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1.
Int Immunopharmacol ; 133: 112079, 2024 May 30.
Artigo em Inglês | MEDLINE | ID: mdl-38615376

RESUMO

Porcine rotavirus (PoRV) poses a threat to the development of animal husbandry and human health, leading to substantial economic losses. VP6 protein is the most abundant component in virus particles and also the core structural protein of the virus. Firstly, this study developed an antibiotic-resistance-free, environmentally friendly expression vector, named asd-araC-PBAD-alr (AAPA). Then Recombinant Lactiplantibacillus plantarum (L. plantarum) strains induced by arabinose to express VP6 and VP6-pFc fusion proteins was constructed. Subsequently, This paper discovered that NC8/Δalr-pCXa-VP6-S and NC8/Δalr-pCXa-VP6-pFc-S could enhance host immunity and prevent rotavirus infection in neonatal mice and piglets. The novel recombinant L. plantarum strains constructed in this study can serve as oral vaccines to boost host immunity, offering a new strategy to prevent PoRV infection.


Assuntos
Proteínas do Capsídeo , Lactobacillus plantarum , Doenças dos Suínos , Animais , Suínos , Lactobacillus plantarum/imunologia , Proteínas do Capsídeo/imunologia , Proteínas do Capsídeo/genética , Camundongos , Doenças dos Suínos/prevenção & controle , Doenças dos Suínos/virologia , Doenças dos Suínos/microbiologia , Doenças dos Suínos/imunologia , Infecções por Rotavirus/prevenção & controle , Infecções por Rotavirus/imunologia , Infecções por Rotavirus/virologia , Antígenos Virais/imunologia , Rotavirus/imunologia , Camundongos Endogâmicos BALB C , Animais Recém-Nascidos
2.
Zhongguo Shi Yan Xue Ye Xue Za Zhi ; 31(4): 1061-1068, 2023.
Artigo em Chinês | MEDLINE | ID: mdl-37551478

RESUMO

OBJECTIVE: To study the role of cytokines and lymphocyte subsets in the diagnosis, prognosis and efficacy evaluation of DLBCL patients, and the effects of Tislelizumab on immune function and cytokines in DLBCL patients. METHODS: Twenty-three patients with newly diagnosed DLBCL were selected as DLBCL group and 34 patients with megaloblastic anemia as the control group. The levels of peripheral blood cytokines IL-2, IL-4, IL-6, IL-10, TNF- α and IFN-γ by ELISA method. The levels of peripheral blood CD3+, CD4+, CD8+ T lymphocytes, B lymphocytes and NK cells, the ratio of CD4+/CD8+ were detected by flow cytometry. The levels of cytokins and lymphocyto subsets in DLBCL patients with different clinical data and different therapeutic effects were compared. RESULTS: The levels of cytokines IL-2, IL-6 and IL-10 in DLBCL group were significantly higher than those in control group, but there was no significant correlation between cytokine levels and age and gender. The higher IPI score, higher Ann Arbor stage, B symptoms, higher ß 2-MG, LDH and CRP levels, IL-6 and IL-10 levels were significantly higher, and IL-4 was also significantly higher in patients with high LDH levels. Compared with the ineffective group, the levels of IL-6 and IL-10 were significantly lower and the level of CD4+ T cells and the ratio of CD4+/CD8+ was significantly higher in the effective group before therapy. The levels of IL-6, IL-10 and B lymphocytes in the effective group decreased significantly after therapy compared to those before therapy. After 4 cycles of therapy, the level of IL-2 and the ratio of CD4+/CD8+ in the Tislelizumab group were significantly higher than those in the non-Tislelizumab group, and the level of CD8+ T cells was significantly lower than that in the non-Tislelizumab group(P<0.05). The level of B lymphocytes in both the Tislelizumab group and the non-Tislelizumab group after therapy was significantly lower than that before therapy. CONCLUSION: The expression of cytokines and lymphocyte subsets in peripheral blood of patients with DLBCL is abnormal, which is related to the severity, prognosis and therapeutic effect of the disease. Tislelizumab can improve the immune function of patients with DLBCL by affecting cytokines and lymphocyte subsets and strengthen anti-tumor immunity.

