197 research outputs found
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PhOBF1, a petunia ocs element binding factor, plays an important role in antiviral RNA silencing.
Virus-induced gene silencing (VIGS) is a common reverse genetics strategy for characterizing the function of genes in plants. The detailed mechanism governing RNA silencing efficiency triggered by viruses is largely unclear. Here, we reveal that a petunia (Petunia hybrida) ocs element binding factor, PhOBF1, one of the basic leucine zipper (bZIP) transcription factors, was up-regulated by Tobacco rattle virus (TRV) infection. Simultaneous silencing of PhOBF1 and a reporter gene, phytoene desaturase (PDS) or chalcone synthase (CHS), by TRV-based VIGS led to a failure of the development of leaf photobleaching or the white-corollas phenotype. PhOBF1 silencing caused down-regulation of RNA silencing-related genes, including RNA-dependent RNA polymerases (RDRs), Dicer-like RNase III enzymes (DCLs), and Argonautes (AGOs). After inoculation with the TRV-PhPDS, PhOBF1-RNAi lines exhibited a substantially impaired PDS silencing efficiency, whereas overexpression of PhOBF1 resulted in a recovery of the silencing phenotype (photobleaching) in systemic leaves. A compromised resistance to TRV and Tobacco mosaic virus was found in PhOBF1-RNAi lines, while PhOBF1-overexpressing lines displayed an enhanced resistance to their infections. Compared with wild-type plants, PhOBF1-silenced plants accumulated lower levels of free salicylic acid (SA), salicylic acid glucoside, and phenylalanine, contrarily to higher levels of those in plants overexpressing PhOBF1. Furthermore, transcripts of a number of genes associated with the shikimate and phenylpropanoid pathways were decreased or increased in PhOBF1-RNAi or PhOBF1-overexpressing lines, respectively. Taken together, the data suggest that PhOBF1 regulates TRV-induced RNA silencing efficiency through modulation of RDRs, DCLs, and AGOs mediated by the SA biosynthesis pathway
A petunia ethylene-responsive element binding factor, PhERF2, plays an important role in antiviral RNA silencing.
Virus-induced RNA silencing is involved in plant antiviral defense and requires key enzyme components, including RNA-dependent RNA polymerases (RDRs), Dicer-like RNase III enzymes (DCLs), and Argonaute proteins (AGOs). However, the transcriptional regulation of these critical components is largely unknown. In petunia (Petunia hybrida), an ethylene-responsive element binding factor, PhERF2, is induced by Tobacco rattle virus (TRV) infection. Inclusion of a PhERF2 fragment in a TRV silencing construct containing reporter fragments of phytoene desaturase (PDS) or chalcone synthase (CHS) substantially impaired silencing efficiency of both the PDS and CHS reporters. Silencing was also impaired in PhERF2- RNAi lines, where TRV-PhPDS infection did not show the expected silencing phenotype (photobleaching). In contrast, photobleaching in response to infiltration with the TRV-PhPDS construct was enhanced in plants overexpressing PhERF2 Transcript abundance of the RNA silencing-related genes RDR2, RDR6, DCL2, and AGO2 was lower in PhERF2-silenced plants but higher in PhERF2-overexpressing plants. Moreover, PhERF2-silenced lines showed higher susceptibility to Cucumber mosaic virus (CMV) than wild-type (WT) plants, while plants overexpressing PhERF2 exhibited increased resistance. Interestingly, growth and development of PhERF2-RNAi lines were substantially slower, whereas the overexpressing lines were more vigorous than the controls. Taken together, our results indicate that PhERF2 functions as a positive regulator in antiviral RNA silencing
Color-NeuS: Reconstructing Neural Implicit Surfaces with Color
The reconstruction of object surfaces from multi-view images or monocular
video is a fundamental issue in computer vision. However, much of the recent
research concentrates on reconstructing geometry through implicit or explicit
methods. In this paper, we shift our focus towards reconstructing mesh in
conjunction with color. We remove the view-dependent color from neural volume
rendering while retaining volume rendering performance through a relighting
network. Mesh is extracted from the signed distance function (SDF) network for
the surface, and color for each surface vertex is drawn from the global color
network. To evaluate our approach, we conceived a in hand object scanning task
