Proteins, as the primary executors of physiological activity, serve as a key factor in disease diagnosis and treatment. Research into their structures, functions, and interactions is essential to better understand disease mechanisms and potential therapies. DeepMind's AlphaFold2, a deep-learning protein structure prediction model, has proven to be remarkably accurate, and it is widely employed in various aspects of diagnostic research, such as the study of disease biomarkers, microorganism pathogenicity, antigen-antibody structures, and missense mutations.
View Article and Find Full Text PDFFeeding behavior, the most fundamental physiological activity, is controlled by two opposing groups of factors, orexigenic and anorexigenic factors. The sulfakinin family, an insect analogue of the mammalian satiety factor cholecystokinin (CCK), has been shown to suppress food intake in various insects. Nevertheless, the mechanisms through which sulfakinin regulates feeding behavior remain a biological question.
View Article and Find Full Text PDFSheng Wu Gong Cheng Xue Bao
May 2024
Protein structure prediction is an important research field in life sciences and medicine, and it is also a key application scenario of artificial intelligence in scientific research. AlphaFold2 is a protein structure prediction system developed by DeepMind based on deep learning, capable of efficiently generating the atomic-scale spatial structure of a protein from the amino acid sequence. It has demonstrated superior performance in the prediction of protein structures since its inception, thus attracting much attention and research.
View Article and Find Full Text PDFRespiratory infectious viruses, including SARS-CoV-2, undergo rapid genetic evolution, resulting in diverse subtypes with complex mutations. Detecting and differentiating these subtypes pose significant challenges in respiratory virus surveillance. To address these challenges, we integrated ARMS-PCR with molecular beacon probes, allowing selective amplification and discrimination of subtypes based on adjacent mutation sites.
View Article and Find Full Text PDFBiochim Biophys Acta Mol Basis Dis
April 2024
CCHamides are newly identified insect neuropeptides, which are widely occurring in most insects. However, our knowledge about their signaling characteristics and physiological roles is still limited. Here, we cloned two full-length cDNAs encoding putative CCHamide receptors, Bombyx neuropeptide GPCR A14 (BNGR-A14) and -A15 (BNGR-A15), from the brain of B.
View Article and Find Full Text PDFRYamides constitute a novel family of neuropeptides newly identified in insects, and play important roles in regulating a variety of physiological processes. However, the signaling characteristics and physiological actions of RYamide signaling system remain largely unknown. In the present study, we cloned the full-length complementary DNA of the RYamide receptor BNGR-A19 from Bombyx mori larvae.
View Article and Find Full Text PDFBiochim Biophys Acta Mol Cell Res
August 2020
Alternative splicing enables G protein-coupled receptor (GPCR) genes to greatly increase the number of structurally and functionally distinct receptor isoforms. However, the functional role and relevance of the individual GPCR splice variants in regulating physiological processes are still to be assessed. A naturally occurring alternative splice variant of Bombyx CAPA-PVK receptor, BomCAPA-PVK-R1-Δ341, has been shown to act as a dominant-negative protein to regulate cell surface expression and function of the canonical CAPA-PVK receptor.
View Article and Find Full Text PDFBiochim Biophys Acta Mol Cell Res
June 2020
Tachykinin signaling system is present in both vertebrates and invertebrates, and functions as neuromodulator responsible for the regulation of various physiological processes. In human, the internalization of G protein-coupled receptors has been extensively characterized; however, the insect GPCR internalization has been rarely investigated. Here, we constructed two expression vectors of Bombyx tachykinin-related peptide receptor (BmTKRPR) fused with Enhanced Green Fluorescent Protein (EGFP) at the C-terminal end for direct visualization of receptor expression, localization, and trafficking in cultured mammalian HEK293 and insect Sf21 cells.
View Article and Find Full Text PDFThe natural colorful cuticles of insects play important roles in many physiological processes. Pigmentation is a physiological process with a complex regulatory network whose regulatory mechanism remains unclear. Bombyx mori pigmentation mutants are ideal materials for research on pigmentation mechanisms.
View Article and Find Full Text PDFDysregulation of microRNAs (miRNAs) contributes to epithelial-mesenchymal transition (EMT) of cancer, but the pathological roles of miRNAs in airway EMT of lung diseases remains largely unknown. We performed sequencing and real-time PCR analysis of the miRNA expression profile of human airway epithelial cells undergoing EMT, and revealed miR-133a to be one of the most common up-regulated miRNAs. MiR-133a was previously reported to be persistently up-regulated in airway epithelial cells of smokers.
View Article and Find Full Text PDFCAPA peptides, such as periviscerokinin (PVK), are insect neuropeptides involved in many signaling pathways controlling, for example, metabolism, behavior, and reproduction. They are present in a large number of insects and, together with their cognate receptors, are important for research into approaches for improving insect control. However, the CAPA receptors in the silkworm () insect model are unknown.
View Article and Find Full Text PDFIn insects, molting and metamorphosis are strictly regulated by ecdysteroids. Ecdysteroid synthesis is positively or negatively controlled by several neuropeptides. The prothoracicostatic peptide (PTSP) BmPTSP (Bombyx mori prothoracicostatic peptide), isolated from the larval brain of B.