3.
World J Clin Cases ; 11(18): 4295-4305, 2023 Jun 26.
Artigo em Inglês | MEDLINE | ID: mdl-37449216

RESUMO

BACKGROUND: The Coexistence of myeloid and lymphoid malignancies is rare. Myeloid leukemia occurs more frequently as a secondary event in patients receiving chemotherapy agents for lymphoid malignancies. Synchronous diagnoses of diffuse large B-cell lymphoma (DLBCL), acute myeloid leukemia (AML), and untreated lymphoplasmacytic lymphoma/Waldenström macroglobulinemia (LPL/WM) in the same patient have not been reported. Here we report one such case. CASE SUMMARY: An 89-year-old man had a chest wall mass histopathologically diagnosed as DLBCL. The bone marrow and peripheral blood contained two groups of cells. One group of cells fulfilled the criteria of AML, and the other revealed the features of small B lymphocytic proliferative disorder, which we considered LPL/WM. Multiple chromosomal or genetic changes were detected in bone marrow mononuclear cells, including ATM deletion, CCND1 amplification, mutations of MYD88 (L265P) and TP53, WT1 overexpression, and fusion gene of BIRC2-ARAP1, as well as complex chromosomal abnormalities. The patient refused chemotherapy because of old age and died of pneumonia 1 mo after the final diagnosis. CONCLUSION: The coexistence of DLBCL, AML, and untreated LPL/WM in the same patient is extremely rare, which probably results from multiple steps of genetic abnormalities. Asymptomatic LPL/WM might have occurred first, then myelodysplastic syndrome-related AML developed, and finally aggressive DLBCL arose. Therefore, medical staff should pay attention to this rare phenomenon to avoid misdiagnoses.

4.
Proc Natl Acad Sci U S A ; 119(49): e2209256119, 2022 12 06.
Artigo em Inglês | MEDLINE | ID: mdl-36454752

RESUMO

Auxin inactivation is critical for plant growth and development. To develop plant growth regulators functioning in auxin inactivation pathway, we performed a phenotype-based chemical screen in Arabidopsis and identified a chemical, nalacin, that partially mimicked the effects of auxin. Genetic, pharmacological, and biochemical approaches demonstrated that nalacin exerts its auxin-like activities by inhibiting indole-3-acetic acid (IAA) conjugation that is mediated by Gretchen Hagen 3 (GH3) acyl acid amido synthetases. The crystal structure of Arabidopsis GH3.6 in complex with D4 (a derivative of nalacin) together with docking simulation analysis revealed the molecular basis of the inhibition of group II GH3 by nalacin. Sequence alignment analysis indicated broad bioactivities of nalacin and D4 as inhibitors of GH3s in vascular plants, which were confirmed, at least, in tomato and rice. In summary, our work identifies nalacin as a potent inhibitor of IAA conjugation mediated by group II GH3 that plays versatile roles in hormone-regulated plant development and has potential applications in both basic research and agriculture.


Assuntos
Arabidopsis , Ligases , Arabidopsis/genética , Ácidos Indolacéticos/farmacologia , Fenômenos Químicos , Reguladores de Crescimento de Plantas/farmacologia , Testes Genéticos
5.
Elife ; 112022 10 13.
Artigo em Inglês | MEDLINE | ID: mdl-36227650

RESUMO

A newly discovered pathway suggests histone proteins H3 and H4 are imported into the nucleus as individual units rather than joined together as heterodimers as was previously thought.


Assuntos
Núcleo Celular , Histonas , Transporte Ativo do Núcleo Celular , Núcleo Celular/metabolismo , Histonas/metabolismo
6.
Nat Commun ; 13(1): 4680, 2022 08 09.
Artigo em Inglês | MEDLINE | ID: mdl-35945219

RESUMO

DPF3, a component of the SWI/SNF chromatin remodeling complex, has been associated with clear cell renal cell carcinoma (ccRCC) in a genome-wide association study. However, the functional role of DPF3 in ccRCC development and progression remains unknown. In this study, we demonstrate that DPF3a, the short isoform of DPF3, promotes kidney cancer cell migration both in vitro and in vivo, consistent with the clinical observation that DPF3a is significantly upregulated in ccRCC patients with metastases. Mechanistically, DPF3a specifically interacts with SNIP1, via which it forms a complex with SMAD4 and p300 histone acetyltransferase (HAT), the major transcriptional regulators of TGF-ß signaling pathway. Moreover, the binding of DPF3a releases the repressive effect of SNIP1 on p300 HAT activity, leading to the increase in local histone acetylation and the activation of cell movement related genes. Overall, our findings reveal a metastasis-promoting function of DPF3, and further establish the link between SWI/SNF components and ccRCC.


