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MedComm Jul 2024The DNA-dependent protein kinase (DNA-PK), catalytic subunit, also known as DNA-PKcs, is complexed with the heterodimer Ku70/Ku80 to form DNA-PK holoenzyme, which is... (Review)
Review
The DNA-dependent protein kinase (DNA-PK), catalytic subunit, also known as DNA-PKcs, is complexed with the heterodimer Ku70/Ku80 to form DNA-PK holoenzyme, which is well recognized as initiator in the nonhomologous end joining (NHEJ) repair after double strand break (DSB). During NHEJ, DNA-PKcs is essential for both DNA end processing and end joining. Besides its classical function in DSB repair, DNA-PKcs also shows multifaceted functions in various biological activities such as class switch recombination (CSR) and variable (V) diversity (D) joining (J) recombination in B/T lymphocytes development, innate immunity through cGAS-STING pathway, transcription, alternative splicing, and so on, which are dependent on its function in NHEJ or not. Moreover, DNA-PKcs deficiency has been proven to be related with human diseases such as neurological pathogenesis, cancer, immunological disorder, and so on through different mechanisms. Therefore, it is imperative to summarize the latest findings about DNA-PKcs and diseases for better targeting DNA-PKcs, which have shown efficacy in cancer treatment in preclinical models. Here, we discuss the multifaceted roles of DNA-PKcs in human diseases, meanwhile, we discuss the progresses of DNA-PKcs inhibitors and their potential in clinical trials. The most updated review about DNA-PKcs will hopefully provide insights and ideas to understand DNA-PKcs associated diseases.
PubMed: 38898995
DOI: 10.1002/mco2.613 -
Horticulture Research Jun 2024Flowers and fruits are the reproductive organs in plants and play essential roles in natural beauty and the human diet. CLAVATA (CLV) signaling has been well...
Flowers and fruits are the reproductive organs in plants and play essential roles in natural beauty and the human diet. CLAVATA (CLV) signaling has been well characterized as regulating floral organ development by modulating shoot apical meristem (SAM) size; however, the signaling molecules downstream of the CLV pathway remain largely unknown in crops. Here, we found that functional disruption of CsCLV3 peptide and its receptor CsCLV1 both resulted in flowers with extra organs and stumpy fruits in cucumber. A heterotrimeric G protein α-subunit (CsGPA1) was shown to interact with CsCLV1. mutant plants derived from gene editing displayed significantly increased floral organ numbers and shorter and wider fruits, a phenotype resembling that of mutants in cucumber. Moreover, the SAM size was enlarged and the longitudinal cell size of fruit was decreased in mutants. The expression of the classical stem cell regulator () was elevated in the SAM, while the expression of the fruit length stimulator () was reduced in the fruit of mutants. Therefore, the Gα-subunit CsGPA1 protein interacts with CsCLV1 to inhibit floral organ numbers but promote fruit elongation, via repressing expression and activating transcription in cucumber. Our findings identified a new player in the CLV signaling pathway during flower and fruit development in dicots, increasing the number of target genes for precise manipulation of fruit shape during crop breeding.
PubMed: 38898960
DOI: 10.1093/hr/uhae110 -
Nature Communications Jun 2024Methaqualone, a quinazolinone marketed commercially as Quaalude, is a central nervous system depressant that was used clinically as a sedative-hypnotic, then became a...
Methaqualone, a quinazolinone marketed commercially as Quaalude, is a central nervous system depressant that was used clinically as a sedative-hypnotic, then became a notorious recreational drug in the 1960s-80s. Due to its high abuse potential, medical use of methaqualone was eventually prohibited, yet it persists as a globally abused substance. Methaqualone principally targets GABA receptors, which are the major inhibitory neurotransmitter-gated ion channels in the brain. The restricted status and limited accessibility of methaqualone have contributed to its pharmacology being understudied. Here, we use cryo-EM to localize the GABA receptor binding sites of methaqualone and its more potent derivative, PPTQ, to the same intersubunit transmembrane sites targeted by the general anesthetics propofol and etomidate. Both methaqualone and PPTQ insert more deeply into subunit interfaces than the previously-characterized modulators. Binding of quinazolinones to this site results in widening of the extracellular half of the ion-conducting pore, following a trend among positive allosteric modulators in destabilizing the hydrophobic activation gate in the pore as a mechanism for receptor potentiation. These insights shed light on the underexplored pharmacology of quinazolinones and further elucidate the molecular mechanisms of allosteric GABA receptor modulation through transmembrane binding sites.
