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1.
Nat Commun ; 12(1): 84, 2021 01 04.
Artigo em Inglês | MEDLINE | ID: mdl-33398012

RESUMO

The disruption in blood supply due to myocardial infarction is a critical determinant for infarct size and subsequent deterioration in function. The identification of factors that enhance cardiac repair by the restoration of the vascular network is, therefore, of great significance. Here, we show that the transcription factor Zinc finger E-box-binding homeobox 2 (ZEB2) is increased in stressed cardiomyocytes and induces a cardioprotective cross-talk between cardiomyocytes and endothelial cells to enhance angiogenesis after ischemia. Single-cell sequencing indicates ZEB2 to be enriched in injured cardiomyocytes. Cardiomyocyte-specific deletion of ZEB2 results in impaired cardiac contractility and infarct healing post-myocardial infarction (post-MI), while cardiomyocyte-specific ZEB2 overexpression improves cardiomyocyte survival and cardiac function. We identified Thymosin ß4 (TMSB4) and Prothymosin α (PTMA) as main paracrine factors released from cardiomyocytes to stimulate angiogenesis by enhancing endothelial cell migration, and whose regulation is validated in our in vivo models. Therapeutic delivery of ZEB2 to cardiomyocytes in the infarcted heart induces the expression of TMSB4 and PTMA, which enhances angiogenesis and prevents cardiac dysfunction. These findings reveal ZEB2 as a beneficial factor during ischemic injury, which may hold promise for the identification of new therapies.


Assuntos
Isquemia/patologia , Miócitos Cardíacos/metabolismo , Neovascularização Fisiológica , Homeobox 2 de Ligação a E-box com Dedos de Zinco/metabolismo , Animais , Movimento Celular/genética , Proliferação de Células/genética , Dependovirus/metabolismo , Regulação da Expressão Gênica , Humanos , Isquemia/genética , Camundongos Knockout , Modelos Biológicos , Infarto do Miocárdio/genética , Infarto do Miocárdio/patologia , Miócitos Cardíacos/patologia , Neovascularização Fisiológica/genética , Precursores de Proteínas/genética , Precursores de Proteínas/metabolismo , RNA Mensageiro/genética , RNA Mensageiro/metabolismo , Timosina/análogos & derivados , Timosina/genética , Timosina/metabolismo , Homeobox 2 de Ligação a E-box com Dedos de Zinco/genética
2.
Nat Commun ; 11(1): 5736, 2020 11 12.
Artigo em Inglês | MEDLINE | ID: mdl-33184256

RESUMO

Highly charged intrinsically disordered proteins can form complexes with very high affinity in which both binding partners fully retain their disorder and dynamics, exemplified by the positively charged linker histone H1.0 and its chaperone, the negatively charged prothymosin α. Their interaction exhibits another surprising feature: The association/dissociation kinetics switch from slow two-state-like exchange at low protein concentrations to fast exchange at higher, physiologically relevant concentrations. Here we show that this change in mechanism can be explained by the formation of transient ternary complexes favored at high protein concentrations that accelerate the exchange between bound and unbound populations by orders of magnitude. Molecular simulations show how the extreme disorder in such polyelectrolyte complexes facilitates (i) diffusion-limited binding, (ii) transient ternary complex formation, and (iii) fast exchange of monomers by competitive substitution, which together enable rapid kinetics. Biological polyelectrolytes thus have the potential to keep regulatory networks highly responsive even for interactions with extremely high affinities.


Assuntos
Proteínas Intrinsicamente Desordenadas/química , Polieletrólitos/química , Cinética , Espectroscopia de Ressonância Magnética , Chaperonas Moleculares/química , Simulação de Dinâmica Molecular , Ligação Proteica , Domínios e Motivos de Interação entre Proteínas , Precursores de Proteínas/química , Coloração e Rotulagem , Timosina/análogos & derivados
4.
Food Chem ; 327: 127002, 2020 Oct 15.
Artigo em Inglês | MEDLINE | ID: mdl-32438262

RESUMO

This study was designed to investigate proteome changes in Japanese puffer fish (Takifugu rubripes) during short- and long-term frozen storage. In total, 1484 proteins were quantified, and 164 proteins were identified as differential abundance proteins (DAPs) in Japanese puffer fish from two frozen storage treatment groups (14 days and 60 days) compared with the fresh control group. Correlation analysis between the DAPs and quality traits of the puffer fish muscle showed that 106 proteins were correlated closely with colour and texture (hardness, elasticity, and chewiness). Bioinformatics analysis revealed and Western blot analysis verified that Putative prothymosin alpha species, Bridging integrator 3, NADH: the ubiquinone oxidoreductase subunit and Mx species are candidate biomarkers for puffer fish properties. This study offers valuable evidence to improve the quality control and monitoring of Japanese puffer fish during transportation and storage.


