Biology subjects

Cheng, C.

Publications and source records attributed to Cheng, C..

At least 55 records · Page 3Linked to original sources

bioRxiv2024

The Mitochondrial Brown Adipose Tissue Maintenance Factor Nipsnap1 Interfaces Directly with the Beta-Oxidation Protein Machinery.

BackgroundThe activation of brown adipose tissue (BAT) is associated with improved metabolic health in humans. We previously identified the mitochondrial protein 4-Nitrophenylphosphatase Domain and Non-Neuronal SNAP25-Like 1 (Nipsnap1) as a novel regulatory factor that integrates with lipid metabolism and is critical to sustain the long-term activation of BAT, but the precise mechanism and function of Nipsnap1 is unknown. ObjectivesDefine how the regulatory factor Nipsnap1 integrates with lipid metabolism. MethodsWe generated adeno-associated viral (AAV) constructs that overexpress Nipsnap1 in the thermogenic fat of mice. We then measured both whole-body and cellular mitochondrial metabolism and mapped the first Nipsnap1 interacting protein-protein network. ResultsHerein, we show that adipose-specific overexpression of Nipsnap1 in mice increases energy expenditure through the utilization of lipids as an energy substrate. The increase in energy expenditure results in reduced weight gain. Additionally, we show that Nipsnap1 overexpression in primary adipocytes increases lipid beta-oxidation. Moreover, we mapped the first protein- protein network of Nipsnap1 in brown adipocytes and show that Nipsnap1 interacts with proteins that regulate both peroxisomal and mitochondrial fatty acid beta-oxidation. ConclusionThis study elucidates a mechanistic function of Nipsnap1 in thermogenic fat where Nipsnap1 facilitates a functional connection between peroxisomal and mitochondrial beta-oxidation pathways. By enhancing lipid utilization as energy substrates, Nipsnap1 plays a pivotal role in sustaining thermogenic fat activation to increase energy expenditure. These findings underscore the potential of Nipsnap1 as a therapeutic target for metabolic health.

cell biology↗

bioRxiv2024

Accurate prediction of CRISPR editing outcomes in somatic cell lines and zygote with few-shot learning

The CRISPR-Cas system has revolutionized gene editing, while its outcome prediction remains unsatisfactory, especially in new cell states due to their distinct DNA repair preferences. In this study, we introduce inDecay, a flexible system for predicting CRISPR editing outcomes from target sequence, returning probabilities of nearly the full spectrum of indel events. Uniquely, inDecay utilizes informative and parameter-efficient features for each indel event and incorporates cell-type-specific repair preferences through a multi-stage design. While both inDecay and existing methods achieve accurate results for prediction within cell lines, only inDecay with transfer learning can retain the high performance for cross-cell line prediction. We then applied inDecay to mouse embryo editing using our newly generated data and observed remarkable accuracy by including as few as 30 fine-tuning embryonic samples. Notably, inDecay is the first software to predict embryonic editing. Therefore, our few-shot learning-supported system may accelerate guide RNA prioritization in mouse model generation, mammal embryonic gene editing, and cellular therapeutics.

bioinformatics↗

bioRxiv2024

Risk factors, prognostic factors, and nomograms for distant metastasis in patients with triple-negative breast cancer: a population-based study

