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Zhou, X.

Publications and source records attributed to Zhou, X..

At least 199 records · Page 11Linked to original sources

Decoding the Molecular Language of Proteins with Evola

Proteins, natures intricate molecular machines, are the products of billions of years of evolution and play fundamental roles in sustaining life. Yet, deciphering their molecular language--understanding how sequences and structures encode biological functions--remains a cornerstone challenge. Here, we introduce Evolla, an interactive protein-language model designed to transcend static classification by interpreting protein function through natural language queries. Trained on 546 million protein-text pairs and refined via Direct Preference Optimization, Evolla couples high-dimensional molecular representations with generative semantic decoding. Benchmarking establishes Evollas superiority over general large language models in functional inference, demonstrates zero-shot performance parity with the state-of-the-art supervised model, and exposes remote functional relationships invisible to conventional alignment. We validate Evolla through two distinct applications: identifying candidate eukaryotic signature proteins in Asgard archaea, with functional Vps4 homologs validated via yeast complementation; and interactively discovering a novel deep-sea polyethylene terephthalate (PET) hydrolase, PsPETase, confirmed to degrade plastic films. These results position Evolla not merely as a predictor, but as a generative engine capable of complex hypothesis formulation, shifting the paradigm from static annotation to interactive, actionable discovery. The Evolla online service is available at http://www.chat-protein.com/.

bioinformatics↗

Using green space virtual reality to prevent stress-induced working memory impairment

Exposure to green space is associated with both physical and mental health benefits, including the potential to buffer acute stress responses, positioning it as a promising non-pharmacological approach to protect cognitive functions against stress. However, urban residents often face significant barriers in accessing green spaces, which are not equitably distributed. Virtual Reality (VR) technology offers a potential solution by simulating green space that could be made accessible to a broader demographic. Here, we explored whether VR-stimulated green space could dampen biological stress responses (i.e., heart rate and cortical response) and prevent stress-induced working memory (WM) impairment. Healthy young participants underwent acute stress induction followed by 15 minutes of VR-based green space (N=36) or control empty space (N=30) intervention. Although we observed the expected stress-induced increase in heart rates and elevated cortisol levels under stress, VR green space exposure failed to temper cortisol responses compared to the control VR space. Further, VR green space exposure did not bring benefits to protect working memory performance under stress across three WM tasks. Applying a Bayesian analysis approach throughout enabled us to find substantial evidence for the absence of an effect of VR-based green space exposure on biological markers of acute stress responses and working memory performance. Our findings suggest that VR-generated green space may not effectively replicate the stress-buffering effects of actual green space exposure. We discussed the implications of our findings regarding the potential and limitations of using VR or green space exposure to buffer stress responses.

neuroscience↗

Bipolar and schizophrenia risk gene AKAP11 encodes an autophagy receptor coupling the regulation of PKA kinase network homeostasis to synaptic transmission

Human genomic studies have identified protein-truncating variants in AKAP11 associated with both bipolar disorder (BD) and schizophrenia (SCZ), implicating a shared disease mechanism driven by loss-of-function. AKAP11, a protein kinase A (PKA) adaptor, plays a key role in degrading the PKA-RI complex through selective autophagy. However, the neuronal functions of AKAP11 and the impact of its loss-of-function remains largely uncharacterized. Through multi-omics approaches, cell biology, and electrophysiology analysis in mouse models and human induced neurons, we delineated a central role of AKAP11 in coupling PKA kinase network regulation to synaptic transmission. Loss of AKAP11 distorted compartment-specific PKA and GSK3/{beta} activities and impaired cellular functions that significantly overlap with pathways associated with BD and SCZ. Moreover, we identified interactions between AKAP11, the PKA-RI adaptor SPHKAP, and the ER-resident autophagy-related proteins VAPA/B, which co-adapt and mediate PKA-RI complex degradation in neurons. Notably, AKAP11 deficiency impaired neurotransmission, providing key insights into the mechanism underlying AKAP11-associated psychiatric diseases.

neuroscience↗

Dissociable neurofunctional and molecular characterizations of reward and punishment sensitivity