Assuntos
Biomarcadores/análise , Produtos Pesqueiros/análise , Proteínas de Peixes/análise , Takifugu , Animais , Cor , Biologia Computacional/métodos , Análise de Alimentos/métodos , Qualidade dos Alimentos , Armazenamento de Alimentos , Congelamento , Músculo Esquelético/química , Precursores de Proteínas/análise , Timosina/análogos & derivados , Timosina/análise
5.
J Pharmacol Sci ; 143(2): 127-131, 2020 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-32156464

RESUMO

The inhibition of retinal ischemia-induced damage by post-ischemic prothymosin alpha (ProTα) was not affected in toll-like receptor 4 knockout (TLR4-/-) mice but blocked by the pretreatment with antibody against F0/F1 ATPase α- or ß-subunit, novel candidate for ProTα-receptor. In addition to the previous observation of ProTα-induced ATP release from cells, the present study showed a ProTα-induced enhancement of ATP hydrolysis activity of recombinant ATP5A1/5B complex. As the protection of retinal function by post-ischemic ProTα was abolished by anti-P2Y12 antibody, the activation of F0/F1 ATPase and subsequent P2Y12 receptor system may play roles in beneficial actions by post-ischemic ProTα.


Assuntos
Isquemia/metabolismo , Isquemia/prevenção & controle , Precursores de Proteínas/administração & dosagem , Precursores de Proteínas/farmacologia , ATPases Translocadoras de Prótons/metabolismo , Receptores Purinérgicos P2Y12/metabolismo , Retina , Timosina/análogos & derivados , Animais , Hidrólise/efeitos dos fármacos , Masculino , Camundongos Endogâmicos C57BL , ATPases Mitocondriais Próton-Translocadoras/metabolismo , Proteínas Recombinantes/metabolismo , Timosina/administração & dosagem , Timosina/farmacologia
6.
Biochem Biophys Res Commun ; 522(1): 264-269, 2020 01 29.
Artigo em Inglês | MEDLINE | ID: mdl-31759625

RESUMO

We previously showed that prothymosin alpha (ProTα) improves cerebral ischemia-induced motor dysfunction. Our recent study also demonstrated that heterozygous ProTα deletion exhibited an enhanced anxiety-like behavior in mice. However, it remains elusive which brain regions or cells are related to these phenotypes. Here we generated conditional Gγ7-specific ProTα knockout mice using G protein γ7 subunit gene (Gng7)-cre promoter to see the brain robustness roles of ProTα in the striatum and hippocampus. The younger conditional ProTα (Gng7) knockout mice at the age of 10 weeks showed no significant phenotypes in motor dysfunction in the Rotarod test and locomotor activity in the open-field test, whereas significant motor dysfunction was obtained by 15 min transient middle cerebral artery occlusion (tMCAO)-induced cerebral ischemia. The aged conditional ProTα (Gng7) knockout mice at the age of 20 weeks showed hypolocomotor activity with less center time in the open-field test and impaired motor coordination in the Rotarod test without ischemia. Thus, this study suggests that ProTα has important roles in the maintenance of motor coordination and anxiety-like behavior.


Assuntos
Ansiedade/genética , Subunidades gama da Proteína de Ligação ao GTP/genética , Locomoção , Precursores de Proteínas/genética , Timosina/análogos & derivados , Envelhecimento , Animais , Ansiedade/fisiopatologia , Isquemia Encefálica/genética , Isquemia Encefálica/fisiopatologia , Feminino , Deleção de Genes , Masculino , Camundongos , Camundongos Knockout , Desempenho Psicomotor , Timosina/genética
7.
J Neurochem ; 153(6): 772-789, 2020 06.
Artigo em Inglês | MEDLINE | ID: mdl-31454420