View Article and Find Full Text PDFTachykinins constitute one of the largest peptide families in the animal kingdom and exert their diverse actions via G protein-coupled receptors (GPCRs). In this study, the Bombyx tachykinin-related peptides (TKRPs) were identified as specific endogenous ligands for the Bombyx neuropeptide GPCR A24 (BNGR-A24) and thus designated BNGR-A24 as BmTKRPR. Using both mammalian cell line HEK293 and insect cell line Sf21, further characterization demonstrated that BmTKRPR was activated, thus resulting in intracellular accumulation of cAMP, Ca(2+) mobilization, and ERK1/2 phosphorylation in a Gs and Gq inhibitor-sensitive manner.
View Article and Find Full Text PDFThe pineal gland hormone melatonin exerts its regulatory roles in a variety of physiological and pathological responses through two G protein-coupled receptors, melatonin receptor type 1 (MT1) and melatonin receptor type 2 (MT2), which have been recognized as promising targets in the treatment of a number of human diseases and disorders. The MT1 receptor was identified nearly 20 years ago; however, the molecular mechanisms by which MT1-mediated signaling affects physiology remain to be further elucidated. In this study, using HEK293 cells stably expressing the human MT1 receptor, melatonin induced a concentration-dependent activation of extracellular signal-regulated kinase 1 and 2 (ERK1/2).
View Article and Find Full Text PDFMembers of the mammalian neuropeptide Y (NPY) family serve as neurotransmitters and contribute to a diversity of physiological functions. Although neuropeptide F (NPF), the NPY-like orthologs from insects, have been identified, the NPF receptors and their signaling and physiological functions remain largely unknown. In this study, we established the stable and transient functional expression of a Bombyx orphan G protein-coupled receptor, BNGR-A4, in both mammalian HEK293 and insect SF21 cells.
View Article and Find Full Text PDFThe cAMP response element binding protein, CREB, is a G protein-coupled receptor (GPCR) signal-activated transcription factor implicated in the control of many biological processes. In the current study, we constructed a cAMP response element (CRE)-driven luciferase assay system for GPCR characterization in insect cells. Our results indicated that Gs-coupled Bombyx adipokinetic hormone receptor (AKHR) and corazonin receptor could effectively initiate CRE-driven luciferase transcription, but forskolin, a reagent widely used to activate adenylyl cyclase in mammalian systems, failed to induce luciferase activity in insect cells co-transfected with a CRE-driven reporter construct upon agonist treatment.
View Article and Find Full Text PDFThe major effects of cannabinoids and endocannabinoids are mediated via two G protein-coupled receptors, CB1 and CB2, elucidation of the mechanism and structural determinants of the CB2 receptor coupling with G proteins will have a significant impact on drug discovery. In the present study, we systematically investigated the role of the intracellular loops in the interaction of the CB2 receptor with G proteins using chimeric receptors alongside the characterization of cAMP accumulation and ERK1/2 phosphorylation. We provided evidence that ICL2 was significantly involved in G protein coupling in coordination with the C-terminal end.
View Article and Find Full Text PDFCorazonin, an undecapeptide neurohormone sharing a highly conserved amino acid sequence across Insecta, plays different physiological roles in the regulation of heart contraction rates, silk spinning rates, the induction of dark color and morphometric phase changes, and ecdysis. Corazonin receptors have been identified in Drosophila melanogaster, Manduca sexta, and Musca domestica. However, detailed information on the signaling and major physiological functions of corazonin and its receptor is largely unknown.
View Article and Find Full Text PDFAdipokinetic hormones (AKHs) are the best studied insect neuropeptides with the function of mobilizing lipids and carbohydrates during energy-expensive activities and modulating fundamental physiological processes, such as sugar homeostasis, lipid metabolism, and reproduction. Three distinct cDNAs encoding the prepro-Bombyx AKH1-3 have been cloned and confirmed by mass spectrometric methods. Our previous research suggested the Bombyx AKH receptor is activated by AKH1 and AKH2 with high affinity but by AKH3 with quite low affinity.
View Article and Find Full Text PDFNeuropeptides of the adipokinetic hormone (AKH) family play important roles in insect hemolymph sugar homeostasis, larval lipolysis and storage-fat mobilization. Our previous studies have shown that the adipokinetic hormone receptor (AKHR), a Gs-coupled receptor, induces intracellular cAMP accumulation, calcium mobilization and ERK1/2 phosphorylation upon agonist stimulation. However, the underlying molecular mechanisms that regulate the internalization and desensitization of AKHR remain largely unknown.
View Article and Find Full Text PDFNeuropeptides of the adipokinetic hormone (AKH) family are among the best studied hormone peptides. They play important roles in insect hemolymph sugar homeostasis, larval lipolysis, and storage-fat mobilization. Mechanistic investigations have shown that, upon AKH stimulation, adipokinetic hormone receptor (AKHR) couples to a Gs protein and enhances adenylate cyclase activity, leading to intracellular cAMP accumulation.
View Article and Find Full Text PDFG protein-coupled receptors (GPCRs) are the largest and most versatile family of transmembrane receptors in the cell, occupying the highest hierarchical positions in the regulation of many physiological processes. Although they have been extensively studied in a number of model insects, there have been few investigations of GPCRs in large Lepidopterans, such as Bombyx mori, an organism that provides a means to perform detailed tissue expression analyses, which may help to characterize GPCRs and their ligands. In addition, B.
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