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1.
Nat Commun ; 12(1): 5329, 2021 09 09.
Artigo em Inglês | MEDLINE | ID: mdl-34504078

RESUMO

Heterodimeric capping protein (CP/CapZ) is an essential factor for the assembly of branched actin networks, which push against cellular membranes to drive a large variety of cellular processes. Aside from terminating filament growth, CP potentiates the nucleation of actin filaments by the Arp2/3 complex in branched actin networks through an unclear mechanism. Here, we combine structural biology with in vitro reconstitution to demonstrate that CP not only terminates filament elongation, but indirectly stimulates the activity of Arp2/3 activating nucleation promoting factors (NPFs) by preventing their association to filament barbed ends. Key to this function is one of CP's C-terminal "tentacle" extensions, which sterically masks the main interaction site of the terminal actin protomer. Deletion of the ß tentacle only modestly impairs capping. However, in the context of a growing branched actin network, its removal potently inhibits nucleation promoting factors by tethering them to capped filament ends. End tethering of NPFs prevents their loading with actin monomers required for activation of the Arp2/3 complex and thus strongly inhibits branched network assembly both in cells and reconstituted motility assays. Our results mechanistically explain how CP couples two opposed processes-capping and nucleation-in branched actin network assembly.


Assuntos
Proteínas de Capeamento de Actina/metabolismo , Citoesqueleto de Actina/metabolismo , Complexo 2-3 de Proteínas Relacionadas à Actina/metabolismo , Actinas/metabolismo , Citoesqueleto/metabolismo , Melanócitos/metabolismo , Proteínas de Capeamento de Actina/química , Proteínas de Capeamento de Actina/genética , Citoesqueleto de Actina/ultraestrutura , Complexo 2-3 de Proteínas Relacionadas à Actina/química , Complexo 2-3 de Proteínas Relacionadas à Actina/genética , Actinas/química , Actinas/genética , Animais , Sítios de Ligação , Bovinos , Citoesqueleto/ultraestrutura , Gelsolina/química , Gelsolina/genética , Gelsolina/metabolismo , Regulação da Expressão Gênica , Humanos , Peptídeos e Proteínas de Sinalização Intercelular/química , Peptídeos e Proteínas de Sinalização Intercelular/genética , Peptídeos e Proteínas de Sinalização Intercelular/metabolismo , Cinética , Melanócitos/citologia , Melanoma Experimental/genética , Melanoma Experimental/metabolismo , Melanoma Experimental/patologia , Camundongos , Modelos Moleculares , Profilinas/química , Profilinas/genética , Profilinas/metabolismo , Ligação Proteica , Conformação Proteica em alfa-Hélice , Conformação Proteica em Folha beta , Domínios e Motivos de Interação entre Proteínas , Proteínas Recombinantes/química , Proteínas Recombinantes/genética , Proteínas Recombinantes/metabolismo , Timo/citologia , Timo/metabolismo , Proteína Neuronal da Síndrome de Wiskott-Aldrich/química , Proteína Neuronal da Síndrome de Wiskott-Aldrich/genética , Proteína Neuronal da Síndrome de Wiskott-Aldrich/metabolismo
2.
BMC Cancer ; 21(1): 981, 2021 Sep 01.
Artigo em Inglês | MEDLINE | ID: mdl-34470602

RESUMO

BACKGROUND: Paclitaxel (Taxol) is a microtubule-stabilizing drug used to treat several solid tumors, including ovarian, breast, non-small cell lung, and pancreatic cancers. The current treatment of ovarian cancer is chemotherapy using paclitaxel in combination with carboplatin as a frontline agent, and paclitaxel is also used in salvage treatment as a second line drug with a dose intensive regimen following recurrence. More recently, a dose dense approach for paclitaxel has been used to treat metastatic breast cancer with success. Paclitaxel binds to beta tubulin with high affinity and stabilizes microtubule bundles. As a consequence of targeting microtubules, paclitaxel kills cancer cells through inhibition of mitosis, causing mitotic catastrophes, and by additional, not yet well defined non-mitotic mechanism(s). RESULTS: In exploring methods to modulate activity of paclitaxel in causing cancer cell death, we unexpectedly found that a brief exposure of paclitaxel-treated cells in culture to low intensity ultrasound waves prevented the paclitaxel-induced cytotoxicity and death of the cancer cells. The treatment with ultrasound shock waves was found to transiently disrupt the microtubule cytoskeleton and to eliminate paclitaxel-induced rigid microtubule bundles. When cellular microtubules were labelled with a fluorescent paclitaxel analog, exposure to ultrasound waves led to the disassembly of the labeled microtubules and localization of the signals to perinuclear compartments, which were determined to be lysosomes. CONCLUSIONS: We suggest that ultrasound disrupts the paclitaxel-induced rigid microtubule cytoskeleton, generating paclitaxel bound fragments that undergo degradation. A new microtubule network forms from tubulins that are not bound by paclitaxel. Hence, ultrasound shock waves are able to abolish paclitaxel impact on microtubules. Thus, our results demonstrate that a brief exposure to low intensity ultrasound can reduce and/or eliminate cytotoxicity associated with paclitaxel treatment of cancer cells in cultures.


