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Cell Reports Jun 2024Motor proteins transport diverse membrane-bound vesicles along microtubules inside cells. How specific lipids, particularly rare lipids, on the membrane recruit and...
Motor proteins transport diverse membrane-bound vesicles along microtubules inside cells. How specific lipids, particularly rare lipids, on the membrane recruit and activate motors is poorly understood. To address this, we prepare spherical supported lipid bilayers (SSLBs) consisting of a latex bead enclosed within a membrane of desired lipid composition. SSLBs containing phosphatidic acid recruit dynein when incubated with Dictyostelium fractions but kinesin-1 when incubated with rat brain fractions. These SSLBs allow controlled biophysical investigation of membrane-bound motors along with their regulators at the single-cargo level in vitro. Optical trapping of single SSLBs reveals that motor-specific inhibitors can "lock" a motor to a microtubule, explaining the paradoxical arrest of overall cargo transport by such inhibitors. Increasing their size causes SSLBs to reverse direction more frequently, relevant to how large cargoes may navigate inside cells. These studies are relevant to understand how unidirectional or bidirectional motion of vesicles might be generated.
Topics: Lipid Bilayers; Phosphatidic Acids; Microtubules; Animals; Dictyostelium; Rats; Kinesins; Dyneins
PubMed: 38771696
DOI: 10.1016/j.celrep.2024.114252 -
Scientific Reports May 2024The patterns of Formin B and of the Arp2/3 complex formed during mitosis were studied in a mutant of Dictyostelium discoideum that produces multinucleate cells, which...
The patterns of Formin B and of the Arp2/3 complex formed during mitosis were studied in a mutant of Dictyostelium discoideum that produces multinucleate cells, which divide by the ingression of unilateral cleavage furrows. During cytokinesis the cells of this mutant remain spread on a glass surface where they generate a planar pattern based on the sorting-out of actin-binding proteins. During anaphase, Formin B and Arp2/3 became localized to the regions of microtubule asters around the centrosomes; Formin B in particular in the form of round, quite uniformly covered areas. These areas have been shown to be depleted of myosin II and the actin-filament crosslinker cortexillin, and to be avoided by cleavage furrows on their path into the cell.
Topics: Microtubules; Dictyostelium; Mitosis; Microfilament Proteins; Actin-Related Protein 2-3 Complex; Protozoan Proteins; Protein Transport; Cytokinesis; Actins
PubMed: 38755233
DOI: 10.1038/s41598-024-61967-7 -
Nature Communications May 2024Greenbeard genetic elements encode rare perceptible signals, signal recognition ability, and altruism towards others that display the same signal. Putative greenbeards...
Greenbeard genetic elements encode rare perceptible signals, signal recognition ability, and altruism towards others that display the same signal. Putative greenbeards have been described in various organisms but direct evidence for all the properties in one system is scarce. The tgrB1-tgrC1 allorecognition system of Dictyostelium discoideum encodes two polymorphic membrane proteins which protect cells from chimerism-associated perils. During development, TgrC1 functions as a ligand-signal and TgrB1 as its receptor, but evidence for altruism has been indirect. Here, we show that mixing wild-type and activated tgrB1 cells increases wild-type spore production and relegates the mutants to the altruistic stalk, whereas mixing wild-type and tgrB1-null cells increases mutant spore production and wild-type stalk production. The tgrB1-null cells cheat only on partners that carry the same tgrC1-allotype. Therefore, TgrB1 activation confers altruism whereas TgrB1 inactivation causes allotype-specific cheating, supporting the greenbeard concept and providing insight into the relationship between allorecognition, altruism, and exploitation.
Topics: Altruism; Chemotaxis; Dictyostelium; Membrane Proteins; Mutation; Protozoan Proteins; Signal Transduction; Spores, Protozoan
PubMed: 38734736
DOI: 10.1038/s41467-024-48380-4 -
Molecules (Basel, Switzerland) May 2024Cellular slime molds are excellent model organisms in the field of cell and developmental biology because of their simple developmental patterns. During our studies on...
