backscattering coefficient (σ⁰) had different responses in the two plantation types because of differences in biophysical parameters. The PALSAR σ⁰ showed a higher correlation with field-based measurements and lower saturation in cashew plants compared with rubber plants. Multiple linear regression (MLR) models based on field-based biomass of cashew (C-MLR) and rubber (R-MLR) plants with PALSAR σ⁰ were created. These MLR models were used to estimate natural forest biomass in Cambodia. The cashew plant-based MLR model (C-MLR) produced better results than the rubber plant-based MLR model (R-MLR). The C-MLR-estimated natural forest biomass was validated using forest inventory data for natural forests in Cambodia. The validation results showed a strong correlation (R² = 0.64) between C-MLR-estimated natural forest biomass and field-based biomass, with RMSE  = 23.2 Mg/ha in deciduous forests. In high-biomass regions, such as dense evergreen forests, this model had a weaker correlation because of the high biomass and the multiple-story tree structure of evergreen forests, which caused saturation of the PALSAR signal.     

Sex Differences in the Rapid Detection of Emotional Facial Expressions

Background

Previous studies have shown that females and males differ in the processing of emotional facial expressions including the recognition of emotion, and that emotional facial expressions are detected more rapidly than are neutral expressions. However, whether the sexes differ in the rapid detection of emotional facial expressions remains unclear.

Methodology/Principal Findings

We measured reaction times (RTs) during a visual search task in which 44 females and 46 males detected normal facial expressions of anger and happiness or their anti-expressions within crowds of neutral expressions. Anti-expressions expressed neutral emotions with visual changes quantitatively comparable to normal expressions. We also obtained subjective emotional ratings in response to the facial expression stimuli. RT results showed that both females and males detected normal expressions more rapidly than anti-expressions and normal-angry expressions more rapidly than normal-happy expressions. However, females and males showed different patterns in their subjective ratings in response to the facial expressions. Furthermore, sex differences were found in the relationships between subjective ratings and RTs. High arousal was more strongly associated with rapid detection of facial expressions in females, whereas negatively valenced feelings were more clearly associated with the rapid detection of facial expressions in males.

Conclusion

Our data suggest that females and males differ in their subjective emotional reactions to facial expressions and in the emotional processes that modulate the detection of facial expressions.     

How a Spatial Arrangement of Secondary Structure Elements Is Dispersed in the Universe of Protein Folds

It has been known that topologically different proteins of the same class sometimes share the same spatial arrangement of secondary structure elements (SSEs). However, the frequency by which topologically different structures share the same spatial arrangement of SSEs is unclear. It is important to estimate this frequency because it provides both a deeper understanding of the geometry of protein folds and a valuable suggestion for predicting protein structures with novel folds. Here we clarified the frequency with which protein folds share the same SSE packing arrangement with other folds, the types of spatial arrangement of SSEs that are frequently observed across different folds, and the diversity of protein folds that share the same spatial arrangement of SSEs with a given fold, using a protein structure alignment program MICAN, which we have been developing. By performing comprehensive structural comparison of SCOP fold representatives, we found that approximately 80% of protein folds share the same spatial arrangement of SSEs with other folds. We also observed that many protein pairs that share the same spatial arrangement of SSEs belong to the different classes, often with an opposing N- to C-terminal direction of the polypeptide chain. The most frequently observed spatial arrangement of SSEs was the 2-layer α/β packing arrangement and it was dispersed among as many as 27% of SCOP fold representatives. These results suggest that the same spatial arrangements of SSEs are adopted by a wide variety of different folds and that the spatial arrangement of SSEs is highly robust against the N- to C-terminal direction of the polypeptide chain.     

Analysis of translesion replication across an abasic site by DNA polymerase IV of Escherichia coli

Unrepaired replication-blocking DNA lesions are bypassed by specialized DNA polymerases, members of the Y super-family. In Escherichia coli the major lesion bypass DNA polymerase is pol V, whereas the function of its homologue, pol IV, is not fully understood. In vivo analysis showed that pol V has a major role in bypass across an abasic site analog, with little or no involvement of pol IV. This can result from the inability of pol IV to bypass the abasic site, or from in vivo regulation of its activity. In vitro analysis revealed that purified pol IV, in the presence of the beta subunit DNA sliding clamp, and the gamma complex clamp loader, bypassed a synthetic abasic site with very high efficiency, reaching 73% in 2 min. Bypass was observed also in the absence of the processivity proteins, albeit at a 10- to 20-fold lower rate. DNA sequence analysis revealed that pol IV skips over the abasic site, producing primarily small deletions. The RecA protein inhibited bypass by pol IV, but this inhibition was alleviated by single-strand binding protein (SSB). The fact that the in vitro bypass ability of pol IV is not manifested under in vivo conditions suggests the presence of a regulatory factor, which might be involved in controlling the access of the bypass polymerases to the damaged site in DNA.     

Oncogenic Ras abrogates MEK SUMOylation that suppresses the ERK pathway and cell transformation

The ERK (extracellular signal-regulated kinase) MAPK (mitogen-activated protein kinase) cascade (Raf-MEK-ERK) mediates mitogenic signalling, and is frequently hyperactivated by Ras oncogenes in human cancer. The entire range of activities of multifunctional Ras in carcinogenesis remains elusive. Here we report that the ERK pathway is downregulated by MEK (MAPK-ERK kinase) SUMOylation, which is inhibited by oncogenic Ras. MEK SUMOylation blocked ERK activation by disrupting the specific docking interaction between MEK and ERK. Expression of un-SUMOylatable MEK enhanced ERK activation, cell differentiation, proliferation and malignant transformation by oncogenic ErbB2 or Raf, but not by active Ras. Interestingly, MEK SUMOylation was abrogated in cancer cells harbouring Ras mutations. Oncogenic Ras inhibits MEK SUMOylation by impairing the function of the MEKK1 MAPKKK as a SUMO-E3 ligase specific for MEK. Furthermore, forced enhancement of MEK SUMOylation suppressed Ras-induced cell transformation. Thus, oncogenic Ras efficiently activates the ERK pathway both by activating Raf and by inhibiting MEK SUMOylation, thereby inducing carcinogenesis.