Assuntos
Neoplasias da Mama/patologia , Microtúbulos/patologia , Mitose , Neoplasias Ovarianas/patologia , Paclitaxel/farmacologia , Ondas Ultrassônicas , Antineoplásicos Fitogênicos/farmacologia , Apoptose , Neoplasias da Mama/tratamento farmacológico , Neoplasias da Mama/radioterapia , Proliferação de Células , Citoesqueleto/metabolismo , Feminino , Humanos , Microtúbulos/efeitos dos fármacos , Microtúbulos/efeitos da radiação , Neoplasias Ovarianas/tratamento farmacológico , Neoplasias Ovarianas/radioterapia , Tubulina (Proteína)/metabolismo , Células Tumorais Cultivadas
3.
Phys Rev Lett ; 127(10): 108101, 2021 Sep 03.
Artigo em Inglês | MEDLINE | ID: mdl-34533352

RESUMO

We investigate the rheological properties of interpenetrating networks reconstituted from the main cytoskeletal components: filamentous actin, microtubules, and vimentin intermediate filaments. The elastic modulus is determined largely by actin, with little contribution from either microtubules or vimentin. However, vimentin dramatically impacts the relaxation, with even small amounts significantly increasing the relaxation time of the interpenetrating network. This highly unusual decoupling between dissipation and elasticity may reflect weak attractive interactions between vimentin and actin networks.


Assuntos
Filamentos Intermediários/química , Modelos Químicos , Vimentina/química , Actinas/química , Actinas/metabolismo , Citoesqueleto/química , Citoesqueleto/metabolismo , Células Eucarióticas , Filamentos Intermediários/metabolismo , Microtúbulos/química , Microtúbulos/metabolismo , Reologia/métodos , Vimentina/metabolismo
4.
Int J Mol Sci ; 22(17)2021 Aug 26.
Artigo em Inglês | MEDLINE | ID: mdl-34502148

RESUMO

The effect of weightlessness on gametogenesis and the functional state of female germ cells are still poorly understood. We studied the ovaries of Drosophila melanogaster, the full development cycle of which (from zygote to sexually mature adults) passed under simulated microgravity by a random positioning machine. The rate of cellular respiration was studied by polarography as a parameter reflecting the functional state of mitochondria. The content of cytoskeletal proteins and histones was determined using Western blotting. The relative content of mRNA was determined using qRT-PCR. The results obtained indicated an increase in the rate of cellular respiration under simulated microgravity conditions during the full cycle of gametogenesis in Drosophila melanogaster due to complex I of the respiratory chain. In addition, an increase in the contents of actin cytoskeleton components was observed against the background of an increase in the mRNA content of the cytoskeleton's encoding genes. Moreover, we observed an increase in the relative content of histone H3 acetylated at Lys9 and Lys27, which may explain the increase in the expression of cytoskeletal genes. In conclusion, the formation of an adaptive pattern of functioning of the Drosophila melanogaster ovaries that developed under simulated microgravity includes structural and functional changes and epigenetic regulation.


Assuntos
Respiração Celular , Oogênese , Ovário/citologia , Simulação de Ausência de Peso , Animais , Citoesqueleto/metabolismo , Drosophila melanogaster , Complexo I de Transporte de Elétrons/genética , Complexo I de Transporte de Elétrons/metabolismo , Feminino , Histonas/metabolismo , Ovário/metabolismo , Óvulo/citologia , Óvulo/metabolismo , Transcriptoma
5.
Am J Physiol Regul Integr Comp Physiol ; 321(4): R572-R587, 2021 10 01.
Artigo em Inglês | MEDLINE | ID: mdl-34431403