Cellular slime molds are excellent model organisms in the field of cell and developmental biology because of their simple developmental patterns. During our studies on the identification of bioactive molecules from secondary metabolites of cellular slime molds toward the development of novel pharmaceuticals, we revealed the structural diversity of secondary metabolites. Cellular slime molds grow by feeding on bacteria, such as and without using medium components. Although changing the feeding bacteria is expected to affect dramatically the secondary metabolite production, the effect of the feeding bacteria on the production of secondary metabolites is not known. Herein, we report the isolation and structure elucidation of clavapyrone () from , intermedipyrone () from , and magnumiol () from . These compounds are not obtained from usual cultural conditions with but obtained from coincubated conditions with spp. The results demonstrate the diversity of the secondary metabolites of cellular slime molds and suggest that widening the range of feeding bacteria for cellular slime molds would increase their application potential in drug discovery.
Topics: Dictyostelium; Pyrones; Pseudomonas; Molecular Structure; Secondary Metabolism
PubMed: 38731634
DOI: 10.3390/molecules29092143 -
Biochemical Pharmacology Jul 2024The spread of malarial parasites resistant to first-line treatments such as artemisinin combination therapies is a global health concern. Differentiation-inducing factor...
The spread of malarial parasites resistant to first-line treatments such as artemisinin combination therapies is a global health concern. Differentiation-inducing factor 1 (DIF-1) is a chlorinated alkylphenone (1-(3,5-dichloro-2,6-dihydroxy-4-methoxyphenyl) hexan-1-one) originally found in the cellular slime mould Dictyostelium discoideum. We previously showed that some derivatives of DIF-1, particularly DIF-1(+2) (1-(3,5-dichloro-2,6-dihydroxy-4-methoxyphenyl) octan-1-one), exert potent antimalarial activities. In this study, we synthesised DIF-1(+3) (1-(3,5-dichloro-2,6-dihydroxy-4-methoxyphenyl) nonan-1-one). We then evaluated the effects of DIF-1(+3) in vitro on Plasmodium falciparum and in vivo over 7 days (50-100 mg/kg/day) in a mouse model of Plasmodium berghei. DIF-1(+3) exhibited a half-maximal inhibitory concentration of approximately 20-30 % of DIF-1(+2) in three laboratory strains with a selectivity index > 263, including in strains resistant to chloroquine and artemisinin. Parasite growth and multiplication were almost completely suppressed by treatment with 100 mg/kg DIF-1(+3). The survival time of infected mice was significantly increased (P = 0.006) with no apparent adverse effects. In summary, addition of an acyl group to DIF-1(+2) to prepare DIF-1(+3) substantially enhanced antimalarial activity, even in drug-resistant malaria, indicating the potential of applying DIF-1(+3) for malaria treatment.
Topics: Antimalarials; Animals; Mice; Hexanones; Plasmodium falciparum; Plasmodium berghei; Malaria; Dictyostelium; Acylation; Female; Hydrocarbons, Chlorinated
PubMed: 38697310
DOI: 10.1016/j.bcp.2024.116243 -
Heliyon Apr 2024Alzheimer's disease (AD) is increasingly becoming a major public health concern in our society. While many studies have explored the use of natural polyketides,...
Alzheimer's disease (AD) is increasingly becoming a major public health concern in our society. While many studies have explored the use of natural polyketides, alkaloids, and other chemical components in AD treatment, there is an urgent need to clarify the concept of multi-target treatment for AD. This study focuses on using network pharmacology approach to elucidate how secondary metabolites from affect AD through multi-target or indirect mechanisms. The secondary metabolites produced by during their development were obtained from literature sources and PubChem. Disease targets were selected using GeneCards, DisGeNET, and CTD databases, while compound-based targets were identified through Swiss target prediction and Venn diagrams were used to find intersections between these targets. A network depicting the interplay among disease, drugs, active ingredients, and key target proteins (PPI network) was formed utilizing the STRING (Protein-Protein Interaction Networks Functional Enrichment Analysis) database. To anticipate the function and mechanism of the screened compounds, GO and KEGG enrichment analyses were conducted and visually presented using graphs and bubble charts. After the screening phase, the top interacting targets in the PPI network and the compound with the most active target were chosen for subsequent molecular docking and molecular dynamic simulation studies. This study identified nearly 50 potential targeting genes for each of the screened compounds and revealed multiple signaling pathways. Among these pathways, the inflammatory pathway stood out. COX-2, a receptor associated with neuroinflammation, showed differential expression in various stages of AD, particularly in pyramidal neurons during the early stages of the disease. This increase in COX-2 expression is likely induce by higher levels of IL-1, which is associated with neuritic plaques and microglial cells in AD. Molecular docking investigations demonstrated a strong binding interaction between the terpene compound PQA-11 and the neuroinflammatory receptor COX2, with a substantial binding affinity of -8.4 kcal/mol. Subsequently, a thorough analysis of the docked complex (COX2-PQA11) through Molecular Dynamics Simulation showed lower RMSD, minimal RMSF fluctuations, and a reduced total energy of -291.35 kJ/mol compared to the standard drug. These findings suggest that the therapeutic effect of PQA-11 operates through the inflammatory pathway, laying the groundwork for further in-depth research into the role of secondary metabolites in AD treatment.