While the hyper-and hypo-reward or punishment sensitivities (RS, PS) have received considerable attention as prominent transdiagnostic features of psychopathology, the lack of an overarching neurobiological characterization currently limits their early identifications and neuromodulations. Here we combined microarray data from the Allen Human Brain Atlas with a multimodal fMRI approach to uncover the neurobiological signatures of RS and PS in a discovery-replication design (N=655 participants). Both RS and PS were mapped separately in the brain, with the intrinsic functional connectome in the fronto-striatal network encoding reward responsiveness, while the fronto-insular system was particularly engaged in punishment sensitivity. This dissociable functional connectome patterns related to RS and PS were also specific in differentiating decisions driven by social or monetary reward and punishment motivations. Further imaging transcriptomic analyses revealed that functional connectome variations for RS and PS were associated with topography of specific gene sets enriched in ontological pathways, including synaptic transmission, dopaminergic metabolism, immune response and stress adaptation. On the neurotransmitter level, the serotonin neuromodulator was identified as a pivotal hub regulating the intrinsic functional connectome patterns of RS and PS, with this process critically dependent on its interactions with dopaminergic, opioid and GABAergic systems. Overall, these findings indicate dissociable neural connectome mapping of RS and PS and highlight their linkage with transcriptomic profiles, which may offer valuable insights into the treatment evaluation for symptomatology relevant to reward/punishment processing deficits.

neuroscience↗

A General Strategy to Endow Dyes with Genic Fluorescence for Wash-Free Imaging of Proteins in Living Cells

Fluorescent dyes are the main fluorophore for protein labeling and fluorescent imaging in living cells. However, due to the inevitable nonspecific binding of the dye to non-targets within the cell, background signals are generated, which severely affect the imaging quality. Here, we endow the dye with genic fluorescence by introducing a fluorescent proteins FRET pair, such that only the dye bound to the target protein emits fluorescence ({lambda}ex = FPs, {lambda}em = Dyes), while nonspecifically bound dye remains non-fluorescent. This significantly improves the signal-to-noise ratio (SNR) in wash-free imaging. This strategy is achieved by fusing the Halo-tag to fluorescent proteins (sfGFP, mCherry) that can generate FRET with Halo dyes O-Rho and Si-Rho. The FPs serve as the donor, and the FRET mechanism imparts genic fluorescence property to O-Rho and Si-Rho. Since the excitation wavelength of the donor ({lambda}ex = FPs) cannot excite the unspecifically dye fluorescence, background fluorescence interference is reduced. We further improved the SNR by increasing the FRET efficiency between the FPs and dyes. The system was used for four-color super-resolution imaging of target proteins and dynamic SIM tracking of mitochondria. In addition, the genic FRET fluorophore constructed with the ultra-stable mStayGold showed significant photobleaching resistance and can be used for long-term dynamic super-resolution imaging. Theoretically, by selecting appropriate FRET pairs, this method can improve the SNR of any fluorophore, providing a new labeling strategy for live-cell wash-free imaging.

biochemistry↗

A new class of penicillin-binding protein inhibitors to address drug-resistant Neisseria gonorrhoeae

{beta}-Lactams are the most widely used antibiotics for the treatment of bacterial infections because of their proven track record of safety and efficacy. However, susceptibility to {beta}-lactam antibiotics is continually eroded by resistance mechanisms. Emerging multidrug-resistant (MDR) Neisseria gonorrhoeae strains possessing altered penA alleles (encoding PBP2) pose a global health emergency as they threaten the utility of ceftriaxone, the last remaining outpatient antibiotic. Here we disclose a novel benzoxaborinine-based penicillin-binding protein inhibitor series (boro-PBPi) that is envisioned to address penA-mediated resistance while offering protection against evolution and expansion of {beta}-lactamases. Optimization of boro-PBPi led to the identification of compound 21 (VNRX-14079) that exhibits potent antibacterial activity against MDR N. gonorrhoeae achieved by high affinity binding to the PBP2 target. Boro-PBPi/PBP2 complex structures confirmed covalent interaction of the boron atom with Ser310 and the importance of the {beta}3-{beta}4 loop for improved affinity. 21 elicits bactericidal activity, a low frequency of resistance, a good safety profile, suitable pharmacokinetic properties, and in vivo efficacy in a murine infection model against ceftriaxone-resistant N. gonorrhoeae. 21 is a promising anti-gonorrhea agent poised for further advancement.

microbiology↗

Leveraging Drosophila Models to Explore AI-generated Synthetic Peptide's Potential in Boosting Honeybee Health and Resilience

