Biology subjects

Zhai, D.

Publications and source records attributed to Zhai, D..

5 recordsLinked to original sources

bioRxiv2026

The nanoscale mobility of calcium channels is driven by readily releasable synaptic vesicles to support precise neurotransmission in live C. elegans

Precise neurotransmission requires voltage-gated calcium channels (VGCCs) to be tightly coupled with synaptic vesicles (SVs) at active zones (AZs). As VGCCs are mobile in the fluid presynaptic membrane, it remained unclear how they spatiotemporally align with SVs for reliable synaptic release. Using super-resolution imaging and single-molecule tracking in C. elegans, we report that two diffusive behaviors of N-type VGCCs at AZs are governed by primed SVs via distinct mechanisms. VGCCs diffuse slowly in multiple nanodomains ([~]100 nm) that spatially correlate with UNC-10/RIM, and the channels mobility and nanodomain numbers are coupled to SNAREs assembly and SV priming levels via RAB-3/UNC-10/UNC-13L tripartite complexes. Outside nanodomains, a faster mobility of VGCCs and their AZ distribution scale with UNC-13S-mediated priming under an antagonistic regulation by UNC-10 and TOM-1/Tomosyn. These findings reveal unexpected mechanisms whereby pools of readily releasable SVs actively control the nanoscale mobility and nanodomain organization of VGCCs to support precise neurotransmission.

neuroscience↗

bioRxiv2022

New high-resolution maps show that rubber causes significant deforestation

Understanding the impacts of cash crop expansion on natural forest is of fundamental importance. However, for most crops there are no remotely-sensed global maps1, and global deforestation impacts are estimated using models and extrapolations. Natural rubber is an example of a major commodity for which deforestation impacts have been highly uncertain, with estimates differing more than five-fold1-4. Here we harnessed earth observation satellite data and cloud computing5 to produce the first high-resolution maps of rubber and associated deforestation covering all Southeast Asia. Our maps indicate that rubber-related forest loss has been significantly underestimated in policy, by the public and in recent reports6-8. Our direct remotely-sensed observations show that deforestation for rubber is two to threefold higher than suggested by figures currently widely used for setting policy4. With over 3.76 million hectares of forest loss for rubber since 1993 (2.77 [2.5-3 95% CI] million hectares since 2000), and over 1 million hectares of rubber plantations established in Key Biodiversity Areas, the impacts of rubber on biodiversity and ecosystem services in Southeast Asia are extensive. Thus, rubber deserves more attention in domestic policy, within trade agreements and in incoming due diligence regulations.

ecology↗

bioRxiv2022

FoxP3-mediated blockage of ryanodine receptor 2 is the molecular basis for the contact-based suppression by regulatory T cells

The suppression mechanism of regulatory T cells is an intensely investigated topic. As our focus has shifted towards a model centered on indirect inhibition of dendritic cells, a universally applicable effector mechanism controlled by FoxP3 expression has not been found. Here, we report that FoxP3 blocks the transcription of ER Ca2+-release channel ryanodine receptor 2. Reduced RyR2 shuts down basal Ca2+ oscillation in Tregs, which reduces m-Calpain activities that is needed for T cells to disengage from DCs, suggesting a persistent blockage of DC antigen presentation. RyR2 deficiency renders the CD4+ T cell pool to become immune suppressive, and behave in the same manner as FoxP3+ Tregs in viral infection, asthma, hypersensitivity, colitis and tumor development. In the absence of FoxP3, RyR2-deficient CD4+ T cells rescue the systemic autoimmunity associated with Scurfy mice. Therefore, FoxP3-mediated Ca2+ signaling inhibition may be a central effector mechanism of Treg immune suppression. One Sentence SummaryCalcium channel RyR2 dictates Treg adhesion-based suppression

immunology↗

bioRxiv2021

Before trilobite legs: Pygmaclypeatus daziensis reconsidered and the ancestral appendicular organization of Cambrian artiopods