BackgroundTriple-negative breast cancer (TNBC) is associated with a poor prognosis, higher invasiveness compared to other breast cancer variants, and limited treatment options. Due to the lack of conventional treatment methods, TNBC patients are prone to distant metastasis. The purpose of this study is to evaluate the clinical and pathological characteristics of TNBC patients, predict the impact of risk factors on their prognosis, and establish a predictive model to assist doctors in treating TNBC patients and improving their outcomes. MethodsWe conducted a retrospective study on patients with TNBC from 2010 to 2015 in the Surveillance, Epidemiology, and End Results (SEER) database. We gathered tumor characteristics and treatment data from these patients. Univariate and multivariate logistic regression analyses were employed to identify independent risk factors for distant metastasis in TNBC patients, while univariate and multivariate Cox proportional hazards regression analyses were utilized to determine independent prognostic factors for TNBC patients with distant metastasis. Based on these factors, a new nomogram was constructed, and patients were categorized into high and low-risk groups using the nomogram scores. The prognosis of the patients was analyzed using Kaplan-Meier (K-M) survival analysis. ResultsThis study enrolled a total of 16,959 patients with TNBC, among whom 730 (4.3%) had distant metastasis at the time of diagnosis. Independent risk factors for distant metastasis in TNBC patients encompass being married, having an invasive lobular carcinoma (ILC) pathology, advanced T stage, advanced N stage, no radiotherapy, no surgery, and tumor size exceeding 50mm. The area under the curve (AUCs) for the training set and validation set were 0.892 and 0.907, respectively. The independent prognostic factors for patients with distant metastasis were being unmarried (P < 0.001), not undergoing surgery (P < 0.001), and not receiving chemotherapy (P < 0.001). The AUCs for the training set at 12, 36, and 60 months were 0.751, 0.709, and 0.691, respectively, while the AUCs for the validation set at 12, 36, and 60 months were 0.690, 0.690, and 0.732, respectively. The AUCs for the extended test set at 12, 36, and 60 months were 0.741, 0.727, and 0.718 respectively. The results of the calibration curve, decision curve analysis (DCA), and K-M survival curve confirm that both nomograms can accurately predict the occurrence of distant metastasis and prognosis in TNBC patients. ConclusionWe constructed two nomograms to predict distant metastasis risk in TNBC patients and prognosis in patients with distant metastasis. Our findings suggest that they could serve as effective predictive tools and may assist in clinical decision-making.

cancer biology↗

bioRxiv2024

Small molecule oxybutynin rescues proliferative capacity of complex III-defective MPCs

Mitochondrial disease encompasses a group of genetically inherited disorders hallmarked by an inability of the respiratory chain to produce sufficient ATP. These disorders present with multisystemic pathologies that predominantly impact highly energetic tissues such as skeletal muscle. There is no cure or effective treatment for mitochondrial disease. We have discovered a small molecule known as oxybutynin that can bypass Complex III mitochondrial dysfunction in primary murine and human skeletal muscle progenitor cells (MPCs). Oxybutynin administration improves MPC proliferative capacity, enhances cellular glycolytic function, and improves myotube formation. Mechanistically, results from our isothermal shift assay indicates that oxybutynin interacts with a suite of proteins involved in mRNA processing which then trigger the upregulation biological pathways to circumvent CIII mitochondrial dysfunction. Taken together, we provide evidence for the small molecule oxybutynin as a potential therapeutic candidate for the future treatment of CIII mitochondrial dysfunction.

cell biology↗

bioRxiv2024

A tumor-secreted protein utilizes glucagon release to cause host wasting

Tumor-host interaction plays a critical role in malignant tumor-induced organ wasting across multiple species. Despite known regulation of regional wasting of individual peripheral organs by tumors, whether and how tumors utilize critical host catabolic hormone(s) to simultaneously induce systemic host wasting, however, is largely unknown. Using the conserved yki3SA-tumor model in Drosophila, we discovered that tumors increase the production of adipokinetic hormone (Akh), a glucagon-like catabolic hormone, to cause systemic host wasting, including muscle dysfunction, lipid loss, hyperglycemia, and ovary atrophy. We next integrated RNAi screening and Gal4-LexA dual expression system to identify that yki3SA-gut tumors secrete Pvf1 to remotely activate its receptor Pvr in Akh-producing cells (APCs), ultimately promoting Akh production. The underlying molecular mechanisms involved the Pvf1-Pvr axis that triggers Mmp2-dependent ECM remodeling of APCs and enhances innervation from the excitatory cholinergic neurons. Interestingly, we also confirmed the similar mechanisms governing tumor-induced glucagon release and organ wasting in mammals. Blockade of either glucagon or PDGFR (homolog of Pvr) action efficiently ameliorated organ wasting in the presence of malignant tumors. Therefore, our results demonstrate that tumors remotely promote neural-associated Akh/glucagon production via Pvf1-Pvr axis to cause systemic host wasting.