Topics: Receptors, GABA-A; Binding Sites; Cryoelectron Microscopy; Humans; Animals; Etomidate; Propofol; Quinazolinones; Allosteric Regulation; HEK293 Cells; Hypnotics and Sedatives
PubMed: 38898000
DOI: 10.1038/s41467-024-49471-y -
Vaccine Jun 2024Chlamydia is an obligate intracellular bacterial pathogen responsible for disease and infertility across multiple species. Currently vaccines are being studied to help...
Chlamydia is an obligate intracellular bacterial pathogen responsible for disease and infertility across multiple species. Currently vaccines are being studied to help reduce the prevalence of this disease. The main advantage of protein subunit vaccines is their high degree of safety although this is traded off with the requirement for multiple booster doses to achieve complete protection. Although in certain populations the booster dose can be difficult and costly to administer, development of delayed vaccine delivery techniques, such as a vaccine capsule, could be the solution to this problem. One of the main drawbacks in this technology is that the antigen must remain stable at body temperature (37 °C) until release is achieved. Here we elucidate the stability of a recombinant chlamydial major outer membrane protein (MOMP) antigen and assess its antigenic and immunogenic properties after subjecting the antigen to 37 °C for four to six weeks. Through in vitro and in vivo assessment we found that the aged chlamydial MOMP was able to produce equivalent humoral and cell-mediated immune responses when compared with the unaged vaccine. It was also found that vaccines formulated with the aged antigen conferred equivalent protection against a live infection challenge as the unaged antigen. Thus ageing chlamydial MOMP antigens at 37 °C for four to six weeks did not cause any significant structural or antigenic/immunogenic degradation and recombinant C. muridarum MOMP is suitable for use in a delayed vaccine delivery system.
PubMed: 38897891
DOI: 10.1016/j.vaccine.2024.06.015 -
The Journal of Biological Chemistry Jun 2024Progesterone (P), acting via its nuclear receptor (PR), is critical for pregnancy maintenance by suppressing proinflammatory and contraction-associated protein...
Progesterone (P), acting via its nuclear receptor (PR), is critical for pregnancy maintenance by suppressing proinflammatory and contraction-associated protein (CAP)/contractile genes in the myometrium. P/PR partially exerts these effects by tethering to NF-κB bound to their promoters, thereby decreasing NF-κB transcriptional activity. However, the underlying mechanisms whereby P/PR interaction blocks proinflammatory and CAP gene expression are not fully understood. Herein, we characterized CCR-NOT transcription complex subunit 1 (CNOT1) as a P-induced corepressor that also interacts within the same chromatin complex as PR-B. In mouse myometrium increased expression of CAP genes Oxtr and Cx43 at term coincided with a marked decline in expression and binding of endogenous CNOT1 to NF-κB-response elements within the Oxtr and Cx43 promoters. Increased CAP gene expression was accompanied by a pronounced decrease in the enrichment of repressive histone marks and an increase in the enrichment of active histone marks to this genomic region. These changes in histone modification were associated with changes in the expression of corresponding histone-modifying enzymes. Myometrial tissues from P-treated 18.5 dpc pregnant mice manifested increased Cnot1 expression at 18.5 dpc, compared to vehicle-treated controls. In hTERT-HM cells, P4 treatment enhanced CNOT1 expression and its recruitment to NF-κB-response elements within the CX43 and OXTR promoter regions. Furthermore, knockdown of CNOT1 significantly increased the expression of contractile genes. These novel findings suggest that decreased expression and binding of the transcriptional corepressor CNOT1 at the chromatin level near term and associated changes in histone modifications at the OXTR and CX43 promoters contribute to the induction of myometrial contractility leading to parturition.
PubMed: 38897566
DOI: 10.1016/j.jbc.2024.107484 -
ELife Jun 2024The CALHM proteins constitute a family of large pore channels that contains six closely related paralogs in humans. Two family members, CALHM1 and 3, have been...