The Cambrian Stage 3 Chengjiang biota in South China is one of the most influential Konservat-Lagerstatten worldwide thanks to the fossilization of diverse non-biomineralizing organisms through pyritization. Despite their contributions to understanding the evolution of early animals, several Chengjiang species remain poorly known due to their scarcity and/or incomplete preservation. Here, we use micro-computed tomography to reveal in detail the ventral appendage organization of the enigmatic non-trilobite artiopod Pygmaclypeatus daziensis - one of the rarest euarthropods in Chengjiang - and explore its functional ecology and broader evolutionary significance. Pygmaclypeatus daziensis possesses a set of uniramous antennae and 14 pairs of post-antennal biramous appendages, the latter of which show an unexpectedly high degree of heteronomy based on the localized differentiation of the protopodite, endopodite and exopodite along the antero-posterior body axis. The small body size (less than 2 cm), presence of delicate spinose endites, and well-developed exopodites with multiple paddle-shaped lamellae on the appendages of P. daziensis indicate a nekto-benthic mode of life, and a scavenging/detritus feeding strategy. Pygmaclypeatus daziensis shows that appendage heteronomy is phylogenetically widespread within Artiopoda - the megadiverse clade that includes trilobites and their relatives with non-biomineralizing exoskeletons - and suggests that a single exopodite lobe with paddle-like lamellae is ancestral for this clade. O_FIG O_LINKSMALLFIG WIDTH=200 HEIGHT=155 SRC="FIGDIR/small/456779v1_ufig1.gif" ALT="Figure 1"> View larger version (111K): org.highwire.dtl.DTLVardef@b4ddaaorg.highwire.dtl.DTLVardef@44f686org.highwire.dtl.DTLVardef@1950095org.highwire.dtl.DTLVardef@1596739_HPS_FORMAT_FIGEXP M_FIG C_FIG Cover image: Morphological reconstruction of the non-trilobite artiopod Pygmaclypeatus daziensis from the early Cambrian (Stage 3) Chengjiang biota in south China. Artwork by Holly Sullivan (https://www.sulscientific.com/).

paleontology↗

bioRxiv2018

Knockdown of DGKZ induces apoptosis andG2/M phase arrest in human acute myeloid leukemia HL-60 cells

Diacylglycerol kinase zeta (DGKZ) is associated with the pathogenesis of a variety of malignant diseases, but its biological function on acute myeloid leukemia (AML) has not been explored. This study was aimed to analyze apoptosis induced by Knockdown of DGKZ and its mechanism in human acute myeloid leukemia HL-60 cells.In the present study qRT-PCR was used to detect the expression of DGKZ in HL-60, THP-1, K562, H9, Jurkat and CD34 cell lines. DGKZ-shRNA lentiviral vector was established and used to infect acute myeloid leukemia HL-60 cells. Cell Counting Kit-8 (CCK-8) assay was used to determine the viability of HL-60 cells DGKZ knocked down. Apoptosis and cell cycle phase of HL-60 cells after DGKZ knockdown were evaluated by flow cytometry. Western blot analysis was performed to investigated the protein expression related to apoptosis and cell cycle. Results showed DGKZ expression were stable and higher in Jurkat, HL-60, THP-1,K562 leukemia cells than those of H9 and CD34 cells. Compared with cells of the shCtrl group, DGKZ was markedly knocked down in cells which were transfected with lentivirus encoding shRNA of DGKZ in HL-60 cells. DGKZ knockdown significantly inhibited the proliferation and induced cycle arrest at the G2/M phase in HL-60 cells. Western blot results indicated the expressions of caspase-3, caspase-8, and survivin markedly increased in HL-60 cells after knockdown of DGKZ. The results suggest Knockdown of DGKZ can inhibit proliferation of acute myeloid leukemia HL-60 cell caused cell cycle arrest at the G2/M phase through caspases pathway.

cancer biology↗