The integration of artificial intelligence (AI) and machine learning (ML) in peptide design has revolutionized the development of antimicrobial peptides (AMPs), which are essential components of innate immunity. In this study, we identified a novel synthetic peptide, PAN4 (GAYTFKIRRK), through genetic screening of AI-generated candidates in Drosophila melanogaster. PAN4 demonstrated robust antimicrobial activity, stress tolerance, and antitumor effects, significantly enhancing survival rates following bacterial infections and improving locomotor behaviors without adversely affecting lifespan. Furthermore, PAN4 expression in intestinal stem cells completely suppressed RasV12-induced tumor progression, indicating its potential role in cancer prevention. The peptide also mitigated gut barrier dysfunction associated with sleep deprivation and reduced inflammation in a dextran sulfate sodium (DSS)-induced colitis model. Mechanistically, PAN4s antimicrobial activity was linked to its interaction with specific peptidoglycan recognition proteins (PGRPs), particularly PGRP-SC1a, while the Tak1-mediated immune signaling pathway was found to be non-essential for its efficacy. PAN4 showed promising effects on honeybee health, enhancing survival rates under bacterial stress. Furthermore, PAN4 expression demonstrated significant anti-tumor activity in the Drosophila gut tumor model. Our findings suggest that PAN4 serves as a versatile agent with significant implications for enhancing immune responses and combating diseases in honeybee populations, paving the way for future applications in agriculture and medicine.

genetics↗

Chicken shank color determined by Inhibition of dermal melanin (ID) is mediated by a structural variation regulating CDKN2A expression

It is well established that the color of a chickens shank is primarily determined by four genetic loci. Among these, the Inhibition of dermal melanin (ID) locus, which suppresses black pigmentation in the dermal layer of the shank, is the sole sex-linked mutation and its molecular mechanisms remained elusive. In this study, a resource family with segregating shank colors was constructed. A genome-wide association study utilizing FarmCPU software identified a top-associated SNP located on the Z chromosome. Subsequent linkage mapping further refined the candidate region, enabling the screening of the candidate structural variation. The candidate structural variation is associated with the yellow shank and characterized by a 143 bp deletion accompanied by a 2 bp insertion. Within the same Topologically Associating Domain, only the CDKN2A gene showed differential expression. Functional studies, including CRISPR/Cas9-edited cells, provided evidence that this mutation regulates CDKN2A transcription and is responsible for the ID shank color in chickens. The absence of melanocytes is likely due to their apoptosis. This study completes the puzzle of chicken shank color genetics and paves the way for the application of the ID mutation in the auto-sexing of chicks which is intensively needed in layer and broiler industries.

genetics↗

Oligomerization of PRMT1 Regulated RNA-Binding Protein Cascade Promotes Pancreatic Ductal Adenocarcinoma

PRMT1 is the predominant type I protein arginine methyltransferase responsible for generating monomethylarginine and asymmetric dimethylarginine (MMA and ADMA) in various protein substrates. It regulates numerous biological processes, including RNA metabolism, mRNA splicing, DNA damage repair, and chromatin dynamics. The crystal structure of rat PRMT1 has been previously reported as a homodimer; however, higher-order oligomeric species of human PRMT1 have been observed in vivo, and their structural basis remains elusive. In this study, we present the cryo-EM structure of human PRMT1 in its oligomeric form, revealing novel interfaces crucial for PRMT1 self-assembly and normal function. PRMT1 shows a strong preference for intrinsically disordered RGG/RG motifs, which are commonly found in RNA-binding proteins (RBPs), highlighting its critical role in regulating RNA metabolism. In vitro studies indicate that disrupting PRMT1 oligomerization impairs its binding affinity for RGG motif substrates, thereby reducing arginine methylation levels on these substrates. This finding emphasizes the essential role of the oligomeric state of PRMT1 in its function with RGG motif-containing RBPs. In vivo, the loss of PRMT1 oligomerization leads to decreased global ADMA levels in pancreatic ductal adenocarcinoma (PDAC) cells and inhibits PDAC tumor growth. Collectively, we propose that PRMT1 oligomerization, rather than mere dimerization, is sufficient for PRMT1-driven PDAC tumor growth, offering novel insights into the potential therapeutic targeting of PRMT1 oligomeric forms in PDAC. Graphical abstract O_FIG O_LINKSMALLFIG WIDTH=200 HEIGHT=177 SRC="FIGDIR/small/627716v1_ufig1.gif" ALT="Figure 1"> View larger version (40K): org.highwire.dtl.DTLVardef@1ed6232org.highwire.dtl.DTLVardef@1c9e688org.highwire.dtl.DTLVardef@3e2c43org.highwire.dtl.DTLVardef@1cbf33e_HPS_FORMAT_FIGEXP M_FIG C_FIG

biochemistry↗

Genome-wide mapping of EBV-induced genomic variationsidentifies the role of MUC19 in EBV latency