RESUMO

Tissue plasminogen activator (tPA) administration beyond 4.5 h of stroke symptoms is beneficial for patients but has an increased risk of cerebral hemorrhage. Thus, increasing the therapeutic window of tPA is important for stroke recovery. We previously showed that prothymosin alpha (ProTα) or its mimetic hexapeptide (P6Q) has anti-ischemic activity. Here, we examined the beneficial effects of ProTα or P6Q against delayed tPA-induced brain damage following middle cerebral artery occlusion (MCAO) or photochemically induced thrombosis in mice. Brain hemorrhage was observed by tPA administration during reperfusion at 4.5 and 6 h after MCAO. Co-administration of ProTα with tPA at 4.5 h inhibited hemorrhage and motor dysfunction 2-4 days, but not 7 days after MCAO. ProTα administration at 2 and 4.5 h after MCAO significantly inhibited tPA (4.5 h)-induced motor dysfunction and death more than 7 days. Administration of tPA caused the loss of tight junction proteins, zona occulden-1 and occludin, and up-regulation of matrix metalloproteinase-2/9, in a ProTα-reversible manner. P6Q administration abolished tPA (4.5 h)-induced hemorrhage and reversed tPA (6 h)-induced vascular damage and matrix metalloproteinase-2 and 9 up-regulation. Twice administrations of P6Q at 2 h alone and 6 h with tPA significantly improved motor dysfunction more than 7 days. In photochemically induced thrombosis ischemia, similar vascular leakage and neuronal damage (infarction and motor dysfunction) by late tPA (4.5 or 6 h) were also inhibited by P6Q. Thus, these studies suggest that co-administration with ProTα or P6Q would be beneficial to inhibit delayed tPA-induced hemorrhagic mechanisms in acute ischemic stroke.


Assuntos
Materiais Biomiméticos/uso terapêutico , Lesões Encefálicas/tratamento farmacológico , Isquemia Encefálica/tratamento farmacológico , Precursores de Proteínas/uso terapêutico , Timosina/análogos & derivados , Ativador de Plasminogênio Tecidual/toxicidade , Animais , Lesões Encefálicas/induzido quimicamente , Lesões Encefálicas/patologia , Isquemia Encefálica/induzido quimicamente , Isquemia Encefálica/patologia , Masculino , Camundongos , Camundongos Endogâmicos C57BL , Timosina/uso terapêutico
8.
Curr Med Chem ; 27(29): 4840-4854, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-31389310

RESUMO

Prothymosin alpha (ProTα) is a highly acidic polypeptide, ubiquitously expressed in almost all mammalian cells and tissues and consisting of 109 amino acids in humans. ProTα is known to act both, intracellularly, as an anti-apoptotic and proliferation mediator, and extracellularly, as a biologic response modifier mediating immune responses similar to molecules termed as "alarmins". Antibodies and immunochemical techniques for ProTα have played a leading role in the investigation of the biological role of ProTα, several aspects of which still remain unknown and contributed to unraveling the diagnostic and therapeutic potential of the polypeptide. This review deals with the so far reported antibodies along with the related immunodetection methodology for ProTα (immunoassays as well as immunohistochemical, immunocytological, immunoblotting, and immunoprecipitation techniques) and its application to biological samples of interest (tissue extracts and sections, cells, cell lysates and cell culture supernatants, body fluids), in health and disease states. In this context, literature information is critically discussed, and some concluding remarks are presented.


Assuntos
Anticorpos , Precursores de Proteínas , Timosina/análogos & derivados , Alarminas , Animais , Humanos , Precursores de Proteínas/imunologia , Precursores de Proteínas/fisiologia , Timosina/imunologia , Timosina/fisiologia
9.
Yakugaku Zasshi ; 139(11): 1403-1415, 2019.
Artigo em Japonês | MEDLINE | ID: mdl-31685737

RESUMO

For my Ph.D. research topic, I isolated endogenous morphine-like analgesic dipeptide, kyotorphin, which mediates Met-enkephalin release, and discovered kyotorphin synthetase, a putative receptor and antagonist. Furthermore, I succeeded in purifying µ-opioid receptor and functional reconstitution with purified G proteins. After receiving my full professor position at Nagasaki University in 1996, I worked on two topics of research, molecular mechanisms of chronic pain through lysophosphatidic acid (LPA) and identification and characterization of neuroprotective protein, prothymosin α. In a series of studies, we have shown that LPA signaling defines the molecular mechanisms of neuropathic pain and fibromyalgia in terms of development and maintenance. Above all, the discovery of feed-forward system in LPA production and pain memory may contribute to better understanding of chronic pain and future analgesic drug discovery. Regarding prothymosin α, we first discovered it as neuronal necrosis-inhibitory molecule through two independent mechanisms, such as toll-like receptor and F0/F1 ATPase, both which protect neurons through indirect mechanisms. Prothymosin α is released by non-classical and non-vesicular mechanisms on various stresses, such as ischemia, starvation, and heat-shock. Thus it may be called a new type of neuroprotective damage-associated molecular patterns (DAMPs)/Alarmins. Heterozygotic mice showed a defect in memory-learning and neurogenesis as well as anxiogenic behaviors. Small peptide, P6Q derived from prothymosin α retains neuroprotective actions, which include blockade of cerebral hemorrhage caused by late treatment with tissue plasminogen activator in the stroke model in mice.