PubMed: 38644825
DOI: 10.1016/j.heliyon.2024.e28852 -
Biochemical Society Transactions Apr 2024The maintenance of phosphate homeostasis serves as a foundation for energy metabolism and signal transduction processes in all living organisms. Inositol pyrophosphates... (Review)
Review
The maintenance of phosphate homeostasis serves as a foundation for energy metabolism and signal transduction processes in all living organisms. Inositol pyrophosphates (PP-InsPs), composed of an inositol ring decorated with monophosphate and diphosphate moieties, and inorganic polyphosphate (polyP), chains of orthophosphate residues linked by phosphoanhydride bonds, are energy-rich biomolecules that play critical roles in phosphate homeostasis. There is a complex interplay between these two phosphate-rich molecules, and they share an interdependent relationship with cellular adenosine triphosphate (ATP) and inorganic phosphate (Pi). In eukaryotes, the enzymes involved in PP-InsP synthesis show some degree of conservation across species, whereas distinct enzymology exists for polyP synthesis among different organisms. In fact, the mechanism of polyP synthesis in metazoans, including mammals, is still unclear. Early studies on PP-InsP and polyP synthesis were conducted in the slime mould Dictyostelium discoideum, but it is in the budding yeast Saccharomyces cerevisiae that a clear understanding of the interplay between polyP, PP-InsPs, and Pi homeostasis has now been established. Recent research has shed more light on the influence of PP-InsPs on polyP in mammals, and the regulation of both these molecules by cellular ATP and Pi levels. In this review we will discuss the cross-talk between PP-InsPs, polyP, ATP, and Pi in the context of budding yeast, slime mould, and mammals. We will also highlight the similarities and differences in the relationship between these phosphate-rich biomolecules among this group of organisms.
Topics: Polyphosphates; Animals; Inositol Phosphates; Homeostasis; Humans; Saccharomyces cerevisiae; Adenosine Triphosphate; Dictyostelium; Signal Transduction
PubMed: 38629621
DOI: 10.1042/BST20230256 -
Journal of Molecular Modeling Apr 2024Parkinson's disease is a neurodegenerative condition characterized by the degeneration of dopaminergic neurons, resulting in motor disabilities such as rigidity,...
CONTEXT
Parkinson's disease is a neurodegenerative condition characterized by the degeneration of dopaminergic neurons, resulting in motor disabilities such as rigidity, bradykinesia, postural instability, and resting tremors. While the exact cause of Parkinson's remains uncertain, both familial and sporadic forms are often associated with the G2019S mutation found in the kinase domain of LRRK2. Roco4 is an analogue of LRRK2 protein in Dictyostelium discoideum which is an established model organism to investigate LRRK2 inhibitors. In this study, the potential treatment of Parkinson's was explored by inhibiting the activity of the mutated LRRK2 protein using Roco4 as the base protein structure. Mongolicain-A and Bacoside-A exhibited significant selectivity towards the G2019S mutation, displaying a binding affinity of - 12.3 Kcal/mol and - 11.4 Kcal/mol respectively. Mongolicain-A demonstrated increased specificity towards Roco4, while Bacoside-A demonstrated significant binding affinity to all 34 kinases proteins alike. The Molecular Dynamics Studies (MDS) results strongly suggests that Mongolicain-A is a significant inhibitor of Roco4 kinase. ADMET and drugability analysis also suggests that among the two best ligands, Mongolicain-A demonstrates significant physicochemical properties to be suitable for best drug like molecule. Based on the in-silico molecular docking, molecular dynamic simulation, ADMET and drugability analyses, it is strongly suggested that, Mongolicain-A could be a potential candidate for treatment and management of Parkinson's disease via inhibition of LRRK2 protein. Further in-vitro and in-vivo investigations are in demand to validate these findings.