RESUMO

Hyperoxic conditions are known to accelerate skeletal muscle regeneration after injuries. In the early phase of regeneration, macrophages invade the injured area and subsequently secrete various growth factors, which regulate myoblast proliferation and differentiation. Although hyperoxic conditions accelerate muscle regeneration, it is unknown whether this effect is indirectly mediated by macrophages. Here, using C2C12 cells, we show that not only hyperoxia but also hypoxia enhance myoblast proliferation directly, without accelerating differentiation into myotubes. Under hyperoxic conditions (95% O2 + 5% CO2), the cell membrane was damaged because of lipid oxidization, and a disrupted cytoskeletal structure, resulting in suppressed cell proliferation. However, a culture medium containing vitamin C (VC), an antioxidant, prevented this lipid oxidization and cytoskeletal disruption, resulting in enhanced proliferation in response to hyperoxia exposure of ≤4 h/day. In contrast, exposure to hypoxic conditions (95% N2 + 5% CO2) for ≤8 h/day enhanced cell proliferation. Hyperoxia did not promote cell differentiation into myotubes, regardless of whether the culture medium contained VC. Similarly, hypoxia did not accelerate cell differentiation. These results suggest that regardless of hyperoxia or hypoxia, changes in oxygen tension can enhance cell proliferation directly, but do not influence differentiation efficiency in C2C12 cells. Moreover, excess oxidative stress abrogated the enhancement of myoblast proliferation induced by hyperoxia. This research will contribute to basic data for applying the effects of hyperoxia or hypoxia to muscle regeneration therapy.


Assuntos
Diferenciação Celular , Proliferação de Células , Desenvolvimento Muscular , Mioblastos Esqueléticos/metabolismo , Estresse Oxidativo , Oxigênio/metabolismo , Regeneração , Animais , Antioxidantes/farmacologia , Ácido Ascórbico/farmacologia , Diferenciação Celular/efeitos dos fármacos , Hipóxia Celular , Linhagem Celular , Proliferação de Células/efeitos dos fármacos , Citoesqueleto/metabolismo , Citoesqueleto/patologia , Cinética , Metabolismo dos Lipídeos , Camundongos , Desenvolvimento Muscular/efeitos dos fármacos , Mioblastos Esqueléticos/efeitos dos fármacos , Mioblastos Esqueléticos/patologia , Estresse Oxidativo/efeitos dos fármacos , Oxigênio/toxicidade , Regeneração/efeitos dos fármacos
6.
Int J Mol Sci ; 22(16)2021 Aug 04.
Artigo em Inglês | MEDLINE | ID: mdl-34445080

RESUMO

This review extensively reports data from the literature concerning the complex relationships between the stress-induced c-Jun N-terminal kinases (JNKs) and the four main cytoskeleton elements, which are actin filaments, microtubules, intermediate filaments, and septins. To a lesser extent, we also focused on the two membrane-associated cytoskeletons spectrin and ESCRT-III. We gather the mechanisms controlling cytoskeleton-associated JNK activation and the known cytoskeleton-related substrates directly phosphorylated by JNK. We also point out specific locations of the JNK upstream regulators at cytoskeletal components. We finally compile available techniques and tools that could allow a better characterization of the interplay between the different types of cytoskeleton filaments upon JNK-mediated stress and during development. This overview may bring new important information for applied medical research.


Assuntos
Proteínas do Citoesqueleto/metabolismo , Citoesqueleto/metabolismo , Proteínas Quinases JNK Ativadas por Mitógeno/metabolismo , Citoesqueleto de Actina/metabolismo , Actinas/metabolismo , Animais , Complexos Endossomais de Distribuição Requeridos para Transporte/metabolismo , Humanos , Filamentos Intermediários/metabolismo , Microtúbulos/metabolismo , Septinas/metabolismo , Espectrina/metabolismo
7.
Int J Mol Sci ; 22(15)2021 Jul 28.
Artigo em Inglês | MEDLINE | ID: mdl-34360836

RESUMO

Lysyl oxidase-like 3 (LOXL3), belonging to the lysyl oxidase family, is responsible for the crosslinking in collagen or elastin. The cellular localization of LOXL3 is in the extracellular space by reason of its canonical function. In tumors, the presence of LOXL3 has been associated with genomic stability, cell proliferation, and metastasis. In silico analysis has shown that glioblastoma was among tumors with the highest LOXL3 expression levels. LOXL3 silencing of U87MG cells by siRNA led to the spreading of the tumor cell surface, and the transcriptome analysis of these cells revealed an upregulation of genes coding for extracellular matrix, cell adhesion, and cytoskeleton components, convergent to an increase in cell adhesion and a decrease in cell invasion observed in functional assays. Significant correlations of LOXL3 expression with genes coding for tubulins were observed in the mesenchymal subtype in the TCGA RNA-seq dataset of glioblastoma (GBM). Conversely, genes involved in endocytosis and lysosome formation, along with MAPK-binding proteins related to focal adhesion turnover, were downregulated, which may corroborate the observed decrease in cell viability and increase in the rate of cell death. Invasiveness is a major determinant of the recurrence and poor outcome of GBM patients, and downregulation of LOXL3 may contribute to halting the tumor cell invasion.