Assuntos
Dor Crônica/etiologia , Dor Crônica/genética , Fármacos Neuroprotetores , Precursores de Proteínas , Receptores de Ácidos Lisofosfatídicos/fisiologia , Transdução de Sinais/fisiologia , Timosina/análogos & derivados , Animais , Endorfinas , Humanos , Camundongos , Precursores de Proteínas/metabolismo , ATPases Translocadoras de Prótons , Receptores de Ácidos Lisofosfatídicos/metabolismo , Receptores Opioides , Acidente Vascular Cerebral , Timosina/metabolismo , Receptores Toll-Like
10.
FASEB J ; 33(11): 13051-13061, 2019 11.
Artigo em Inglês | MEDLINE | ID: mdl-31589480

RESUMO

Polycystic kidney disease (PKD) is characterized by the expansion of fluid-filled cysts in the kidney, which impair the function of kidney and eventually leads to end-stage renal failure. It has been previously demonstrated that transgenic overexpression of prothymosin α (ProT) induces the development of PKD; however, the underlying mechanisms remain unclear. In this study, we used a mouse PKD model that sustains kidney-specific low-expression of Pkd1 to illustrate that aberrant up-regulation of ProT occurs in cyst-lining epithelial cells, and we further developed an in vitro cystogenesis model to demonstrate that the suppression of ProT is sufficient to reduce cyst formation. Next, we found that the expression of ProT was accompanied with prominent augmentation of protein acetylation in PKD, which results in the activation of downstream signal transducer and activator of transcription (STAT) 3. The pathologic role of STAT3 in PKD has been previously reported. We determined that this molecular mechanism of protein acetylation is involved with the interaction between ProT and STAT3; consequently, it causes the deprivation of histone deacetylase 3 from the indicated protein. Conclusively, these results elucidate the significant role of ProT, including protein acetylation and STAT3 activation in PKD, which represent potential for ameliorating the disease progression of PKD.-Chen, Y.-C., Su, Y.-C., Shieh, G.-S., Su, B.-H., Su, W.-C., Huang, P.-H., Jiang, S.-T., Shiau, A.-L., Wu, C.-L. Prothymosin α promotes STAT3 acetylation to induce cystogenesis in Pkd1-deficient mice.


Assuntos
Doenças Renais Policísticas/patologia , Precursores de Proteínas/fisiologia , Fator de Transcrição STAT3/metabolismo , Canais de Cátion TRPP/genética , Timosina/análogos & derivados , Acetilação , Animais , Progressão da Doença , Cães , Células HEK293 , Humanos , Células Madin Darby de Rim Canino , Camundongos , Camundongos Knockout , Doenças Renais Policísticas/metabolismo , Precursores de Proteínas/genética , Timosina/genética , Timosina/fisiologia
11.
Biochim Biophys Acta Proteins Proteom ; 1867(11): 140252, 2019 11.
Artigo em Inglês | MEDLINE | ID: mdl-31325636

RESUMO

Intrinsically disordered proteins (IDPs) explore diverse conformations in their free states and, a few of them, also in their molecular complexes. This functional plasticity is essential for the function of IDPs, although their dynamics in both free and bound states is poorly understood. NUPR1 is a protumoral multifunctional IDP, activated during the acute phases of pancreatitis. It interacts with DNA and other IDPs, such as prothymosin α (ProTα), with dissociation constants of ~0.5 µM, and a 1:1 stoichiometry. We studied the structure and picosecond-to-nanosecond (ps-ns) dynamics by using both NMR and SAXS in: (i) isolated NUPR1; (ii) the NUPR1/ProTα complex; and (iii) the NUPR1/double stranded (ds) GGGCGCGCCC complex. Our SAXS findings show that NUPR1 remained disordered when bound to either partner, adopting a worm-like conformation; the fuzziness of bound NUPR1 was also pinpointed by NMR. Residues with the largest values of the relaxation rates (R1, R1ρ, R2 and ηxy), in the free and bound species, were mainly clustered around the 30s region of the sequence, which agree with one of the protein hot-spots already identified by site-directed mutagenesis. Not only residues in this region had larger relaxation rates, but they also moved slower than the rest of the molecule, as indicated by the reduced spectral density approach (RSDA). Upon binding, the energy landscape of NUPR1 was not funneled down to a specific, well-folded conformation, but rather its backbone flexibility was kept, with distinct motions occurring at the hot-spot region.