Epstein-Barr virus (EBV) infects over 95% of the worlds population and is tightly associated with multiple human malignant diseases. As the first discovered human oncovirus, EBV is known to induce genomic instability by promoting various types of genomic modifications in host chromosomes. However, the mechanisms through which EBV interacts with the host genome and regulates cellular gene expression in genomic modifications are not yet fully elucidated. In this study, we conducted primary EBV infection in B cells and performed the analyses of copy number variants using whole genome sequencing. After comparing to other distinct B cells with varying EBV infection backgrounds, we identified susceptible regions and unveiled critical host factors induced by EBV infection on chromosomes. Combined with the genome-wide transcriptomic analyses, we found that the mucin gene MUC19 is distinctively activated by EBV infection and MUC19 promotes oncogenesis through the activation of mTOR signaling in lymphoblastoid cell lines (LCLs). Further results indicate that EBV nuclear antigen 1 (EBNA1) binds to multiple regions within MUC19 and enhances the expression of MUC19. Moreover, sequence alignment has shown intriguing motif homology between the basic repeat unit of MUC19 and EBV genome, suggesting the potential of EBV-specific integration. To conclude, our study maps the genomic perturbations induced by EBV primary infection and offers new insights into the oncogenic roles of MUC19 during EBV latency.

microbiology↗

Discovery of alternative stable states in a synthetic human gut microbial community

AbstractSeveral human-associated microbial communities exist in multiple configurations and can change their composition in response to perturbations, remaining in an altered state even after the perturbation ends. Multistability has been previously proposed to explain this behavior for gut microbiota in particular, but has not been clearly demonstrated experimentally. Here, we first investigated the life history strategies of three common human gut bacteria to identify mechanisms driving alternative states. We then used this data to build and parameterize a kinetic model, which predicted that alternative states emerge due to phenotype switching between subpopulations of the same species. Perturbation experiments supported these predictions, and confirmed the existence of alternative states. Finally, simulations showed that phenotype switching can also explain alternative states in larger communities. Thus, a transient perturbation combined with metabolic flexibility is sufficient for alternative communities to emerge, implying that they are not necessarily explained by differences between individuals. One-Sentence SummaryWe demonstrate the existence of alternative states in a human gut microbial community and propose phenotype switching as a mechanism explaining their emergence.

microbiology↗

Chaperonin TRiC bridges radial spokes for folding proteins locally translated in mammalian sperm flagella

As animals evolved from external to internal fertilization, sperm flagella, which once transiently propelled sperm in water to reach nearby eggs, developed to beat for days or even longer within the female reproductive tract. How flagella were remodeled accordingly remains unclear. Unlike externally fertilizing zebrafish and sea urchin, mammalian sperm flagella feature a unique barrel-shaped bridge between axonemal radial spokes RS1 and RS2, though its components and function remain unknown. Here, using cryo-EM and cryo-ET combined with mass spectrometry and immunofluorescence staining, we reveal that this RS1-RS2 barrel (RRB) in mammalian sperm flagella is a group II chaperonin TRiC/CCT. We purified and resolved the unforeseen cryo-EM structure of TRiC from bovine sperm flagella, discovering that flagella TRiC contains the testis-specific CCT6B subunit. Additionally, we resolved the cryo-ET map of mouse sperm flagella RSs, containing the RRB, achieving unprecedented local resolution of 10-14 [A]. The in-situ RRB map displays two extra densities within its chambers in a polarized manner, suggesting the presence of folding substrates and a co-chaperone (likely phosducin-like 2). Notably, mammalian flagella also contain components of translation machineries and actively synthesize proteins. Our results suggest that the RRB TRiC folds locally translated proteins to sustain mammalian flagella, providing new insights into flagellar remodeling in internally fertilizing species. Our findings also shed lights on male fertility and potential treatments for infertility.

biophysics↗

Unveiling the functional heterogeneity of endogenous tissue extracellular vesicles in skeletal muscle through multi-omics