Assuntos
Carcinoma de Células Renais , Neoplasias Renais , Transdução de Sinais , Carcinoma de Células Renais/genética , Cromatina , Montagem e Desmontagem da Cromatina , Proteínas de Ligação a DNA/metabolismo , Estudo de Associação Genômica Ampla , Humanos , Neoplasias Renais/genética , Fatores de Transcrição/metabolismo , Fator de Crescimento Transformador beta/metabolismo
7.
J Mol Biol ; 434(19): 167756, 2022 10 15.
Artigo em Inglês | MEDLINE | ID: mdl-35870648

RESUMO

Histone chaperones, which constitute an interaction and functional network involved in all aspects of histone metabolism, have to date been identified only in eukaryotes. The Epstein-Barr virus tegument protein BKRF4 is a histone-binding protein that engages histones H2A-H2B and H3-H4, and cellular chromatin, inhibiting the host DNA damage response. Here, we identified BKRF4 as a bona fide viral histone chaperone whose histone-binding domain (HBD) forms a co-chaperone complex with the human histone chaperone ASF1 in vitro. We determined the crystal structures of the quaternary complex of the BKRF4 HBD with human H3-H4 dimer and the histone chaperone ASF1b and the ternary complex of the BKRF4 HBD with human H2A-H2B dimer. Through structural and biochemical studies, we elucidated the molecular basis for H3-H4 and H2A-H2B recognition by BKRF4. We also revealed two conserved motifs, D/EL and DEF/Y/W, within the BKRF4 HBD, which may represent common motifs through which histone chaperones target H3-H4 and H2A-H2B, respectively. In conclusion, our results identify BKRF4 as a histone chaperone encoded by the Epstein-Barr virus, representing a typical histone chaperone found in a non-eukaryote. We envision that more histone chaperones await identification and characterization in DNA viruses and even archaea.


Assuntos
Proteínas do Capsídeo , Proteínas de Ciclo Celular , Herpesvirus Humano 4 , Chaperonas de Histonas , Proteínas do Capsídeo/química , Proteínas de Ciclo Celular/química , Cromatina/química , Herpesvirus Humano 4/genética , Chaperonas de Histonas/química , Histonas/metabolismo , Humanos , Ligação Proteica , Conformação Proteica
8.
J Integr Plant Biol ; 64(12): 2309-2313, 2022 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-35587028

RESUMO

The structural basis for histone recognition by the histone chaperone nuclear autoantigenic sperm protein (NASP) remains largely unclear. Here, we showed that Arabidopsis thaliana AtNASP is a monomer and displays robust nucleosome assembly activity in vitro. Examining the structure of AtNASP complexed with a histone H3 α3 peptide revealed a binding mode that is conserved in human NASP. AtNASP recognizes the H3 N-terminal region distinct from human NASP. Moreover, AtNASP forms a co-chaperone complex with ANTI-SILENCING FUNCTION 1 (ASF1) by binding to the H3 N-terminal region. Therefore, we deciphered the structure of AtNASP and the basis of the AtNASP-H3 interaction.


Assuntos
Arabidopsis , Histonas , Masculino , Humanos , Histonas/metabolismo , Arabidopsis/metabolismo , Chaperonas Moleculares/metabolismo , Sementes/metabolismo , Proteínas de Ciclo Celular/química , Proteínas de Ciclo Celular/metabolismo , Ligação Proteica , Autoantígenos/metabolismo , Proteínas Nucleares/metabolismo
9.
Nucleic Acids Res ; 50(9): 5349-5368, 2022 05 20.
Artigo em Inglês | MEDLINE | ID: mdl-35489058