featuring numerous occlusions and dramatic shifts in lighting conditions. We've
gathered several videos for this task, and the results surpass those of any
existing methods capable of reconstructing mesh alongside color. Additionally,
our method's performance was assessed using public datasets, including DTU,
BlendedMVS, and OmniObject3D. The results indicated that our method performs
well across all these datasets. Project page:
https://colmar-zlicheng.github.io/color_neus
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DNA damage-induced activation of ATM promotes β-TRCP-mediated Mdm2 ubiquitination and destruction
The Mdm2 oncoprotein promotes p53 ubiquitination and destruction. Yet, exact molecular mechanisms of Mdm2 destruction itself, under DNA damaging conditions, remain unclear. Recently, we identified SCFβ-TRCP as a novel E3 ligase that targets Mdm2 for ubiquitination and destruction in a Casein Kinase Iδ (CKIδ)-dependent manner. However, it remains elusive how the β-TRCP/CKIδ/Mdm2 signaling axis is regulated by DNA damage signals to govern p53 activity. Consistent with previous studies, we found that inactivation of the Ataxia Telangiectasia Mutated (ATM) kinase, in turn, impaired DNA damage-induced Mdm2 destruction. Although phosphorylation of Mdm2 at Ser395 (an ATM phosphorylation site) facilitated Mdm2 interaction with β-TRCP, Ser395A-Mdm2 was degraded non-distinguishably from WT-Mdm2 by SCFβ-TRCP upon DNA damaging treatments. This indicates that in addition to phosphorylating Mdm2 at Ser395, ATM may govern Mdm2 stability through other unknown mechanisms. We further demonstrated that DNA damage-induced activation of ATM directly phosphorylated CKIδ at two well-conserved S/TQ sites, which promotes CKIδ nuclear localization to increase CKIδ-mediated phosphorylation of Mdm2, thereby facilitating subsequent Mdm2 ubiquitination by SCFβ-TRCP. Our studies provide a molecular mechanism of how ATM could govern DNA damage-induced destruction of Mdm2 in part by phosphorylating both Mdm2 and CKIδ to modulate SCFβ-TRCP–mediated Mdm2 ubiquitination. Given the pivotal role of Mdm2 in the negative regulation of p53, this work will also provide a rationale for developing CKIδ or ATM agonists as anti-cancer agents
Time scales of epidemic spread and risk perception on adaptive networks
Incorporating dynamic contact networks and delayed awareness into a contagion
model with memory, we study the spreading patterns of infectious diseases in
connected populations. It is found that the spread of an infectious disease is
not only related to the past exposures of an individual to the infected but
also to the time scales of risk perception reflected in the social network
adaptation. The epidemic threshold is found to decrease with the rise
of the time scale parameter s and the memory length T, they satisfy the
equation .
Both the lifetime of the epidemic and the topological property of the evolved
network are considered. The standard deviation of the degree
distribution increases with the rise of the absorbing time , a power-law
relation is found
POEM: Reconstructing Hand in a Point Embedded Multi-view Stereo
Enable neural networks to capture 3D geometrical-aware features is essential
in multi-view based vision tasks. Previous methods usually encode the 3D
information of multi-view stereo into the 2D features. In contrast, we present
a novel method, named POEM, that directly operates on the 3D POints Embedded in
the Multi-view stereo for reconstructing hand mesh in it. Point is a natural
form of 3D information and an ideal medium for fusing features across views, as
it has different projections on different views. Our method is thus in light of
a simple yet effective idea, that a complex 3D hand mesh can be represented by
a set of 3D points that 1) are embedded in the multi-view stereo, 2) carry
features from the multi-view images, and 3) encircle the hand. To leverage the
power of points, we design two operations: point-based feature fusion and
cross-set point attention mechanism. Evaluation on three challenging multi-view
datasets shows that POEM outperforms the state-of-the-art in hand mesh
reconstruction. Code and models are available for research at
https://github.com/lixiny/POEM.Comment: Accepted by CVPR 202
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SCFβ-TRCP targets MTSS1 for ubiquitination-mediated destruction to regulate cancer cell proliferation and migration