Extracellular vesicles (EVs) have emerged as promising tools for the development of disease biomarkers and therapeutics because they can transfer various bioactive cargos between cells in vivo. A better understanding of the heterogeneous properties of EVs in vivo may provide insights into their biological roles and clinical translation potential. As a proof-of-concept, we report that different EV subpopulations from skeletal muscle tissues have distinct composition signatures and diverse biological effects on recipient cells. Multiple cell types (e.g., myoblasts and endothelial cells (ECs)) can contribute to the pool of muscle tissue-derived EVs, and large EVs (L-EVs) are enriched with proteins related to metabolic regulation, whereas small EVs (S-EVs) are enriched with original muscle cell-specific proteins related to muscle function regulation. Compared with L-EVs, S-EVs exhibited abundant surface proteins and higher cell uptake rates. Moreover, L-EVs and S-EVs can induce diverse changes in global gene expression, metabolic patterns and some cellular behaviors (e.g., proliferation and differentiation) in recipient cells. These results suggest that different EV subpopulations might control tissue hemostasis in a coordinated manner and suggest the importance of reconsidering their favorable role in future applications (e.g., S-EVs for biomarker discovery and L-EVs for metabolic intervention). This study highlights the functional heterogeneity of tissue-derived EVs in vivo, and the selection of an ideal EV subset on the basis of its specific biological properties may be a promising strategy for developing more precise biomarkers or tailored EV therapies for regenerative medicine. Graphic abstract O_FIG O_LINKSMALLFIG WIDTH=200 HEIGHT=60 SRC="FIGDIR/small/624461v1_ufig1.gif" ALT="Figure 1"> View larger version (23K): org.highwire.dtl.DTLVardef@6a9a0forg.highwire.dtl.DTLVardef@a86cbforg.highwire.dtl.DTLVardef@17b8680org.highwire.dtl.DTLVardef@bb718d_HPS_FORMAT_FIGEXP M_FIG C_FIG SignificanceExtracellular vesicles (EVs) are emerging as important tools for diagnostics, therapeutics, and prognostics in various diseases. Understanding the inherent heterogeneity of EVs is crucial, as distinct subpopulations function differently. While extensive research focuses on EVs derived from cell supernatants, endogenous tissue EVs can more accurately reflect the pathophysiological characteristics of their originating cells. Here, we propose different tissue-EV subpopulations coordinately regulate tissue homeostasis. Small EVs with tissue-specific signatures show promise for biomarker development, while large EVs with metabolic signatures are suitable for metabolic interventions. Additionally, small EVs with enhanced surface proteins are ideal for targeted delivery. This work highlights the importance of selecting tissue-EV subpopulations based on their unique properties for developing precise biomarkers and tailored therapies in regenerative medicine.

cell biology↗

Engineered mitochondrial A-to-G editors with enhanced efficiency and targeting scope

Mitochondrial base editing is a powerful technology, but the current A-to-G mitochondrial DNA (mtDNA) base editors are reluctant to achieve high efficiency, which is critical for mtDNA engineering. Through laboratory evolution, TadA-8e variants were discovered with substantially increased activity and expanded targeting compatibility, especially for previously unfavorite sequence contexts, when applied to both nuclear and mitochondrial ABEs. Further engineering of the mtDNA editors (eTd-mtABEs) dramatically reduced both DNA and RNA off-targeting effects and enhanced strand-selective A-to-G editing with substitution of DddA to DNA nickases. Moreover, the eTd-mtABEs induced up to 145-fold editing frequencies compared to previous mtDNA adenine base editors in rat cells, and installed targeted mutations in all injected rat embryos with up to 74% efficiency in founders, resulting generation of SNHL and Leigh syndrome models with severe defects. It suggests that eTd-mtABEs are promising mtDNA engineering technology for basic research and for translational studies. HighlightsO_LIEngineered TadA variants enhance nuclear and mitochondrial ABE activity in all sequence contexts. C_LIO_LIAdditional mutations in eTd-mtABEs further minimize both DNA and RNA off-targeting effects. C_LIO_LIEngineered TadA variants are compatible to DNA nickase assisted strand-selective mtDNA editing. C_LIO_LIeTd-mtABEs enable highly efficient generation of rat mtDNA disease models with severe phenotypes. C_LI

bioengineering↗

Oncogene-induced senescence and senescence-associated secretory phenotype (SASP) determine the efficacy of palbociclib in PIK3CA mutated colorectal cancer

