V1 Alyssia 声望 1 生理学与生物物理学 2021-09-16 21:41:15 上传
Solution structure of the rat P2X4 receptor head domain involved in inhibitory metal binding
Abstract The P2X receptor is an ATP-gated cation channel expressed on the plasma membrane. The head domain (Gln111–Val167 in the rat P2X4 receptor) regulates ATP-induced cation influx. In this study, we prepared a head domain with three disulfide bonds, such as the intact rat P2X4 receptor contains. NMR analysis showed that the head domain possessed the same fold as in the zebrafish P2X4 receptor previously determined by crystallography. Furthermore, the inhibitory, divalent, metal ion binding sites were determined by NMR techniques. These findings will be useful for the design of specific inhibitors for the P2X receptor family.
V1 北邮老土 声望 1 生物工程 2021-09-15 20:41:32 上传
Identification and evolution of the orphan genes in the domestic silkworm, Bombyx mori
Abstract Orphan genes (OGs) which have no recognizable homology to any sequences in other species could contribute to the species specific adaptations. In this study, we identified 738 OGs in the silkworm genome. About 31% of the silkworm OGs is derived from transposable elements, and 5.1% of the silkworm OGs emerged from gene duplication followed by divergence of paralogs. Five de novo silkworm OGs originated from non-coding regions. Microarray data suggested that most of the silkworm OGs were expressed in limited tissues. RNA interference experiments suggested that five de novo OGs are not essential to the silkworm, implying that they may contribute to genetic redundancy or species-specific adaptation. Our results provide some new insights into the evolutionary significance of the silkworm OGs.
V3 叶与秋 声望 59 生物技术 2021-09-15 07:12:33 上传
Reptin physically interacts with p65 and represses NF-κB activation
Abstract Reptin and Pontin belong to the AAA+ ATPase family of DNA helicases. Both proteins are present in several chromatin-remodeling machineries and are involved in transcriptional regulation, DNA repair, and telomerase activity, but they also function independently from each other. Here we report the identification of p65 as an interacting partner of Reptin. Using reporter gene assays, we show Reptin inhibits NF-κB transactivation after TNFα stimulation. Reptin is mainly localized in the cytoplasm and impedes NF-κB activation by inhibiting IκB-α degradation and restraining p65 nuclear translocation. These results reveal a novel mechanism for the control of NF-κB pathway by cytoplasmic Reptin.
V2 无戒 声望 8 生态与进化生物学系 2021-09-14 13:16:05 上传
Communication between circadian clusters: The key to a plastic network
Abstract Drosophila melanogaster is a model organism that has been instrumental in understanding the circadian clock at different levels. A range of studies on the anatomical and neurochemical properties of clock neurons in the fly led to a model of interacting neural circuits that control circadian behavior. Here we focus on recent research on the dynamics of the multiple communication pathways between clock neurons, and, particularly, on how the circadian timekeeping system responds to changes in environmental conditions. It is increasingly clear that the fly clock employs multiple signalling cues, such as neuropeptides, fast neurotransmitters, and other signalling molecules, in the dynamic interplay between neuronal clusters. These neuronal groups seem to interact in a plastic fashion, e.g., rearranging their hierarchy in response to changing environmental conditions. A picture is emerging supporting that these dynamic mechanisms are in place to provide an optimal balance between flexibility and an extraordinary accuracy.
V2 弓谷所長 声望 7 生物信息学 2021-09-13 23:07:17 上传
Unusual effects of crowders on heme retention in myoglobin
Abstract Myoglobin (Mb) undergoes pronounced heme loss under denaturing conditions wherein the proximal histidine gets protonated. Our data show that macromolecular crowding agents (both synthetic and protein based) can appreciably influence the extent of heme retention in Mb. Interestingly, glucose and sucrose, the monomeric constituents of dextran and ficoll-based crowders were much more effective in preventing heme dissociation of Mb, albeit, at much higher concentrations. The protein crowders BSA and lysozyme show very interesting results with BSA bringing about the maximum heme retention amongst all the crowding agents used while lysozyme induced heme dissociation even in the native state of Mb. The stark difference that these protein crowders exhibit when interacting with the heme protein is a testament to the varied interaction potentials that a test protein might be exposed to in the physiological (crowded) milieu.