Assuntos
Aminoácido Oxirredutases/metabolismo , Adesão Celular , Regulação Neoplásica da Expressão Gênica , Glioblastoma/enzimologia , Aminoácido Oxirredutases/genética , Aminoácido Oxirredutases/fisiologia , Linhagem Celular Tumoral , Proliferação de Células , Simulação por Computador , Citoesqueleto/metabolismo , Endocitose , Matriz Extracelular/metabolismo , Perfilação da Expressão Gênica , Glioblastoma/genética , Glioblastoma/patologia , Glioblastoma/fisiopatologia , Humanos , Lisossomos/fisiologia , Invasividade Neoplásica
8.
Int J Mol Sci ; 22(15)2021 Jul 28.
Artigo em Inglês | MEDLINE | ID: mdl-34360857

RESUMO

Herein, for the first time, the potential relationships between the cytoskeleton-associated proteins DAAM1 and PREP with different testicular disorders, such as classic seminoma (CS), Leydig cell tumor (LCT), and Sertoli cell-only syndrome (SOS), were evaluated. Six CS, two LCT, and two SOS tissue samples were obtained during inguinal exploration in patients with a suspect testis tumor based on clinical examination and ultrasonography. DAAM1 and PREP protein levels and immunofluorescent localization were analyzed. An increased DAAM1 protein level in CS and SOS as compared to non-pathological (NP) tissue was observed, while LCT showed no significant differences. Conversely, PREP protein level increased in LCT, while it decreased in CS and SOS compared to NP tissue. These results were strongly supported by the immunofluorescence staining, revealing an altered localization and signal intensity of DAAM1 and PREP in the analyzed samples, highlighting a perturbed cytoarchitecture. Interestingly, in LCT spermatogonia, a specific DAAM1 nuclear localization was found, probably due to an enhanced testosterone production, as confirmed by the increased protein levels of steroidogenic enzymes. Finally, although further studies are needed to verify the involvement of other formins and microtubule-associated proteins, this report raised the opportunity to indicate DAAM1 and PREP as new potential markers, supporting the cytoskeleton dynamics changes occurring during normal and/or pathological cell differentiation.


Assuntos
Proteínas dos Microfilamentos/metabolismo , Proteínas Mitocondriais/metabolismo , Seminoma/metabolismo , Serina Endopeptidases/metabolismo , Neoplasias Testiculares/metabolismo , Proteínas rho de Ligação ao GTP/metabolismo , Biomarcadores Tumorais/metabolismo , Citoesqueleto/metabolismo , Humanos , Masculino , Espermatogônias/metabolismo
9.
Nat Chem Biol ; 17(9): 998-1007, 2021 09.
Artigo em Inglês | MEDLINE | ID: mdl-34341589

RESUMO

Subcellular compartmentalization of macromolecules increases flux and prevents inhibitory interactions to control biochemical reactions. Inspired by this functionality, we sought to build designer compartments that function as hubs to regulate the flow of information through cellular control systems. We report a synthetic membraneless organelle platform to control endogenous cellular activities through sequestration and insulation of native proteins. We engineer and express a disordered protein scaffold to assemble micron-size condensates and recruit endogenous clients via genomic tagging with high-affinity dimerization motifs. By relocalizing up to 90% of targeted enzymes to synthetic condensates, we efficiently control cellular behaviors, including proliferation, division and cytoskeletal organization. Further, we demonstrate multiple strategies for controlled cargo release from condensates to switch cells between functional states. These synthetic organelles offer a powerful and generalizable approach to modularly control cell decision-making in a variety of model systems with broad applications for cellular engineering.


Assuntos
Engenharia Celular , Organelas/metabolismo , Divisão Celular , Linhagem Celular Tumoral , Proliferação de Células , Citoesqueleto/metabolismo , Humanos , Organelas/química
10.
Nat Commun ; 12(1): 4900, 2021 08 12.
Artigo em Inglês | MEDLINE | ID: mdl-34385433

RESUMO

Skeletal muscle subsarcolemmal mitochondria (SSM) and intermyofibrillar mitochondria subpopulations have distinct metabolic activity and sensitivity, though the mechanisms that localize SSM to peripheral areas of muscle fibers are poorly understood. A protein interaction study and complexome profiling identifies PERM1 interacts with the MICOS-MIB complex. Ablation of Perm1 in mice reduces muscle force, decreases mitochondrial membrane potential and complex I activity, and reduces the numbers of SSM in skeletal muscle. We demonstrate PERM1 interacts with the intracellular adaptor protein ankyrin B (ANKB) that connects the cytoskeleton to the plasma membrane. Moreover, we identify a C-terminal transmembrane helix that anchors PERM1 into the outer mitochondrial membrane. We conclude PERM1 functions in the MICOS-MIB complex and acts as an adapter to connect the mitochondria with the sarcolemma via ANKB.