Metastasis suppressor 1 (MTSS1) is an important tumor suppressor protein, and loss of MTSS1 expression has been observed in several types of human cancers. Importantly, decreased MTSS1 expression is associated with more aggressive forms of breast and prostate cancers, and with poor survival rate. Currently, it remains unclear how MTSS1 is regulated in cancer cells, and whether reduced MTSS1 expression contributes to elevated cancer cell proliferation and migration. Here we report that the SCFβ-TRCP regulates MTSS1 protein stability by targeting it for ubiquitination and subsequent destruction via the 26S proteasome. Notably, depletion of either Cullin 1 or β-TRCP1 led to increased levels of MTSS1. We further demonstrated a crucial role for Ser322 in the DSGXXS degron of MTSS1 in governing SCFβ-TRCP-mediated MTSS1 degradation. Mechanistically, we defined that Casein Kinase Iδ (CKIδ) phosphorylates Ser322 to trigger MTSS1's interaction with β-TRCP for subsequent ubiquitination and degradation. Importantly, introducing wild-type MTSS1 or a non-degradable MTSS1 (S322A) into breast or prostate cancer cells with low MTSS1 expression significantly inhibited cellular proliferation and migration. Moreover, S322A-MTSS1 exhibited stronger effects in inhibiting cell proliferation and migration when compared to ectopic expression of wild-type MTSS1. Therefore, our study provides a novel molecular mechanism for the negative regulation of MTSS1 by β-TRCP in cancer cells. It further suggests that preventing MTSS1 degradation could be a possible novel strategy for clinical treatment of more aggressive breast and prostate cancers
CHORD: Category-level Hand-held Object Reconstruction via Shape Deformation
In daily life, humans utilize hands to manipulate objects. Modeling the shape
of objects that are manipulated by the hand is essential for AI to comprehend
daily tasks and to learn manipulation skills. However, previous approaches have
encountered difficulties in reconstructing the precise shapes of hand-held
objects, primarily owing to a deficiency in prior shape knowledge and
inadequate data for training. As illustrated, given a particular type of tool,
such as a mug, despite its infinite variations in shape and appearance, humans
have a limited number of 'effective' modes and poses for its manipulation. This
can be attributed to the fact that humans have mastered the shape prior of the
'mug' category, and can quickly establish the corresponding relations between
different mug instances and the prior, such as where the rim and handle are
located. In light of this, we propose a new method, CHORD, for Category-level
Hand-held Object Reconstruction via shape Deformation. CHORD deforms a
categorical shape prior for reconstructing the intra-class objects. To ensure
accurate reconstruction, we empower CHORD with three types of awareness:
appearance, shape, and interacting pose. In addition, we have constructed a new
dataset, COMIC, of category-level hand-object interaction. COMIC contains a
rich array of object instances, materials, hand interactions, and viewing
directions. Extensive evaluation shows that CHORD outperforms state-of-the-art
approaches in both quantitative and qualitative measures. Code, model, and
datasets are available at https://kailinli.github.io/CHORD.Comment: To be presented at ICCV 2023, Pari
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Crif1 Promotes Osteoporosis in Mice after Radiation
Abstract Radiation induces rapid bone loss and enhances bone resorption and RANKL expression. RANKL provides the crucial signal to induce osteoclast differentiation and plays an important role in bone resorption. However, the mechanisms of radiation-induced osteoporosis are not fully understood. Here, we show that Crif1 expression increases in bone marrow cells after radiation. Conditional Crif1 deletion in bone marrow cells causes decreases in RANKL expression and the RANKL/OPG ratio, and relieves bone loss after radiation in mice. We further demonstrated in vitro that Crif1 promotes RANKL secretion via the cAMP/PKA pathway. Moreover, protein-protein docking screening identified five compounds as Crif1 inhibitors; these compounds dramatically suppressed RANKL secretion and CREB phosphorylation when cells were exposed to forskolin. This study enriches current knowledge of the pathogenesis of osteoporosis and provides insights into potential therapeutic strategies for osteoporosis treatment
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