RESUMO

Histone chaperones regulate all aspects of histone metabolism. NASP is a major histone chaperone for H3-H4 dimers critical for preventing histone degradation. Here, we identify two distinct histone binding modes of NASP and reveal how they cooperate to ensure histone H3-H4 supply. We determine the structures of a sNASP dimer, a complex of a sNASP dimer with two H3 α3 peptides, and the sNASP-H3-H4-ASF1b co-chaperone complex. This captures distinct functionalities of NASP and identifies two distinct binding modes involving the H3 α3 helix and the H3 αN region, respectively. Functional studies demonstrate the H3 αN-interaction represents the major binding mode of NASP in cells and shielding of the H3 αN region by NASP is essential in maintaining the H3-H4 histone soluble pool. In conclusion, our studies uncover the molecular basis of NASP as a major H3-H4 chaperone in guarding histone homeostasis.


Assuntos
Chaperonas de Histonas , Histonas , Chaperonas de Histonas/metabolismo , Histonas/metabolismo , Homeostase , Chaperonas Moleculares/metabolismo , Ligação Proteica
10.
BMC Oral Health ; 22(1): 87, 2022 03 23.
Artigo em Inglês | MEDLINE | ID: mdl-35321697

RESUMO

BACKGROUND: Autologous platelet concentrate has been widely used to encourage the regeneration of hard and soft tissues. Up to now, there are three generations of autologous platelet concentrates. Many studies have shown that the three autologous concentrates have different effects, but the specific diversities have not been studied. The purpose of this study was to explore and compare the effects of platelet-rich fibrin, concentrated growth factor and platelet-poor plasma on the healing of tooth extraction sockets in New Zealand rabbits. METHODS: A total of 24 healthy male New Zealand white rabbits aged 8-12 weeks were selected. The experimental animals were randomly divided into four groups: three experimental groups were respectively implanted with PPP, CGF and PRF gel after bilateral mandibular anterior teeth were extracted, and the control group did not implant any material. The alveolar bone of the mandibular anterior region was taken at 2, 4 and 8 weeks after operation. The height and width of the extraction wound were detected by CBCT, the growth of the new bone was observed by HE and Masson staining, and the expression of osteogenic genes was detected by real-time PCR. Data were analyzed using IBM SPSS statistical package 22.0. RESULTS: The radiological results showed that alveolar bone resorption in all groups gradually increased over time. However, the experimental groups showed lower amounts of bone resorption. The histological results showed that new bone formation was observed in all groups. Over time, the new bone trabeculae of the CGF group became closely aligned while those in the PPP and PRF groups remained scattered. PCR results showed that the expression of BMP-2 and ALP was higher in the experimental groups than the control group. CONCLUSION: In conclusion, the application of PRF, CGF and PPP in tooth extraction sockets effectively promoted bone regeneration. CGF showed more effective bone induction and tissue regeneration ability in the long term.


Assuntos
Perda do Osso Alveolar , Fibrina Rica em Plaquetas , Animais , Masculino , Coelhos , Perda do Osso Alveolar/patologia , Peptídeos e Proteínas de Sinalização Intercelular , Extração Dentária/métodos , Alvéolo Dental/cirurgia
11.
Medicine (Baltimore) ; 101(5): e28651, 2022 Feb 04.
Artigo em Inglês | MEDLINE | ID: mdl-35119009

RESUMO

RATIONALE: POEMS (polyneuropathy, organomegaly, endocrinopathy, M protein, and skin changes) syndrome is a rare and complicated disease related to multiple organs and systems. Here, we report a case of systemic mastocytosis (SM) that was misdiagnosed as a POEMS syndrome. PATIENT CONCERNS: A 42-year-old man presented with skin changes, diarrhea, and limb numbness. DIAGNOSES: Positron emission tomography/computed tomography revealed extravascular volume overload, organomegaly, lymphadenopathy, and bone lesions with mixed lesions of osteosclerosis and osteolysis. Therefore, POEMS syndrome was suspected. Further histopathological and immunohistochemical examination of the bone marrow, lymph nodes, and gastric mucosa suggested a diagnosis of mastocytosis. The c-Kit D816V mutation confirmed the diagnosis of SM. INTERVENTIONS: The patient received the treatment of pegylated interferon-alpha weekly and glucocorticoid daily. OUTCOMES: The symptoms relieved significantly. LESSONS: There are many similar features between POEMS syndrome and SM, probably leading to misdiagnosis. This study analyzed the different points between them which can provide help for differentiation.