Assuntos
Anquirinas/metabolismo , Mitocôndrias Musculares/metabolismo , Complexos Multiproteicos/metabolismo , Proteínas Musculares/metabolismo , Sarcolema/metabolismo , Animais , Membrana Celular/metabolismo , Citoesqueleto/metabolismo , Potencial da Membrana Mitocondrial/genética , Potencial da Membrana Mitocondrial/fisiologia , Camundongos Knockout , Proteínas Mitocondriais/metabolismo , Proteínas Musculares/genética , Músculo Esquelético/metabolismo , Músculo Esquelético/fisiologia
11.
Nat Commun ; 12(1): 4969, 2021 08 17.
Artigo em Inglês | MEDLINE | ID: mdl-34404787

RESUMO

Multimeric cytoskeletal protein complexes orchestrate normal cellular function. However, protein-complex distributions in stressed, heterogeneous cell populations remain unknown. Cell staining and proximity-based methods have limited selectivity and/or sensitivity for endogenous multimeric protein-complex quantification from single cells. We introduce micro-arrayed, differential detergent fractionation to simultaneously detect protein complexes in hundreds of individual cells. Fractionation occurs by 60 s size-exclusion electrophoresis with protein complex-stabilizing buffer that minimizes depolymerization. Proteins are measured with a ~5-hour immunoassay. Co-detection of cytoskeletal protein complexes in U2OS cells treated with filamentous actin (F-actin) destabilizing Latrunculin A detects a unique subpopulation (~2%) exhibiting downregulated F-actin, but upregulated microtubules. Thus, some cells may upregulate other cytoskeletal complexes to counteract the stress of Latrunculin A treatment. We also sought to understand the effect of non-chemical stress on cellular heterogeneity of F-actin. We find heat shock may dysregulate filamentous and globular actin correlation. In this work, our assay overcomes selectivity limitations to biochemically quantify single-cell protein complexes perturbed with diverse stimuli.


Assuntos
Proteínas do Citoesqueleto/genética , Proteínas do Citoesqueleto/metabolismo , Citoesqueleto/metabolismo , Heterogeneidade Genética , Actinas/genética , Actinas/metabolismo , Animais , Compostos Bicíclicos Heterocíclicos com Pontes/farmacologia , Diferenciação Celular , Linhagem Celular , Resposta ao Choque Térmico , Humanos , Microtúbulos/metabolismo , Modelos Biológicos , Análise de Célula Única/métodos , Tiazolidinas/farmacologia
12.
Genes (Basel) ; 12(6)2021 06 16.
Artigo em Inglês | MEDLINE | ID: mdl-34208743

RESUMO

Adolescent idiopathic scoliosis (AIS) is a lateral spinal curvature >10° with rotation that affects 2-3% of healthy children across populations. AIS is known to have a significant genetic component, and despite a handful of risk loci identified in unrelated individuals by GWAS and next-generation sequencing methods, the underlying etiology of the condition remains largely unknown. In this study, we performed exome sequencing of affected individuals within 23 multigenerational families, with the hypothesis that the occurrence of rare, low frequency, disease-causing variants will co-occur in distantly related, affected individuals. Bioinformatic filtering of uncommon, potentially damaging variants shared by all sequenced family members revealed 1448 variants in 1160 genes across the 23 families, with 132 genes shared by two or more families. Ten genes were shared by >4 families, and no genes were shared by all. Gene enrichment analysis showed an enrichment of variants in cytoskeletal and extracellular matrix related processes. These data support a model that AIS is a highly polygenic disease, with few variant-containing genes shared between affected individuals across different family lineages. This work presents a novel resource for further exploration in familial AIS genetic research.