Assuntos
Fatores de Transcrição Hélice-Alça-Hélice Básicos/química , DNA/química , Complexos Multiproteicos/química , Proteínas de Neoplasias/química , Precursores de Proteínas/química , Timosina/análogos & derivados , Humanos , Domínios Proteicos , Espalhamento a Baixo Ângulo , Timosina/química , Difração de Raios X
12.
Cancer Sci ; 110(4): 1208-1219, 2019 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-30719818

RESUMO

Prothymosin-α (PTMA) is a small, acidic protein that is usually transported into the nucleus and involves many cellular and immunological functions. Previous studies demonstrated that aberrant location of PTMA expression exists in human bladder cancer, but the role of PTMA protein expression remains elusive. In this study, we created ectopic nuclear or cytoplasmic PTMA expression in human bladder cancer cells by infecting lentiviruses carrying wild type or deleted nuclear localization signal of the PTMA gene. The in vivo tumorigenesis assay showed PTMA protein with deleted nuclear localization signal promotes J82 xenograft tumor growth in mice and shortens their survival more so than the wild type. Chromatin immunoprecipitation showed that wild-type PTMA protein binds to the PTEN promoter and enhances phosphatase and tensin homolog (PTEN) expression. Through immunoblot proteomics and in vivo ubiquitination studies, PTMA protein can bind with tripartite motif-containing protein 21 (TRIM21) and block its ubiquitination. Also, TRIM21 can downregulate both forms of PTMA protein. In human bladder tumors, loss of nuclear PTMA expression was an unfavorable prognostic indicator for shorter disease-free survival (hazard ratio, 1.54; P = 0.009). Our data support that nuclear PTMA protein serves as a tumor suppressor in bladder cancer through upregulating PTEN and orchestrating TRIM21 for the regulation of Nrf2 signaling.


Assuntos
Proteína 1 Associada a ECH Semelhante a Kelch/metabolismo , Fator 2 Relacionado a NF-E2/metabolismo , PTEN Fosfo-Hidrolase/metabolismo , Precursores de Proteínas/metabolismo , Ribonucleoproteínas/metabolismo , Transdução de Sinais , Timosina/análogos & derivados , Neoplasias da Bexiga Urinária/metabolismo , Animais , Biomarcadores , Linhagem Celular Tumoral , Modelos Animais de Doenças , Feminino , Regulação Neoplásica da Expressão Gênica , Xenoenxertos , Humanos , Camundongos , PTEN Fosfo-Hidrolase/genética , Prognóstico , Regiões Promotoras Genéticas , Precursores de Proteínas/genética , Timosina/genética , Timosina/metabolismo , Ubiquitinação , Neoplasias da Bexiga Urinária/genética , Neoplasias da Bexiga Urinária/mortalidade , Neoplasias da Bexiga Urinária/patologia
13.
Biochemistry ; 57(48): 6645-6648, 2018 12 04.
Artigo em Inglês | MEDLINE | ID: mdl-30430826

RESUMO

It was recently reported that human linker histone H1.0 and its chaperone prothymosin-α (ProTα) form an extremely disordered 1:1 complex with an ultrahigh affinity (equilibrium dissociation constant KD of ∼2 × 10-12 M) measured using a single-molecule Förster resonance energy transfer method. It was hypothesized that the ultrahigh affinity and extreme disorder may be required for the chaperone function of ProTα, in which it displaces the linker histone from condensed chromatin. Here, we measure the binding affinity for the ProTα-H1.0 complex using isothermal titration calorimetry and report a KD value of (4.6 ± 0.5) × 10-7 M. In addition, we show that ProTα facilitates the formation of the H1.0-nucleosome complex in vitro. The results of our study contrast with those of the previous report and provide new insights into the chaperone function of ProTα. Possible causes for the observed discrepancy in binding affinity are discussed.


Assuntos
Histonas/metabolismo , Precursores de Proteínas/metabolismo , Timosina/análogos & derivados , Sequência de Aminoácidos , Calorimetria , Transferência Ressonante de Energia de Fluorescência , Histonas/química , Histonas/genética , Humanos , Proteínas Intrinsicamente Desordenadas/química , Proteínas Intrinsicamente Desordenadas/genética , Proteínas Intrinsicamente Desordenadas/metabolismo , Cinética , Chaperonas Moleculares/química , Chaperonas Moleculares/genética , Chaperonas Moleculares/metabolismo , Complexos Multiproteicos/química , Complexos Multiproteicos/genética , Complexos Multiproteicos/metabolismo , Nucleossomos/química , Nucleossomos/metabolismo , Ligação Proteica , Precursores de Proteínas/química , Precursores de Proteínas/genética , Timosina/química , Timosina/genética , Timosina/metabolismo
14.
J Biol Inorg Chem ; 23(8): 1255-1263, 2018 12.
Artigo em Inglês | MEDLINE | ID: mdl-30187212