Assuntos
Mastocitose Sistêmica , Osteosclerose , Adulto , Medula Óssea , Diagnóstico Diferencial , Erros de Diagnóstico , Humanos , Linfonodos , Masculino , Mastocitose Sistêmica/diagnóstico , Osteosclerose/diagnóstico , Síndrome POEMS/diagnóstico
12.
Mol Cell ; 81(12): 2533-2548.e9, 2021 06 17.
Artigo em Inglês | MEDLINE | ID: mdl-33857403

RESUMO

From biosynthesis to assembly into nucleosomes, histones are handed through a cascade of histone chaperones, which shield histones from non-specific interactions. Whether mechanisms exist to safeguard the histone fold during histone chaperone handover events or to release trapped intermediates is unclear. Using structure-guided and functional proteomics, we identify and characterize a histone chaperone function of DNAJC9, a heat shock co-chaperone that promotes HSP70-mediated catalysis. We elucidate the structure of DNAJC9, in a histone H3-H4 co-chaperone complex with MCM2, revealing how this dual histone and heat shock co-chaperone binds histone substrates. We show that DNAJC9 recruits HSP70-type enzymes via its J domain to fold histone H3-H4 substrates: upstream in the histone supply chain, during replication- and transcription-coupled nucleosome assembly, and to clean up spurious interactions. With its dual functionality, DNAJC9 integrates ATP-resourced protein folding into the histone supply pathway to resolve aberrant intermediates throughout the dynamic lives of histones.


Assuntos
Proteínas de Choque Térmico HSP40/metabolismo , Chaperonas de Histonas/metabolismo , Linhagem Celular Tumoral , Cromatina , Montagem e Desmontagem da Cromatina , Replicação do DNA , Proteínas de Choque Térmico HSP40/fisiologia , Proteínas de Choque Térmico HSP70/metabolismo , Células HeLa , Chaperonas de Histonas/fisiologia , Histonas/metabolismo , Humanos , Componente 2 do Complexo de Manutenção de Minicromossomo/metabolismo , Modelos Moleculares , Chaperonas Moleculares/metabolismo , Nucleossomos , Ligação Proteica , Proteômica/métodos
13.
Hematology ; 25(1): 356-365, 2020 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-33054609

RESUMO

OBJECTIVES: Haploidentical hematopoietic stem cell transplantation (Haplo-SCT) and matched unrelated donor transplantation (MUD-SCT) are two important options when a matched sibling donor (MSD) is unavailable. Several studies comparing Haplo-SCT and MUD-SCT have reported inconsistent clinical outcomes. Therefore, it is necessary to synthesize the existing evidence regarding outcomes of stem cell transplantations comparing Haplo-SCT with MUD-SCT. METHODS: We searched for titles of articles in MEDLINE (PubMed), Cochrane library, EMBASE database that compared transplantation with Haplo-SCT versus MUD-SCT. To compare clinical outcomes between Haplo-SCT and MUD-SCT, we performed a meta-analysis of 17 studies and reported the pooled odd ratios (OR) of 6 endpoints including overall survival (OS), progression free survival (PFS), non-relapse mortality (NRM), relapse rate (RR), acute graft-versus-host disease (aGVHD) and chronic graft- versus-host disease (cGVHD). RESULTS: We found that Haplo-SCT was associated with a comparable OS (pooled OR of 0.99, 95% Confidence Interval (CI) 0.86-1.14), PFS (OR 1.00, 95% CI 0.88-1.15), NRM (OR 0.83, 95% CI 0.65-1.04) and RR (OR 1.08, 95% CI 0.95-1.22) compared to MUD-SCT. We also found a significantly decreased risk of aGVHD (OR 0.74, 95% CI 0.62-0.88) and cGVHD (OR 0.50, 95% CI 0.38-0.66) in Haplo-SCT group. CONCLUSION: Results of this meta-analysis demonstrates that Haplo-SCT achieves comparable clinical outcomes compared to MUD-SCT in terms of OS, PFS, TRM and RR, but is better than MUD-SCT in terms of decreased aGVHD and cGVHD risk. Haplo-SCT is a valid option for patient needing urgent transplantation.