Assuntos
Citoesqueleto/genética , Herança Multifatorial , Polimorfismo Genético , Escoliose/genética , Citoesqueleto/metabolismo , Matriz Extracelular/genética , Matriz Extracelular/metabolismo , Humanos , Linhagem , Locos de Características Quantitativas , Escoliose/metabolismo , Sequenciamento Completo do Exoma
13.
Elife ; 102021 07 20.
Artigo em Inglês | MEDLINE | ID: mdl-34282727

RESUMO

Fission yeast cells maintain a rod shape due to conserved signaling pathways that organize the cytoskeleton for polarized growth. We discovered a mechanism linking the conserved protein kinase Pak1 with cell shape through the RNA-binding protein Sts5. Pak1 (also called Shk1 and Orb2) prevents Sts5 association with P bodies by directly phosphorylating its intrinsically disordered region (IDR). Pak1 and the cell polarity kinase Orb6 both phosphorylate the Sts5 IDR but at distinct residues. Mutations preventing phosphorylation in the Sts5 IDR cause increased P body formation and defects in cell shape and polarity. Unexpectedly, when cells encounter glucose starvation, PKA signaling triggers Pak1 recruitment to stress granules with Sts5. Through retargeting experiments, we reveal that Pak1 localizes to stress granules to promote rapid dissolution of Sts5 upon glucose addition. Our work reveals a new role for Pak1 in regulating cell shape through ribonucleoprotein granules during normal and stressed growth conditions.


Assuntos
Proteínas de Ciclo Celular/metabolismo , Forma Celular/fisiologia , Proteínas Serina-Treonina Quinases/metabolismo , Ribonucleoproteínas/metabolismo , Proteínas de Schizosaccharomyces pombe/metabolismo , Quinases Ativadas por p21/metabolismo , Polaridade Celular/fisiologia , Citoesqueleto/metabolismo , Fosforilação , Schizosaccharomyces/genética , Schizosaccharomyces/crescimento & desenvolvimento , Schizosaccharomyces/metabolismo , Transdução de Sinais
14.
Chem Commun (Camb) ; 57(62): 7597-7609, 2021 Aug 03.
Artigo em Inglês | MEDLINE | ID: mdl-34278403

RESUMO

How modern enzymes evolved as complex catalytic machineries to facilitate diverse chemical transformations is an open question for the emerging field of systems chemistry. Inspired by Nature's ingenuity in creating complex catalytic structures for exotic functions, short peptide-based cross ß amyloid sequences have been shown to access intricate binding surfaces demonstrating the traits of extant enzymes and proteins. Based on their catalytic proficiencies reported recently, these amyloid assemblies have been argued as the earliest protein folds. Herein, we map out the recent progress made by our laboratory and other research groups that demonstrate the catalytic diversity of cross ß amyloid assemblies. The important role of morphology and specific mutations in peptide sequences has been underpinned in this review. We have divided the feature article into different sections where examples from biology have been covered demonstrating the mechanism of extant biocatalysts and compared with recent works on cross ß amyloid folds showing covalent catalysis, aldolase, hydrolase, peroxidase-like activities and complex cascade catalysis. Beyond equilibrium, we have extended our discussion towards transient catalytic amyloid phases mimicking the energy driven cytoskeleton polymerization. Finally, a future outlook has been provided on the way ahead for short peptide-based systems chemistry approaches that can lead to the development of robust catalytic networks with improved enzyme-like proficiencies and higher complexities. The discussed examples along with the rationale behind selecting specific amino acids sequence will benefit readers to design systems for achieving catalytic reactivity similar to natural complex enzymes.


Assuntos
Peptídeos beta-Amiloides/química , Peptídeos beta-Amiloides/metabolismo , Biocatálise , Citoesqueleto/metabolismo , Multimerização Proteica , Estrutura Quaternária de Proteína
15.
Development ; 148(15)2021 08 01.
Artigo em Inglês | MEDLINE | ID: mdl-34323270

RESUMO

The formation of the cardiac tube is a remarkable example of complex morphogenetic processes conserved from invertebrates to humans. It involves coordinated collective migration of contralateral rows of cardiac cells. The molecular processes underlying the specification of cardioblasts (CBs) prior to migration are well established and significant advances have been made in understanding the process of lumen formation. However, the mechanisms of collective cardiac cells migration remain elusive. Here, we have identified CAP and MSP300 as novel actors involved during CB migration. They both exhibit highly similar temporal and spatial expression patterns in Drosophila migrating cardiac cells, and are necessary for the correct number and alignment of CBs, a prerequisite for the coordination of their collective migration. Our data suggest that CAP and MSP300 are part of a protein complex linking focal adhesion sites to nuclei via the actin cytoskeleton that maintains post-mitotic state and correct alignment of CBs.