RESUMO

Prothymosin-α is a small, multifunctional intrinsically disordered protein associated with cell survival and proliferation which binds multiple Zn2+ ions and undergoes partial folding. The interaction between prothymosin-α and at least two of its protein targets is significantly enhanced in the presence of Zn2+ ions, suggesting that Zn2+ binding plays a role in the protein's function. The primary sequence of prothymosin-α is highly acidic, with almost 50% comprised of Asp and Glu, and is unusual for a Zn2+-binding protein as it lacks Cys and His residues. To gain a better understanding of the nature of the Zn2+-prothymosin-α interactions and the protein's ability to discriminate Zn2+ over other divalent cations (e.g., Ca2+, Co2+, Mg2+) we synthesized a set of three model peptides and characterized the effect of metal binding using electrospray ionization mass spectrometry (ESI MS) and circular dichroism (CD) spectroscopy. ESI MS data reveal that the native peptide model of the glutamic acid rich region binds 4 Zn2+ ions with apparent, stepwise Kd values that are, at highest, in the tens of micromolar range. A peptide model with the same amino acid composition as the native sequence, but with the residues arranged randomly, showed no evidence of structural change by CD upon introduction of Zn2+. These results suggest that the high net negative charge of the glutamic acid-rich region of prothymosin-α is not a sufficient criterion for Zn2+ to induce a structural change; rather, Zn2+ binding to prothymosin-α is sequence specific, providing important insight into the behavior of intrinsically disordered proteins.


Assuntos
Proteínas Intrinsicamente Desordenadas/metabolismo , Precursores de Proteínas/metabolismo , Timosina/análogos & derivados , Zinco/metabolismo , Sequência de Aminoácidos , Dicroísmo Circular , Humanos , Proteínas Intrinsicamente Desordenadas/química , Fragmentos de Peptídeos/síntese química , Fragmentos de Peptídeos/química , Fragmentos de Peptídeos/metabolismo , Ácido Poliglutâmico/síntese química , Ácido Poliglutâmico/química , Ácido Poliglutâmico/metabolismo , Ligação Proteica , Precursores de Proteínas/química , Espectrometria de Massas por Ionização por Electrospray , Temperatura , Timosina/química , Timosina/metabolismo
15.
J Phys Chem B ; 122(49): 11262-11270, 2018 12 13.
Artigo em Inglês | MEDLINE | ID: mdl-30230839

RESUMO

The malleability of intrinsically disordered proteins (IDPs) has generated great interest in understanding how their conformations respond to crowded cellular environments. Experiments can report gross properties such as fluorescence resonance energy transfer (FRET) efficiency but cannot resolve the conformational ensembles of IDPs and their interactions with macromolecular crowders. Computation can in principle provide the latter information but in practice has been hampered by the enormous expense for realistic modeling of IDPs and crowders and for sufficient conformational sampling. Here, taking advantage of a powerful method called FMAP (fast Fourier transform-based modeling of atomistic protein-crowder interactions), we computed how the conformational ensembles of three IDPs are modified in concentrated polyethylene glycol (PEG) 6000 solutions. We represented the IDPs at the all-atom level and the PEG molecules at a coarse-grained level and calculated the experimental observable, i.e., FRET efficiency. Whereas accounting for only steric repulsion of PEG led to overestimation of crowding effects, quantitative agreement with experimental data was obtained upon including mild IDP-PEG attraction. The present work demonstrates that realistic modeling of IDPs under crowded conditions for direct comparison with experiments is now achievable.


Assuntos
Proteínas Intrinsicamente Desordenadas/química , Transferência Ressonante de Energia de Fluorescência , Integrase de HIV/química , HIV-1/química , Simulação de Dinâmica Molecular , Coativador 3 de Receptor Nuclear/química , Polietilenoglicóis/química , Conformação Proteica , Domínios Proteicos , Precursores de Proteínas/química , Timosina/análogos & derivados
16.
Expert Opin Biol Ther ; 18(sup1): 89-94, 2018 07.
Artigo em Inglês | MEDLINE | ID: mdl-30063859