physiology↗

bioRxiv2024

Heterogeneity and plasticity of the naive CD4+ T cell compartment

While naive CD4+ T cells have historically been considered a homogenous population, recent studies have provided evidence that functional heterogeneity exists within this population. Using single cell RNA sequencing (scRNAseq), we identify five transcriptionally distinct naive CD4+ T cell subsets that emerge within the single positive stage in the thymus: a quiescence cluster (TQ), a memory-like cluster (TMEM), a TCR reactive cluster (TTCR), an IFN responsive cluster (TIFN), and an undifferentiated cluster (TUND). Elevated expression of transcription factors KLF2, Mx1, and Nur77 within the TQ, TIFN, and TMEM clusters, respectively, allowed enrichment of these subsets for further analyses. Functional studies using sorted cells revealed that naive T cell subsets have distinctive functional biases upon stimulation. Furthermore, treatment of mice with inflammatory stimuli imparted a state of reduced responsiveness on naive T cells, evidenced by a reduction in cytokine production ex vivo. In human lupus patients, naive CD4+ T cell cluster frequencies were distorted, with the TIFN cluster expanding proportionately with disease score. Our data show that naive T cells are influenced by host environment, with functional consequences manifesting upon activation. These findings highlight a need to explore how naive T cells can become distorted in cancer, autoimmunity, and infectious diseases. SummaryThis study describes the transcriptional heterogeneity of murine and human naive CD4+ T cells as comprising of multiple discrete clusters that impact CD4+ T cell fate and trajectories. Naive CD4+ T cells experiencing inflammatory environments exhibit an altered transcriptional state that influences their functional trajectory.

immunology↗

bioRxiv2024

AQP1- A regulatory factor associated with brown adipose tissue silencing

The activation of non-shivering thermogenesis (NST) in brown adipose tissue (BAT) by environmental cold challenge yields strong metabolic benefit in the face of diet-induced obesity (DIO). Yet, a critical barrier to leveraging brown fat NST for therapeutic use against metabolic disease is that BAT is silenced and inactive at physiological ambient temperature conditions in humans. The mechanisms that govern this silencing process remain poorly understood. Here, we identified a putative BAT-silencing factor, aquaporin-1 (AQP1), in brown fat from wild-type (WT) mice via proteomics analysis. We generated the first BAT-specific AQP1 knockout mice (AQP1-KO) and revealed that AQP1-KO could activate NST under BAT silencing environmental conditions and that the AQP1-KO mice were significantly protected against DIO and metabolic dysfunction compared to Flox controls. We found that AQP1-KO mice on high fat diet (HFD) had reduced weight gain through reductions in fat mass, improved glucose tolerance, and increased whole body energy expenditure compared to Flox control mice. Mechanistically, we show that AQP1 ablation in mice had upregulated gene expression related to the electron transport chain (ETC) and mitochondrial translation contributing to the activation of NST under BAT environmental silenced conditions. Significance StatementNovel strategies to combat obesity-associated metabolic dysfunction are urgently needed to curb the growing obesity epidemic. Investigation of brown adipose tissue (BAT) silencing mechanisms may reveal novel therapeutic targets that when ablated, can activate BAT to increase energy expenditure and protect subjects against the metabolic dysfunction associated with obesity. We have identified Aquaporin 1 (AQP1) as a putative BAT silencer regulatory factor and show through the generation of the first BAT-specific aquaporin-1 knockout (AQP1-KO) mouse that BAT can be activated under environmental silencing conditions. We further show that these mice are protected against diet-induced obesity, with improved glucose tolerance, and increased energy expenditure. These findings highlight AQP1 as a promising therapeutic target in the emerging research field of BAT silencers.

molecular biology↗

bioRxiv2024

High-Dimensional Mediation Analysis with Network Mediators: Applications to Pediatric Acute Lymphoblastic Leukemia.

Acute lymphoblastic leukemia (ALL) is the most common childhood cancer, with survivors frequently experiencing long-term neurocognitive morbidities. Here, we utilize the TOTXVI clinical trial data to elucidate the mechanisms underlying treatment-related neurocognitive side effects in pediatric ALL patients by incorporating brain connectivity network data. To enable such analysis, we propose a high-dimensional mediation analysis method with a novel network mediation structural shrinkage (NMSS) prior, which is particularly suited for analyzing high-dimensional brain structural connectivity network data that serve as mediators. Our method is capable of addressing the structural dependencies of brain connectivity networks including sparsity, effective degrees of nodes, and modularity, yielding accurate estimates of the high-dimensional coefficients and mediation effects. We demonstrate the effectiveness and superiority of the proposed NMSS method through simulation studies and apply it to the TOTXVI data, revealing significant mediation effects of brain connectivity on visual processing speed directed by IT intensity. The findings shed light on the potential of targeted interventions to mitigate neurocognitive deficits in pediatric ALL survivors.

cancer biology↗

bioRxiv2024

Bootstrap Evaluation of Association Matrices (BEAM) for Integrating Multiple Omics Profiles with Multiple Outcomes