Assuntos
Núcleo Celular/metabolismo , Citoesqueleto/metabolismo , Proteínas de Drosophila/metabolismo , Drosophila/metabolismo , Coração/fisiologia , Miocárdio/metabolismo , Organogênese/fisiologia , Animais , Movimento Celular/fisiologia , Regulação da Expressão Gênica no Desenvolvimento/fisiologia , Proteínas do Tecido Nervoso/metabolismo , Transdução de Sinais/fisiologia
16.
Development ; 148(14)2021 07 15.
Artigo em Inglês | MEDLINE | ID: mdl-34228789

RESUMO

Sound transduction occurs in the hair bundle, the apical compartment of sensory hair cells in the inner ear. The hair bundle is formed of actin-based stereocilia aligned in rows of graded heights. It was previously shown that the GNAI-GPSM2 complex is part of a developmental blueprint that defines the polarized organization of the apical cytoskeleton in hair cells, including stereocilia distribution and elongation. Here, we report a role for multiple PDZ domain (MPDZ) protein during apical hair cell morphogenesis in mouse. We show that MPDZ is enriched at the hair cell apical membrane along with MAGUK p55 subfamily member 5 (MPP5/PALS1) and the Crumbs protein CRB3. MPDZ is required there to maintain the proper segregation of apical blueprint proteins, including GNAI-GPSM2. Loss of the blueprint coincides with misaligned stereocilia placement in Mpdz mutant hair cells, and results in permanently misshapen hair bundles. Graded molecular and structural defects along the cochlea can explain the profile of hearing loss in Mpdz mutants, where deficits are most severe at high frequencies.


Assuntos
Citoesqueleto/metabolismo , Células Ciliadas Auditivas/metabolismo , Domínios PDZ , Actinas/metabolismo , Animais , Cóclea/metabolismo , Orelha Interna/metabolismo , Perda Auditiva/metabolismo , Proteínas de Membrana , Camundongos , Estereocílios/metabolismo
17.
J Plant Physiol ; 264: 153473, 2021 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-34298331

RESUMO

Plant endoplasmic reticulum (ER) remodelling is likely to be important for its function in targeted protein secretion, organelle interaction and signal exchange. It has been known for decades that the structure and movement of the ER network is mainly regulated by the actin cytoskeleton through actin motor proteins and membrane-cytoskeleton adaptors. Recent discoveries also revealed alternative pathways that influence ER movement, through a microtubule-based machinery. Therefore, plants utilize both cytoskeletal components to drive ER dynamics, a process that is likely to be dependent on the cell type and the developmental stages. On the other hand, the ER membrane also has a direct effect towards the organization of the cytoskeletal network and disrupting the tethering factors at the ER-PM interface also rearranges the cytoskeletal structure. However, the influence of the ER network on the cytoskeleton organization has not been studied. In this review, we will provide an overview of the ER-cytoskeleton network in plants, and discuss the most recent discoveries in the field.


Assuntos
Citoesqueleto/metabolismo , Retículo Endoplasmático/metabolismo , Plantas/metabolismo , Proteínas de Plantas/metabolismo
18.
Int J Mol Sci ; 22(14)2021 Jul 19.
Artigo em Inglês | MEDLINE | ID: mdl-34299330

RESUMO

The ability of endocannabinoid (eCB) to change functional microglial phenotype can be explored as a possible target for therapeutic intervention. Since the inhibition of fatty acid amide hydrolase (FAAH), the main catabolic enzyme of anandamide (AEA), may provide beneficial effects in mice model of Alzheimer's disease (AD)-like pathology, we aimed at determining whether the FAAH inhibitor URB597 might target microglia polarization and alter the cytoskeleton reorganization induced by the amyloid-ß peptide (Aß). The morphological evaluation showed that Aß treatment increased the surface area of BV-2 cells, which acquired a flat and polygonal morphology. URB597 treatment partially rescued the control phenotype of BV-2 cells when co-incubated with Aß. Moreover, URB597 reduced both the increase of Rho protein activation in Aß-treated BV-2 cells and the Aß-induced migration of BV-2 cells, while an increase of Cdc42 protein activation was observed in all samples. URB597 also increased the number of BV-2 cells involved in phagocytosis. URB597 treatment induced the polarization of microglial cells towards an anti-inflammatory phenotype, as demonstrated by the decreased expression of iNOS and pro-inflammatory cytokines along with the parallel increase of Arg-1 and anti-inflammatory cytokines. Taken together, these data suggest that FAAH inhibition promotes cytoskeleton reorganization, regulates phagocytosis and cell migration processes, thus driving microglial polarization towards an anti-inflammatory phenotype.