V1 高连仁 声望 1 动植物检疫 2021-09-13 10:43:53 上传
Dissecting the functional roles of the conserved NXXE and HXE motifs of the ADP-dependent glucokinase from Thermococcus litoralis
Abstract The activity of the ADP-dependent glucokinase from Thermococcus litoralis (TlGK) relies on the highly conserved motifs NXXE (i.e. Asn-Xaa-Xaa-Glu) and HXE (i.e. His-Xaa-Glu). Site-directed mutagenesis of residues Glu279 (HXE) and Glu308 (NXXE) leads to enzymes with highly reduced catalytic rates. The replacement of Glu308 by Gln increased the KM for MgADP− and was activated by free Mg2+. On the other hand, HXE mutants did not affect the KM for MgADP−, were still inhibited by free Mg2+, and caused a large increase on KM for glucose and an 87-fold weaker binding of glucose onto the non-hydrolysable TlGK·AMP–AlF3 complex. Our findings put forward the fundamental role of the HXE motif in glucose binding during ternary complex formation.
V1 丁磊宇 声望 1 生物信息技术 2021-09-13 03:03:27 上传
Specific mutations in mammalian P4-ATPase ATP8A2 catalytic subunit entail differential glycosylation of the accessory CDC50A subunit
Abstract P4-ATPases, or flippases, translocate phospholipids between the two leaflets of eukaryotic biological membranes. They are essential to the physiologically crucial phospholipid asymmetry and involved in severe diseases, but their molecular structure and mechanism are still unresolved. Here, we show that in an extensive mutational alanine screening of the mammalian flippase ATP8A2 catalytic subunit, five mutations stand out by leading to reduced glycosylation of the accessory subunit CDC50A. These mutations may disturb the interaction between the subunits.
V4 我很忙 声望 26 2021-09-13 01:23:11 上传
Functionality of Class A and Class B J-protein co-chaperones with Hsp70
Abstract At their C-termini, cytosolic Hsp70s have an EEVD tetrapeptide that interacts with J-protein co-chaperones of the B, but not A, class. This interaction is required for partnering with yeast B-type J-proteins in protein folding. Here we report conservation of this feature. Human B-type J-proteins also have a stringent EEVD requirement. Human A-type J-proteins function less well than their yeast orthologs with Hsp70ΔEEVD. Changes in the zinc binding domain, a domain absent in B-type J-proteins, overcomes this partial EEVD dependence. Our results suggest that the structurally similar A- and B-class J-proteins of the cytosol have evolved conserved, yet distinct, features that enhance specialized functionality of Hsp70 machinery.
V2 弗拉明哥 声望 11 生物科学 2021-09-12 23:17:08 上传
Insights into the behavioral difference of water in the presence of GM1
Abstract Studies on the structure and dynamics of interfacial water, emphasizing on the properties of water near the surface of biomolecules, are well reported, but there is a lack of evidence on the behavior of water near a comparatively rough surface containing molecules with a bulky head group like GM1. In this report we comparatively analyze the structure and dynamics of water as a function of distance from the lipid head group in GM1 containing lipid bilayers, with the lipid bilayers where GM1 is not present. This approach effectively demonstrates the behavioral difference and hence delayed convergence from bound water to bulk water in the presence of GM1 compared to a relatively smooth surface.
V2 心海涤尘 声望 12 动植物检疫 2021-09-12 19:34:12 上传
Phosphorylation of Serine422 increases the stability and transactivation activities of human Osterix
Abstract Osterix (Osx) is an essential regulator for osteoblast differentiation and bone formation. Although phosphorylation has been reported to be involved in the regulation of Osx activity, the precise underlying mechanisms remain to be elucidated. Here we identified S422 as a novel phosphorylation site of Osx and demonstrated that GSK-3β interacted and co-localized with Osx. GSK-3β increased the stability and transactivation activity of Osx through phosphorylation of the newly identified site. These findings expanded our understanding of the mechanisms of posttranslational regulation of Osx and the role of GSK-3β in the control of Osx transactivation activity.

生物化学是指用化学的方法和理论研究生命的化学分支学科。其任务主要是了解生物的化学组成、结构及生命过程中各种化学变化。从早期对生物总体组成的研究,进展到对各种组织和细胞成分的精确分析。目前正在运用诸如光谱分析、同位素标记、X射线衍射、电子显微镜以及其他物理学、化学技术,对重要的生物大分子(如蛋白质、核酸等)进行分析,以此说明这些生物大分子的多种多样的功能与它们特定的结构关系。