Palbociclib is an excellent CDK4/6 inhibitor, but its clinical application is mainly limited to the treatment of advanced ER+/HR+ and HER2- breast cancer. Its efficacy in colorectal cancer (CRC) is evaluated in multiple trials and so far remains undetermined. We found that the PIK3CA-mutant CRC cells were insensitive to palbociclib treatment compared with the PIK3CA wild-type counterparts, and they were in an OIS (oncogene-induced senescence) state which was predisposed to a strong senescence-associated secretory phenotype (SASP) upon treatment. These senescent cells excessively secreted various SASP factors LCN2, and ultimately caused palbociclib-resistance via upregulation of EGFR in the non-senescent CRC cells. Importantly, a drug combination screen identified that erlotinib could synergize with palbociclib to overcome the SASP-induced resistance. Overall, we found that PIK3CA mutation-induced senescence compromised the efficacy of palbociclib treatment in CRC but co-targeting EGFR could minimize the OIS-associated side effects while preserving the beneficial effects.

cancer biology↗

Morphological brain alterations and morphological brain network disorganizations in heroin and methamphetamine abstinent patients

Heroin and methamphetamine are the two common types of drugs abused, which poses significant health risks. However, the neural mechanisms underlying the effects of drug addiction on human brain are unclear. In this study, we collected T1-weighted magnetic resonance imaging data from 26 heroin abstinent (HA) patients, 24 methamphetamine abstinent (MA) patients and 32 healthy controls. Four surface-based morphological features including cortical thickness (CT), fractal dimension (FD), gyrification index (GI), and sulcal depth (SD) were calculated, and further used to construct the morphological brain networks. We observed the common CT reductions of the right TE 1.0 and TE 1.2 and SD reductions of the right intermediate lateral area 20 for HA and MA patients, HA-specific CT reductions in the left area 2, and the MA-specific GI reductions in the left medial area 6 and right dorsomedial parietooccipital sulcus. For the morphological brain networks, HA patients exhibited the global disorganizations (higher shortest path length) in CT-based networks, whereas MA patients showed the disrupted nodal efficiency of the left medial area 38 in CT-based networks, the right caudal area 7 in GI-based networks, and the right inferior occipital gyrus in SD-based networks. Furthermore, the altered SD of HA patients and disrupted nodal efficiency of MA patients were associated with drug abuse-related clinical variables. Our findings suggest the morphological index-dependent effects of drug addiction on human brain morphology, and indicate the differential neural mechanism underlying heroin and methamphetamine abuses which attack the global and local information transfer of morphological brain networks, respectively.

neuroscience↗

Surface remodeling and inversion of cell-matrix interactions underlies community recognition and dispersal in Vibrio cholerae biofilms

Biofilms are ubiquitous surface-associated bacterial communities embedded in an extracellular matrix. While it is commonly assumed that biofilm-dwelling cells are glued together by the matrix, how the cell-matrix interaction depends on the specific biochemistry of the matrix components and how this interaction varies during biofilm growth remains unclear. Here, we investigated cell-matrix interactions in Vibrio cholerae (Vc), the causative agent of cholera. We combine genetics, microscopy, simulation, and biochemical tools to show that Vc cells are not attractive to Vibrio polysaccharide (VPS), the main matrix component, but they can be bridged with each other and to the VPS network through crosslinking by Bap1. Downregulation of VPS and surface trimming by the polysaccharide lyase RbmB cause surface remodeling as biofilms age, shifting the nature of cell-matrix interactions from attractive to repulsive and facilitating cell dispersal as aggregated groups. Our results suggest a new conceptual model in understanding the intricate cell-matrix interaction as the major driver for biofilm development, which is potentially generalizable to certain other biofilm-forming species and exopolysaccharides.

biophysics↗

TomoScore: A Neural Network Approach for Quality Assessment of Cellular cryo-ET

Electron cryo-tomography (cryoET) is a powerful imaging tool that allows three-dimensional visualization of subcellular and molecular architecture without chemical fixation. Tomogram quality varies widely, particularly during large high-throughput data collections, and the most common strategy for initial quality assessment is empirical judgment by an expert. Tomograms are collected for two distinct purposes: 1) Annotation of subcellular features and cellular morphology, typically performed at lower magnifications and higher defocus. 2) Subtomogram averaging, generally at higher magnifications and closer to focus. For the first purpose, contrast and the ability to distinguish cellular features of interest are key, whereas for subtomogram averaging, recoverable signal at high resolution is the key factor. We have developed "TomoScore" a deep-learning based tomogram quality metric to assess the suitability of individual tomograms for cellular annotation based on the scale of features which can be distinguished. We further explore the relationship between accumulated electron dose and resulting quality, suggesting an optimum dose range for cryoET data collection. Overall, our study streamlines data processing and reduces the need for human involvement during pre-selection for tomogram segmentation.

biophysics↗