RESUMO

OBJECTIVES: Prothymosin α (ProTα) was reported to inhibit the neuronal necrosis by facilitating the plasma membrane localization of endocytosed glucose transporter 1/4 through an activation of putative Gi-coupled receptor. The present study aims to identify a novel ProTα target, which may lead to an activation of Gi-coupled receptor. METHODS: We used Gi-rich lipid rafts fraction of retinal cell line N18-RE-105 cells for affinity cross-linking. The biological confirmation that F0/F1 ATPase is a target protein complex was performed by cell-free experiments using ELISA-based binding assay, surface plasmon resonance assay and quartz crystal microbalance assay, and cell-based experiments to measure extracellular ATP level in the HUVECs culture. RESULTS: From the cross-linking study and above-mentioned protein-protein interaction assays, ATP5A1 and ATP5B, F1 ATPase subunits were found to ProTα binding target proteins. In the culture of HUVEC cells, furthermore, ProTα increased the extracellular ATP levels in a reversible manner by anti-ATP5A1- and ATP5B-antibodies. CONCLUSION: The present study suggests that ProTα may activate ecto-F0/F1 ATPase and produced ATP. This study leads to next subjects whether produced ATP and its metabolites, ADP or adenosine may activate corresponding Gi-coupled receptors.


Assuntos
Adenosina Trifosfatases/metabolismo , ATPases Translocadoras de Prótons/metabolismo , Receptores Imunológicos/metabolismo , Animais , Proteínas de Transporte/metabolismo , Células Cultivadas , Reagentes para Ligações Cruzadas/química , Células Endoteliais da Veia Umbilical Humana , Humanos , Camundongos , Necrose , Ligação Proteica , Precursores de Proteínas/metabolismo , Ratos , Ratos Endogâmicos F344 , Transdução de Sinais/fisiologia , Timosina/análogos & derivados , Timosina/metabolismo
17.
Expert Opin Biol Ther ; 18(sup1): 199-203, 2018 07.
Artigo em Inglês | MEDLINE | ID: mdl-30063862

RESUMO

OBJECTIVES: We reevaluated a lyophilized sample of thymosin fraction 5, stored for 37 years at room temperature, by high-resolution mass spectrometry in terms of stability and yet uncharacterized polypeptides that could be biological important substances. METHODS: A top-down proteomic platform based on high-performance liquid chromatography (HPLC) coupled to high-resolution LTQ-Orbitrap mass spectrometry (MS) was applied to molecular characterization of polypeptides present in thymosin fraction 5. RESULTS: We detected more than 100 monoisotopic masses corresponding to thymosin ß4 and truncated forms of ubiquitin, prothymosin α, thymosin ß4, and thymosin ß9. Additionally, we discovered a new polypeptide present in thymosin fraction 5 and identified it as intact SH3 domain-binding glutamic acid-rich-like protein 3. CONCLUSION: In spite of the well-known proteolytic processes inherent to the preparation of thymosin fraction 5, still uncharacterized polypeptides as well as truncated forms of already well-known thymosins are present in fraction 5 after long-term storage. Therefore, continuing characterization of thymosin fraction 5 is even nowadays highly promising.


Assuntos
Espectrometria de Massas/métodos , Timosina/análogos & derivados , Animais , Cromatografia Líquida de Alta Pressão , Estabilidade de Medicamentos , Armazenamento de Medicamentos , Liofilização , Humanos , Precursores de Proteínas/análise , Precursores de Proteínas/isolamento & purificação , Proteômica/métodos , Timosina/análise , Timosina/química , Timosina/isolamento & purificação , Fatores de Tempo , Ubiquitina/análise , Ubiquitina/isolamento & purificação
18.
Biochimie ; 154: 99-106, 2018 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-30096371

RESUMO

Thymosin α1 (Tα1), a hormone containing 28 amino acids, has been approved in several cancer therapies, but the lack of tumor-targeting hinders its full use in tumor treatment. We designed a new peptide by connecting Tα1 and RGDR, generating a product, Tα1-RGDR, where RGDR is located in the C-end with both tumor-homing and cell internalizing properties (C-end rule peptides, a consensus R/KXXR/K motif). This work aimed to study the antitumor and immunological activities of Tα1-RGDR, and its differences compared with the wild-type Tα1. The antitumor and immunological activities of Tα1-RGDR were measured using the B16F10 tumor and immunologic suppression models. Tα1-RGDR treatment led to significant inhibition of tumor growth at a dose at which Tα1 showed a slight effect in the B16F10 tumor growth model. In the immunologic suppression model, Tα1-RGDR shared almost equivalent immunomodulatory effect with Tα1. These results demonstrated the better therapeutic effects after treatment with Tα1-RGDR compared with Tα1. Moreover, both Tα1-RGDR and Tα1 shared a helical conformation in the presence of trifluoroethanol based on CD spectroscopy. Our dock information of Tα1-RGDR when combined with integrin αvß3 or neuropilin-1 further confirmed previous experimental results. All these findings suggest that Tα1-RGDR might be a useful therapy for tumors by overcoming its wild type limitation of tumor homing.