MotivationLarge datasets containing multiple clinical and omics measurements for each subject motivate the development of new statistical methods to integrate these data to advance scientific discovery. ModelWe propose bootstrap evaluation of association matrices (BEAM), which integrates multiple omics profiles with multiple clinical endpoints. BEAM associates a set omic features with clinical endpoints via regression models and then uses bootstrap resampling to determine statistical significance of the set. Unlike existing methods, BEAM uniquely accommodates an arbitrary number of omic profiles and endpoints. ResultsIn simulations, BEAM performed similarly to the theoretically best simple test and outperformed other integrated analysis methods. In an example pediatric leukemia application, BEAM identified several genes with biological relevance established by a CRISPR assay that had been missed by univariate screens and other integrated analysis methods. Thus, BEAM is a powerful, flexible, and robust tool to identify genes for further laboratory and/or clinical research evaluation. AvailabilitySource code, documentation, and a vignette for BEAM are available on GitHub at: https://github.com/annaSeffernick/BEAMR. The R package is available from CRAN at: https://cran.r-project.org/package=BEAMR. ContactStanley.Pounds@stjude.org Supplementary InformationSupplementary data are available at the journals website.

bioinformatics↗

bioRxiv2024

Does Sex-Differential Gene Expression Drive Sex-Differential Selection in Humans?

Sex differences in human transcriptomes have been argued to drive sex-differential natural selection (SDS). Here, we show that previous evidence supporting this hypothesis has been largely unfounded. We develop a new method to test for a genome-wide relationship between sex differences in expression and selection on expression-influencing alleles (eQTLs). We apply it across 39 human tissues and find no evidence for a general relationship. We offer possible explanations for the lack of evidence, including that it is due in part to eQTL ascertainment bias towards sites under weak selection. We conclude that the drivers of ongoing SDS in humans remain to be identified.

evolutionary biology↗

bioRxiv2024

Deficiency of m6A RNA methylation promotes ZBP1-mediated cell death

m6A RNA methylation suppresses the immunostimulatory potential of endogenous RNA. Deficiency of m6A provokes inflammatory responses and cell death, but the underlying mechanisms remain elusive. Here we showed that the noncoding RNA 7SK gains immunostimulatory potential upon m6A depletion and subsequently activates the RIG-I/MAVS axis to spark interferon (IFN) signaling cascades. Concomitant excess of IFN and m6A deficiency synergistically facilitate the formation of RNA G-quadruplexes (rG4) to promote ZBP1-mediated necroptotic cell death. Collectively, our findings delineate a hitherto uncharacterized mechanism that links m6A dysregulation with ZBP1 activity in triggering inflammatory cell death.

molecular biology↗

bioRxiv2024

Single-cell RNA Sequencing Reveals Methamphetamine Inhibits the Liver Immune Response with Involvement of the Dopamine D1 Receptor

Methamphetamine (METH) is a highly addictive psychostimulant that causes physical and psychological damage and immune system disorder, especially in the liver, which contains a significant number of immune cells. Dopamine, which is a key neurotransmitter in METH addiction and immune regulation, plays a crucial role in this process. In this study, we developed a chronic METH administration model and conducted single-cell RNA sequencing to investigate the effect of METH on liver immune cells and the involvement of the dopamine receptor D1 (DRD1) in this process. Our findings revealed that chronic exposure to METH induced an immune cell shift from Ifitm3+Mac and Ccl5+Mac to Cd14+Mac, and from Fyn+CD4+Teff, CD8+T, and NKT to Fos+CD4+T and Rora+ILC2, along with suppression of multiple immune functional pathways. DRD1 was implicated in the regulation of some of these pathways and the shifts of hepatic immune cells. This research provides valuable insights into the development of therapies aimed at mitigating METH-induced immune impairment.

immunology↗

bioRxiv2024

TimiGP-Response: the pan-cancer immune landscape associated with response to immunotherapy

