RESUMEN
ASAP1 and its paralog ASAP2 belong to a PI4,5P2-dependent Arf GTPase-activating protein (Arf-GAP) family capable of modulating membrane and cytoskeletal dynamics. ASAPs regulate cell adhesive structures such as invadosomes and focal adhesions during cell attachment and migration. Malfunctioning of ASAP1 has been implicated in the malignant phenotypes of various cancers. Here, we discovered that the SH3 domain of ASAP1 or ASAP2 specifically binds to a 12-residue, positively charged peptide fragment from the 440 kDa giant ankyrin-B, a neuronal axon specific scaffold protein. The high-resolution structure of the ASAP1-SH3 domain in complex with the gAnkB peptide revealed a non-canonical SH3-ligand binding mode with high affinity and specificity. Structural analysis of the complex readily uncovered a consensus ASAP1-SH3 binding motif, which allowed the discovery of a number of previously unknown binding partners of ASAP1-SH3 including Clasp1/Clasp2, ALS2, ß-Pix, DAPK3, PHIP, and Limk1. Fittingly, these newly identified ASAP1 binding partners are primarily key modulators of the cytoskeletons. Finally, we designed a cell-penetrating, highly potent ASAP1 SH3 domain binding peptide with a Kd â¼7 nM as a tool for studying the roles of ASAPs in different cellular processes.
RESUMEN
The firmness of the flesh fruit is a very important feature in the eating process. Peach fruit is very hard during development, but its firmness slightly decreases in the later stages of development. While there has been extensive research on changes in cell wall polysaccharides during fruit ripening, little is known about the changes that occur during growth and development. In this study, we investigated the modifications in cell wall components throughout the development and ripening of peach fruit, as well as its impact on firmness. Our findings revealed a significant positive correlation between fruit firmness and cellulose content at development stage. However, the correlation was lost during the softening process, suggesting that cellulose might be responsible for the fruit firmness during development. Members of the chitinase-like protein (CTL) group are of interest because of their possible role in plant cell wall biosynthesis. Here, two CTL homologous genes, PpCTL1 and PpCTL2, were identified in peach. Spatial and temporal expression patterns of PpCTLs revealed that PpCTL1 exhibited high expression abundance in the fruit and followed a similar trend to cellulose during fruit growth. Furthermore, silencing PpCTL1 expression resulted in reduced cellulose content at 5 DAI (days after injection), this change that would have a negative effect on fruit firmness. Our results indicate that PpCTL1 plays an important role in cellulose biosynthesis and the maintenance of peach firmness during development.
RESUMEN
MEMS-based LiDAR with a low cost and small volume is a promising solution for 3D measurement. In this paper, a reconfigurable angular resolution design method is proposed in a separate-axis Lissajous scanning MEMS LiDAR system. This design method reveals the influence factors on the angular resolution, including the characteristics of the MEMS mirrors, the laser duty cycle and pulse width, the processing time of the echo signal, the control precision of the MEMS mirror, and the laser divergence angle. A simulation was carried out to show which conditions are required to obtain different angular resolutions. The experimental results of the 0.2° × 0.62° and 0.2° × 0.15° (horizontal × vertical) angular resolutions demonstrate the feasibility of the design method to realize a reconfigurable angular resolution in a separate-axis Lissajous scanning MEMS LiDAR system by employing MEMS mirrors with different characteristics. This study provides a reasonable potential to obtain a high and flexible angular resolution for MEMS LiDAR.
RESUMEN
MEMS-based LiDAR (micro-electro-mechanical system based light detection and ranging), with a low cost and small volume, becomes a promising solution for the two-dimensional (2D) and three-dimensional (3D) optical imaging. A semi-coaxial MEMS LiDAR design, based on a synchronous MEMS mirror pair, was proposed in our early study. In this paper, we specifically reveal the synchronization method of the comb-actuated MEMS mirror pair, including the frequency, amplitude, and phase synchronization. The frequency sweeping and phase adjustment are simultaneously implemented to accelerate the MEMS mirror synchronization process. The experiment is set up and the entire synchronization process is completed within 5 s. Eventually, a one-beam MEMS LiDAR system with the synchronous MEMS mirror pair is set up and a LiDAR with a field of view (FOV) of 60°, angular resolution of 0.2°, and frame rate of 360 Hz is obtained. The experimental results verify the feasibility of the MEMS mirror synchronization method and show a promising potential application prospect for the MEMS LiDAR system.
RESUMEN
Sepsis is a severe, life-threatening condition primarily caused by the cellular response to infection. Sepsis leads to increased tissue damage and mortality in patients in the intensive care unit. L-Lysine is an essential amino acid required for protein biosynthesis and is abundant in lamb, pork, eggs, red meat, fish oil, cheese, beans, peas, and soy. Male albino rats were divided into sham, control, 10-mg/kg bwt L-lysine, and 20-mg/kg bwt L-lysine groups. At the end of treatment, we determined the levels of oxidative and inflammatory markers, myeloperoxidase (MPO) and catalase activities, total cell count, the wet/dry ratio of lung tissue, and total protein content. Furthermore, the effect of L-lysine on the cellular architecture of lung tissue was evaluated. L-Lysine significantly reduced the magnitude of lipid peroxidation; total protein content; wet/dry ratio of lung tissue; tumor necrosis factor-alpha, interleukin-8, and macrophage inhibitory factor levels; MPO activity; and total cell, neutrophil, and lymphocyte counts, and it increased the reduced glutathione levels and the glutathione peroxidase, superoxide dismutase, and catalase activities. A normal cellular architecture was noted in rats in the sham group, whereas proinflammatory changes, such as edema and neutrophilic infiltration, were detected in rats in the control group. L-lysine significantly ameliorated these proinflammatory changes. Thus, L-lysine has the potential for the treatment of sepsis-induced CLI.