The CALHM proteins constitute a family of large pore channels that contains six closely related paralogs in humans. Two family members, CALHM1 and 3, have been associated with the release of ATP during taste sensation. Both proteins form heteromeric channels that activate at positive potential and decreased extracellular Ca concentration. Although the structures of several family members displayed large oligomeric organizations of different size, their function has in most cases remained elusive. Our previous study has identified the paralogs CALHM2, 4 and, 6 to be highly expressed in the placenta and defined their structural properties as membrane proteins exhibiting features of large pore channels with unknown activation properties (Drożdżyk et al., 2020). Here, we investigated whether these placental paralogs would form heteromers and characterized heteromeric complexes consisting of CALHM2 and CALHM4 subunits using specific binders as fiducial markers. Both proteins assemble with different stoichiometries with the largest population containing CALHM2 as the predominant component. In these oligomers, the subunits segregate and reside in their preferred conformation found in homomeric channels. Our study has thus revealed the properties that govern the formation of CALHM heteromers in a process of potential relevance in a cellular context.
Topics: Humans; Protein Multimerization; Calcium Channels; HEK293 Cells; Female; Placenta; Protein Conformation
PubMed: 38896440
DOI: 10.7554/eLife.96138 -
Open Biology Jun 2024The transition from oocyte to embryo requires translation of maternally provided transcripts that in is activated by Pan Gu kinase to release a rapid succession of 13...
The transition from oocyte to embryo requires translation of maternally provided transcripts that in is activated by Pan Gu kinase to release a rapid succession of 13 mitotic cycles. Mitotic entry is promoted by several protein kinases that include Greatwall/Mastl, whose Endosulfine substrates antagonize Protein Phosphatase 2A (PP2A), facilitating mitotic Cyclin-dependent kinase 1/Cyclin B kinase activity. Here we show that hyperactive can not only be suppressed by mutants in its Endos substrate but also by mutants in Pan Gu kinase subunits. Conversely, mutants in or which encode a complex that represses hundreds of maternal mRNAs, enhance . Me31B and Trailer Hitch proteins, known substrates of Pan Gu kinase, copurify with Endos. This echoes findings that budding yeast Dhh1, orthologue of Me31B, associates with Igo1/2, orthologues of Endos and substrates of the Rim15, orthologue of Greatwall. derived mutant embryos show reduced Me31B and elevated transcripts for the mitotic activators Cyclin B, Polo and Twine/Cdc25. Together, our findings demonstrate a previously unappreciated conservation of the Greatwall-Endosulfine pathway in regulating translational repressors and its interactions with the Pan Gu kinase pathway to regulate translation and/or stability of maternal mRNAs upon egg activation.
Topics: Animals; Drosophila Proteins; Oocytes; Protein Phosphatase 2; Gene Expression Regulation, Developmental; Protein Biosynthesis; Drosophila melanogaster; Mutation; Female; Protein Serine-Threonine Kinases; Embryo, Nonmammalian; RNA Stability; RNA, Messenger, Stored; DEAD-box RNA Helicases
PubMed: 38896085
DOI: 10.1098/rsob.240065 -
Studies in Mycology Jun 2023(, ) species are common soil-borne fungi, endophytes, epiphytes, and saprotrophs. Sexual morphs of spp were placed in the genus , which was further segregated into the...
(, ) species are common soil-borne fungi, endophytes, epiphytes, and saprotrophs. Sexual morphs of spp were placed in the genus , which was further segregated into the six subgenera , , , , , and . However, with the end of dual nomenclature, became the single depository for sexual and asexual morph-typified species. Species of are typically characterised by penicillate, sporodochial, and, in many cases, dimorphic conidiophores (primary and secondary conidiophores). Primary conidiophores are mononematous, either verticillium-like or narrowly penicillate. The secondary conidiophores generally form imbricate conidial chains that can collapse to slimy masses, particularly on sporodochia. In the present study, we investigated the species diversity within a collection of 420 strains of from the culture collection of, and personal collections at, the Westerdijk Fungal Biodiversity Institute in Utrecht, the Netherlands. Strains were analysed based on their