Accumulating evidence suggests that the tumor immune microenvironment (TIME) significantly influences the response to immunotherapy, yet this complex relationship remains elusive. To address this issue, we developed TimiGP-Response (TIME Illustration based on Gene Pairing designed for immunotherapy Response), a computational framework leveraging single-cell and bulk transcriptomic data, along with response information, to construct cell-cell interaction networks associated with responders and estimate the role of immune cells in treatment response. This framework was showcased in triple-negative breast cancer treated with immune checkpoint inhibitors targeting the PD-1:PD-L1 interaction, and orthogonally validated with imaging mass cytometry. As a result, we identified CD8+ GZMB+ T cells associated with responders and its interaction with regulatory T cells emerged as a potential feature for selecting patients who may benefit from these therapies. Subsequently, we analyzed 3,410 patients with seven cancer types (melanoma, non-small cell lung cancer, renal cell carcinoma, metastatic urothelial carcinoma, hepatocellular carcinoma, breast cancer, and esophageal cancer) treated with various immunotherapies and combination therapies, as well as several chemo- and targeted therapies as controls. Using TimiGP-Response, we depicted the pan-cancer immune landscape associated with immunotherapy response at different resolutions. At the TIME level, CD8 T cells and CD4 memory T cells were associated with responders, while anti-inflammatory (M2) macrophages and mast cells were linked to non-responders across most cancer types and datasets. Given that T cells are the primary targets of these immunotherapies and our TIME analysis highlights their importance in response to treatment, we portrayed the pan-caner landscape on 40 T cell subtypes. Notably, CD8+ and CD4+ GZMK+ effector memory T cells emerged as crucial across all cancer types and treatments, while IL-17-producing CD8+ T cells were top candidates associated with immunotherapy non-responders. In summary, this study provides a computational method to study the association between TIME and response across the pan-cancer immune landscape, offering resources and insights into immune cell interactions and their impact on treatment efficacy.

bioinformatics↗

bioRxiv2024

New isolates refine the ecophysiology of the Roseobacter CHAB-I-5 lineage

The CHAB-I-5 cluster is a pelagic lineage that can comprise a significant proportion of all roseobacters in surface oceans and have predicted roles in biogeochemical cycling via heterotrophy, aerobic anoxygenic photosynthesis (AAnP), CO oxidation, DMSP degradation, and other metabolisms. Though cultures of CHAB-I-5 have been reported, none have been explored and the best known representative, strain SB2, was lost from culture after obtaining the genome sequence. We have isolated two new CHAB-I-5 representatives, strains US3C007 and FZCC0083, and assembled complete, circularized genomes with 98.7% and 92.5% average nucleotide identities with the SB2 genome. Comparison of these three with 49 other unique CHAB-I-5 metagenome-assembled and single-cell genomes indicated that the cluster represents a genus with two species, and we identified subtle differences in genomic content between the two species subclusters. Metagenomic recruitment from over fourteen hundred samples expanded their known global distribution and highlighted both isolated strains as representative members of the clade. FZCC0083 grew over twice as fast as US3C007 and over a wider range of temperatures. The axenic culture of US3C007 occurs as pleomorphic cells with most exhibiting a coccobacillus/vibrioid shape. We propose the name Thalassovivens spotae, gen nov., sp. nov. for the type strain US3C007T.

microbiology↗

bioRxiv2024

Proteome analysis provides insights into sex differences in Holothuria Scabra

Sex-determining mechanism is still ambiguous for sea cucumber Holothuria scabra which only manifests gonochorism in gonad. In this study, proteomic analysis was employed to delineate sex-related proteins and genes in gonads of H. scabra, subsequently validated through Quantitative real-time polymerase chain reaction (qRT-PCR). A total of 5,313 proteins were identified via proteome sequencing. Among these, 817 proteins exhibited expression in both the ovary and testis, with 445 proteins displaying up-regulation and 372 proteins showing down-regulation. Furthermore, 136 and 69 proteins were identified as ovary-specific and testis-specific Differentially Abundant Proteins (DAPs), respectively. For the validation of 75 DAP coding genes, 9 genes were considered to be reliable. Notably, 25 ovary-bias proteins enriched in ribosome pathway strongly indicated the crucial role of ribosome in ovary. And 5S/18S rRNA ratio in H. Scabra may have potencial to establish a nondestructive method to distinguish sexes unambiguously. This study serves to furnish novel evidence pertaining to sex differences in H. scabra.

molecular biology↗

bioRxiv2024

CDK12 Loss Promotes Prostate Cancer Development While Exposing Vulnerabilities to Paralog-Based Synthetic Lethality