METHODS
To identify potential inhibitors, 3069 phytochemicals were screened using molecular docking via AutoDock Vina. Molecular Dynamics Simulation was carried out using GROMACS 2022.2 for a duration of 100ns per complex to study the stability and inhibition potential of the protein ligand complexes. ADMET analysis was carriedout using Molinspiration and preADMET web tool.
Topics: Humans; Parkinson Disease; Leucine-Rich Repeat Serine-Threonine Protein Kinase-2; Molecular Dynamics Simulation; Dictyostelium; Molecular Docking Simulation; Parkinsonian Disorders; Antineoplastic Agents
PubMed: 38625397
DOI: 10.1007/s00894-024-05925-0 -
Cells Mar 2024Autosomal dominant polycystic kidney disease (ADPKD) occurs when the proteins Polycystin-1 (PC1, ) and Polycystin-2 (PC2, ) contain mutations. PC1 is a large membrane...
Autosomal dominant polycystic kidney disease (ADPKD) occurs when the proteins Polycystin-1 (PC1, ) and Polycystin-2 (PC2, ) contain mutations. PC1 is a large membrane receptor that can interact and form a complex with the calcium-permeable cation channel PC2. This complex localizes to the plasma membrane, primary cilia and ER. Dysregulated calcium signalling and consequential alterations in downstream signalling pathways in ADPKD are linked to cyst formation and expansion; however, it is not completely understood how PC1 and PC2 regulate calcium signalling. We have studied Polycystin-2 mediated calcium signalling in the model organism by overexpressing and knocking down the expression of the endogenous Polycystin-2 homologue, Polycystin-2. Chemoattractant-stimulated cytosolic calcium response magnitudes increased and decreased in overexpression and knockdown strains, respectively, and analysis of the response kinetics indicates that Polycystin-2 is a significant contributor to the control of Ca responses. Furthermore, basal cytosolic calcium levels were reduced in Polycystin-2 knockdown transformants. These alterations in Ca signalling also impacted other downstream Ca-sensitive processes including growth rates, endocytosis, stalk cell differentiation and spore viability, indicating that is a useful model to study Polycystin-2 mediated calcium signalling.
Topics: Humans; Polycystic Kidney, Autosomal Dominant; Dictyostelium; TRPP Cation Channels; Calcium; Calcium Signaling; Calcium Channels
PubMed: 38607049
DOI: 10.3390/cells13070610 -
PeerJ 2024Cooperation is widespread across life, but its existence can be threatened by exploitation. The rise of obligate social cheaters that are incapable of contributing to a...
Cooperation is widespread across life, but its existence can be threatened by exploitation. The rise of obligate social cheaters that are incapable of contributing to a necessary cooperative function can lead to the loss of that function. In the social amoeba , obligate social cheaters cannot form dead stalk cells and in chimeras instead form living spore cells. This gives them a competitive advantage within chimeras. However, obligate cheaters of this kind have thus far not been found in nature, probably because they are often enough in clonal populations that they need to retain the ability to produce stalks. In this study we discovered an additional cost to obligate cheaters. Even when there are wild-type cells to parasitize, the chimeric fruiting bodies that result have shorter stalks and these are disadvantaged in spore dispersal. The inability of obligate cheaters to form fruiting bodies when they are on their own combined with the lower functionality of fruiting bodies when they are not represent limits on obligate social cheating as a strategy.
Topics: Dictyostelium; Amoeba; Reproduction; Spores, Protozoan
PubMed: 38562996
DOI: 10.7717/peerj.17118