Assuntos
Antineoplásicos/química , Melanoma/metabolismo , Timosina/análogos & derivados , Animais , Antineoplásicos/farmacologia , Linhagem Celular Tumoral , Melanoma/tratamento farmacológico , Melanoma/patologia , Camundongos , Timalfasina , Timosina/química , Timosina/farmacologia
19.
Int J Pharm ; 547(1-2): 611-620, 2018 Aug 25.
Artigo em Inglês | MEDLINE | ID: mdl-29933059

RESUMO

Tumor-targeted therapy is an attractive strategy for cancer treatment. Peptide hormone thymosin α1 (Tα1) has been used against several diseases, including cancer, but its activity is pleiotropic. Herein, we designed a fusion protein Tα1-iRGD by introducing the tumor homing peptide iRGD to Tα1. Results show that Tα1-iRGD can promote T-cell activation and CD86 expression, thereby exerting better effect and stronger inhibitory against melanoma and lung cancer, respectively, than Tα1 in vivo. These effects are indicated by the reduced densities of tumor vessels and Tα1-iRGD accumulation in tumors. Moreover, compared with Tα1, Tα1-iRGD can attach more B16F10 and H460 cells and exhibits significantly better immunomodulatory activity in immunosuppression models induced by hydrocortisone. Circular dichroism spectroscopy and structural analysis results revealed that Tα1 and Tα1-iRGD both adopted a helical confirmation in the presence of trifluoroethanol, indicating the structural basis of their functions. These findings highlight the vital function of Tα1-iRGD in tumor-targeted therapy and suggest that Tα1-iRGD is a better antitumor drug than Tα1.


Assuntos
Adjuvantes Imunológicos/farmacologia , Antineoplásicos/farmacologia , Neoplasias Pulmonares/tratamento farmacológico , Melanoma/tratamento farmacológico , Oligopeptídeos/farmacologia , Proteínas Recombinantes de Fusão/farmacologia , Timosina/análogos & derivados , Adjuvantes Imunológicos/química , Adjuvantes Imunológicos/uso terapêutico , Animais , Antineoplásicos/química , Antineoplásicos/uso terapêutico , Antígeno B7-2/metabolismo , Linhagem Celular Tumoral , Proliferação de Células/efeitos dos fármacos , Dicroísmo Circular , Feminino , Humanos , Tolerância Imunológica/efeitos dos fármacos , Neoplasias Pulmonares/imunologia , Ativação Linfocitária/efeitos dos fármacos , Melanoma/imunologia , Camundongos , Camundongos Endogâmicos BALB C , Camundongos Endogâmicos C57BL , Camundongos Endogâmicos ICR , Camundongos Nus , Oligopeptídeos/química , Oligopeptídeos/uso terapêutico , Estrutura Secundária de Proteína , Proteínas Recombinantes de Fusão/química , Proteínas Recombinantes de Fusão/uso terapêutico , Linfócitos T/efeitos dos fármacos , Linfócitos T/imunologia , Linfócitos T/metabolismo , Timalfasina , Timosina/química , Timosina/farmacologia , Timosina/uso terapêutico , Trifluoretanol/química , Ensaios Antitumorais Modelo de Xenoenxerto
20.
Nature ; 555(7694): 61-66, 2018 03 01.
Artigo em Inglês | MEDLINE | ID: mdl-29466338

RESUMO

Molecular communication in biology is mediated by protein interactions. According to the current paradigm, the specificity and affinity required for these interactions are encoded in the precise complementarity of binding interfaces. Even proteins that are disordered under physiological conditions or that contain large unstructured regions commonly interact with well-structured binding sites on other biomolecules. Here we demonstrate the existence of an unexpected interaction mechanism: the two intrinsically disordered human proteins histone H1 and its nuclear chaperone prothymosin-α associate in a complex with picomolar affinity, but fully retain their structural disorder, long-range flexibility and highly dynamic character. On the basis of closely integrated experiments and molecular simulations, we show that the interaction can be explained by the large opposite net charge of the two proteins, without requiring defined binding sites or interactions between specific individual residues. Proteome-wide sequence analysis suggests that this interaction mechanism may be abundant in eukaryotes.


Assuntos
Histonas/química , Histonas/metabolismo , Proteínas Intrinsicamente Desordenadas/química , Proteínas Intrinsicamente Desordenadas/metabolismo , Precursores de Proteínas/química , Precursores de Proteínas/metabolismo , Timosina/análogos & derivados , Sítios de Ligação , Humanos , Ligação Proteica , Eletricidade Estática , Timosina/química , Timosina/metabolismo
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