Biallelic loss of cyclin-dependent kinase 12 (CDK12) defines a unique molecular subtype of metastatic castration-resistant prostate cancer (mCRPC). It remains unclear, however, whether CDK12 loss per se is sufficient to drive prostate cancer development--either alone, or in the context of other genetic alterations--and whether CDK12-mutant tumors exhibit sensitivity to specific pharmacotherapies. Here, we demonstrate that tissue-specific Cdk12 ablation is sufficient to induce preneoplastic lesions and robust T cell infiltration in the mouse prostate. Allograft-based CRISPR screening demonstrated that Cdk12 loss is positively associated with Trp53 inactivation but negatively associated with Pten inactivation--akin to what is observed in human mCRPC. Consistent with this, ablation of Cdk12 in prostate organoids with concurrent Trp53 loss promotes their proliferation and ability to form tumors in mice, while Cdk12 knockout in the Pten-null prostate cancer mouse model abrogates tumor growth. Bigenic Cdk12 and Trp53 loss allografts represent a new syngeneic model for the study of androgen receptor (AR)-positive, luminal prostate cancer. Notably, Cdk12/Trp53 loss prostate tumors are sensitive to immune checkpoint blockade. Cdk12-null organoids (either with or without Trp53 co-ablation) and patient-derived xenografts from tumors with CDK12 inactivation are highly sensitive to inhibition or degradation of its paralog kinase, CDK13. Together, these data identify CDK12 as a bona fide tumor suppressor gene with impact on tumor progression and lends support to paralog-based synthetic lethality as a promising strategy for treating CDK12-mutant mCRPC.

cancer biology↗

bioRxiv2024

Targeting PIKfyve-driven lipid homeostasis as a metabolic vulnerability in pancreatic cancer

Pancreatic ductal adenocarcinoma (PDAC) subsists in a nutrient-deregulated microenvironment, making it particularly susceptible to treatments that interfere with cancer metabolism1 2. For example, PDAC utilizes and is dependent on high levels of autophagy and other lysosomal processes3-5. Although targeting these pathways has shown potential in preclinical studies, progress has been hampered by the challenge of identifying and characterizing favorable targets for drug development6. Here, we characterize PIKfyve, a lipid kinase integral to lysosomal functioning7, as a novel and targetable vulnerability in PDAC. In human patient and murine PDAC samples, we discovered that PIKFYVE is overexpressed in PDAC cells compared to adjacent normal cells. Employing a genetically engineered mouse model, we established the essential role of PIKfyve in PDAC progression. Further, through comprehensive metabolic analyses, we found that PIKfyve inhibition obligated PDAC to upregulate de novo lipid synthesis, a relationship previously undescribed. PIKfyve inhibition triggered a distinct lipogenic gene expression and metabolic program, creating a dependency on de novo lipid metabolism pathways, by upregulating genes such as FASN and ACACA. In PDAC, the KRAS-MAPK signaling pathway is a primary driver of de novo lipid synthesis, specifically enhancing FASN and ACACA levels. Accordingly, the simultaneous targeting of PIKfyve and KRAS-MAPK resulted in the elimination of tumor burden in a syngeneic orthotopic model and tumor regression in a xenograft model of PDAC. Taken together, these studies suggest that disrupting lipid metabolism through PIKfyve inhibition induces synthetic lethality in conjunction with KRAS-MAPK-directed therapies for PDAC.

cancer biology↗

bioRxiv2024

Evolutionary trajectory of TRPM2 channel activation by adenosine diphosphate ribose and calcium

Ion channel activation upon ligand gating triggers a myriad of biological events and, therefore, evolution of ligand gating mechanism is of fundamental importance. TRPM2, a typical ancient ion channel, is activated by adenosine diphosphate ribose (ADPR) and calcium and its activation has evolved from a simple mode in invertebrates to a more complex one in vertebrates, but the evolutionary process is still unknown. Molecular evolutionary analysis of TRPM2s from more than 280 different animal species has revealed that, the C-terminal NUDT9-H domain has evolved from an enzyme to a ligand binding site for activation, while the N-terminal MHR domain maintains a conserved ligand binding site. Calcium gating pattern has also evolved, from one Ca2+-binding site as in sea anemones to three sites as in human. Importantly, we identified a new group represented by olTRPM2, which has a novel gating mode and fills the missing link of the channel gating evolution. We conclude that the TRPM2 ligand binding or activation mode evolved through at least three identifiable stages in the past billion years from simple to complicated and coordinated. Such findings benefit the evolutionary investigations of other channels and proteins.

evolutionary biology↗