morphological characters and molecular phylogeny. The latter used DNA sequence data of the nuclear ribosomal internal transcribed spacer regions and intervening 5.8S nrDNA (ITS) and partial 28S large subunit (LSU) nrDNA and partial protein encoding genes including the RNA polymerase II second largest subunit (), translation elongation factor 1-alpha () and β-tubulin (). Based on these results, the subgenera , , and are supported within . Furthermore, the genus is resurrected to accommodate the former subgenera and . The close relationship of and is strongly supported as both are inferred phylogenetically as sister-genera. New taxa include 24 new species and 10 new combinations. Recognition of distinguishes species typically forming a reduced perithecial stroma superficially on plant tissue from species in often forming well-developed, through bark erumpent stromata. The patterns of observed perithecial wall anatomies, perithecial wall and stroma interfaces, and asexual morph diversifications described in a previously compiled monograph are used for interpreting ancestral state reconstructions. It is inferred that the common ancestor of and may have formed perithecia superficially on leaves, possessed a perithecial wall consisting of a single region, and formed intercalary phialides in penicilli of conidiophores. Character interpretation may also allow hypothesising that diversification of morphs occurred then in the two genera independently and that the frequently stroma-linked morphs evolved together with the occupation of woody host niches and mycoparasitism. L. Zhao & Crous, L. Zhao & Crous, L. Zhao & Crous, L. Zhao & Crous, L. Zhao & Crous, L. Zhao & Crous, L. Zhao, Crous & Schroers, L. Zhao & Crous, L. Zhao, Crous & Schroers, L. Zhao & Crous, L. Zhao & Crous, L. Zhao, Crous & Schroers, , L. Zhao & Crous, L. Zhao, Crous & Schroers, L. Zhao & Crous, L. Zhao, Crous & Schroers, L. Zhao & Crous, L. Zhao, Crous & Schroers, L. Zhao, Crous & Schroers, L. Zhao & Crous, L. Zhao & Crous, L. Zhao & Crous, L. Zhao & Crous, L. Zhao & Crous. (J.A. Stev.) L. Zhao & Crous, (Y.P. Tan .) L. Zhao & Crous, (Y.P. Tan .) L. Zhao & Crous, (Samuels) L. Zhao, Crous & Schroers, (Schroers) L. Zhao, Crous & Schroers, (Schroers) L. Zhao, Crous & Schroers, (Lechat & J. Fourn.) L. Zhao & Crous, (Samuels) L. Zhao, Crous & Schroers, (Lechat & J. Fourn.) L. Zhao & Crous, (Höhn.) Schroers. W.H. Chen ., H. Yu & Y. Wang, R.H. Perera & K.D. Hyde, (Starbäck) Forin & Vizzini, Prasher & R. Chauhan, R.H. Perera ., (Sacc.) Forin & Vizzini, (J. Luo & W.Y. Zhuang) Z.Q. Zeng & W.Y. Zhuang. J.C. Schmidt ex Link, Bonord. Zhao L, Groenewald JZ, Hernández-Restrepo M, Schroers H-J, Crous PW (2023). Revising and allied genera in . : 205-266. doi: 10.3114/sim.2023.105.03.
PubMed: 38895704
DOI: 10.3114/sim.2023.105.03 -
BioRxiv : the Preprint Server For... Jun 2024G protein-coupled receptors (GPCRs) are efficient Guanine nucleotide exchange factors (GEFs) and exchange GDP to GTP on the Gα subunit of G protein heterotrimers in...
G protein-coupled receptors (GPCRs) are efficient Guanine nucleotide exchange factors (GEFs) and exchange GDP to GTP on the Gα subunit of G protein heterotrimers in response to various extracellular stimuli, including neurotransmitters and light. GPCRs primarily broadcast signals through activated G proteins, GαGTP, and free Gβγ and are major disease drivers. Evidence shows that the ambient low threshold signaling required for cells is likely supplemented by signaling regulators such as non-GPCR GEFs and Guanine nucleotide Dissociation Inhibitors (GDIs). Activators of G protein Signaling 3 (AGS3) are recognized as a GDI involved in multiple health and disease-related processes. Nevertheless, understanding of AGS3 is limited, and no significant information is available on its structure-function relationship or signaling regulation in living cells. Here, we employed structure-guided engineering of a novel optogenetic GDI, based on the AGS3's G protein regulatory (GPR) motif, to understand its GDI activity and induce standalone Gβγ signaling in living cells on optical command. Our results demonstrate that plasma membrane recruitment of OptoGDI efficiently releases Gβγ, and its subcellular targeting generated localized PIP3 and triggered macrophage migration. Therefore, we propose OptoGDI as a powerful tool for optically dissecting GDI-mediated signaling pathways and triggering GPCR-independent Gβγ signaling in cells and .
PubMed: 38895415
DOI: 10.1101/2024.06.04.597473