Assuntos
Amidoidrolases/antagonistas & inibidores , Benzamidas/farmacologia , Carbamatos/farmacologia , Microglia/efeitos dos fármacos , Microglia/metabolismo , Doença de Alzheimer/metabolismo , Doença de Alzheimer/patologia , Amidoidrolases/metabolismo , Peptídeos beta-Amiloides/metabolismo , Peptídeos beta-Amiloides/farmacologia , Animais , Ácidos Araquidônicos/metabolismo , Linhagem Celular , Movimento Celular/fisiologia , Polaridade Celular/fisiologia , Citocinas/metabolismo , Citoesqueleto/metabolismo , Modelos Animais de Doenças , Endocanabinoides/metabolismo , Camundongos , Microglia/patologia , Alcamidas Poli-Insaturadas/metabolismo
19.
BMC Genomics ; 22(1): 570, 2021 Jul 24.
Artigo em Inglês | MEDLINE | ID: mdl-34303338

RESUMO

BACKGROUND: Formin, a highly conserved multi-domain protein, interacts with microfilaments and microtubules. Although specifically expressed formin genes in anthers are potentially significant in research on male sterility and hybrid wheat breeding, similar reports in wheat, especially in thermo-sensitive genic male sterile (TGMS) wheat, remain elusive. RESULTS: Herein, we systematically characterized the formin genes in TGMS wheat line BS366 named TaFormins (TaFHs) and predicted their functions in inducing stress response. In total, 25 TaFH genes were uncovered, majorly localized in 2A, 2B, and 2D chromosomes. According to the neighbor-joining (NJ) method, all TaFH proteins from wheat and other plants clustered in 6 sub-groups (A-F). The modeled 3D structures of TaFH1-A/B, TaFH2-A/B, TaFH3-A/B and TaFH3-B/D were validated. And different numbers of stress and hormone-responsive regulatory elements in their 1500 base pair promoter regions were contained in the TaFH genes copies. TaFHs had specific temporal and spatial expression characteristics, whereby TaFH1, TaFH4, and TaFH5 were expressed highly in the stamen of BS366. Besides, the accumulation of TaFHs was remarkably lower in a low-temperature sterile condition (Nanyang) than fertile condition (Beijing), particularly at the early stamen development stage. The pollen cytoskeleton of BS366 was abnormal in the three stages under sterile and fertile environments. Furthermore, under different stress levels, TaFHs expression could be induced by drought, salt, abscisic acid (ABA), salicylic acid (SA), methyl jasmonate (MeJA), indole-3-acetic acid (IAA), polyethylene glycol (PEG), and low temperature. Some miRNAs, including miR167, miR1120, and miR172, interacts with TaFH genes; thus, we constructed an interaction network between microRNAs, TaFHs, phytohormone responses, and distribution of cytoskeleton to reveal the regulatory association between upstream genes of TaFH family members and sterile. CONCLUSIONS: Collectively, this comprehensive analysis provides novel insights into TaFHs and miRNA resources for wheat breeding. These findings are, therefore, valuable in understanding the mechanism of TGMS fertility conversion in wheat.


Assuntos
Melhoramento Vegetal , Triticum , Citoesqueleto/metabolismo , Fertilidade/genética , Forminas , Regulação da Expressão Gênica de Plantas , Microtúbulos/metabolismo , Proteínas de Plantas/genética , Proteínas de Plantas/metabolismo , Pólen/genética , Pólen/metabolismo , Triticum/genética , Triticum/metabolismo
20.
Int J Mol Sci ; 22(11)2021 Jun 07.
Artigo em Inglês | MEDLINE | ID: mdl-34200503

RESUMO

The interaction of tumor cells with blood vessels is one of the key steps during cancer metastasis. Metastatic cancer cells exhibit phenotypic state changes during this interaction: (1) they form tunneling nanotubes (TNTs) with endothelial cells, which act as a conduit for intercellular communication; and (2) metastatic cancer cells change in order to acquire an elongated phenotype, instead of the classical cellular aggregates or mammosphere-like structures, which it forms in three-dimensional cultures. Here, we demonstrate mechanistically that a siRNA-based knockdown of the exocyst complex protein Sec3 inhibits TNT formation. Furthermore, a set of pharmacological inhibitors for Rho GTPase-exocyst complex-mediated cytoskeletal remodeling is introduced, which inhibits TNT formation, and induces the reversal of the more invasive phenotype of cancer cell (spindle-like) into a less invasive phenotype (cellular aggregates or mammosphere). Our results offer mechanistic insights into this nanoscale communication and shift of phenotypic state during cancer-endothelial interactions.


Assuntos
Neoplasias da Mama/patologia , Comunicação Celular , Endotélio Vascular/patologia , Nanotubos/química , Proteínas de Transporte Vesicular/metabolismo , Proteínas rho de Ligação ao GTP/metabolismo , Técnicas de Cultura de Células , Citoplasma/metabolismo , Citoesqueleto/metabolismo , Feminino , Humanos , Metástase Neoplásica , Fenótipo , Células Tumorais Cultivadas , Proteínas de Transporte Vesicular/genética , Proteínas rho de Ligação ao GTP/genética
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