Assuntos
Doença Enxerto-Hospedeiro , Neoplasias Hematológicas , Transplante de Células-Tronco Hematopoéticas , Condicionamento Pré-Transplante , Doadores não Relacionados , Adulto , Aloenxertos , Intervalo Livre de Doença , Feminino , Doença Enxerto-Hospedeiro/etiologia , Doença Enxerto-Hospedeiro/mortalidade , Doença Enxerto-Hospedeiro/terapia , Neoplasias Hematológicas/mortalidade , Neoplasias Hematológicas/terapia , Humanos , Masculino
14.
Nucleic Acids Res ; 47(19): 10388-10399, 2019 11 04.
Artigo em Inglês | MEDLINE | ID: mdl-31504793

RESUMO

HMCES and yedK were recently identified as sensors of abasic sites in ssDNA. In this study, we present multiple crystal structures captured in the apo-, nonspecific-substrate-binding, specific-substrate-binding, and product-binding states of yedK. In combination with biochemical data, we unveil the molecular basis of AP site sensing in ssDNA by yedK. Our results indicate that yedK has a strong preference for AP site-containing ssDNA over native ssDNA and that the conserved Glu105 residue is important for identifying AP sites in ssDNA. Moreover, our results reveal that a thiazolidine linkage is formed between yedK and AP sites in ssDNA, with the residues that stabilize the thiazolidine linkage important for the formation of DNA-protein crosslinks between yedK and the AP sites. We propose that our findings offer a unique platform to develop yedK and other SRAP domain-containing proteins as tools for detecting abasic sites in vitro and in vivo.


Assuntos
DNA de Cadeia Simples/genética , Proteínas de Ligação a DNA/genética , Conformação Proteica , Uracila-DNA Glicosidase/genética , Sítios de Ligação/genética , Escherichia coli/genética , Resposta SOS em Genética , Especificidade por Substrato , Tiazolidinas/química
15.
Nat Struct Mol Biol ; 26(7): 571-582, 2019 07.
Artigo em Inglês | MEDLINE | ID: mdl-31235911

RESUMO

Vasohibins are tubulin tyrosine carboxypeptidases that are important in neuron physiology. We examined the crystal structures of human vasohibin 1 and 2 in complex with small vasohibin-binding protein (SVBP) in the absence and presence of different inhibitors and a C-terminal α-tubulin peptide. In combination with functional data, we propose that SVBP acts as an activator of vasohibins. An extended groove and a distinctive surface residue patch of vasohibins define the specific determinants for recognizing and cleaving the C-terminal tyrosine of α-tubulin and for binding microtubules, respectively. The vasohibin-SVBP interaction and the ability of the enzyme complex to associate with microtubules regulate axon specification of neurons. Our results define the structural basis of tubulin detyrosination by vasohibins and show the relevance of this process for neuronal development. Our findings offer a unique platform for developing drugs against human conditions with abnormal tubulin tyrosination levels, such as cancer, heart defects and possibly brain disorders.


Assuntos
Proteínas Angiogênicas/metabolismo , Proteínas de Transporte/metabolismo , Proteínas de Ciclo Celular/metabolismo , Tubulina (Proteína)/metabolismo , Proteínas Angiogênicas/química , Animais , Proteínas de Transporte/química , Proteínas de Ciclo Celular/química , Células Cultivadas , Cristalografia por Raios X , Células HEK293 , Humanos , Camundongos , Modelos Moleculares , Conformação Proteica , Mapas de Interação de Proteínas , Tubulina (Proteína)/química
16.
Nucleic Acids Res ; 45(20): 12005-12014, 2017 Nov 16.
Artigo em Inglês | MEDLINE | ID: mdl-29036323

RESUMO

PUF (Pumilio/fem-3 mRNA binding factor) proteins, a conserved family of RNA-binding proteins, recognize specific single-strand RNA targets in a specific modular way. Although plants have a greater number of PUF protein members than do animal and fungal systems, they have been the subject of fewer structural and functional investigations. The aim of this study was to elucidate the involvement of APUM23, a nucleolar PUF protein in the plant Arabidopsis, in pre-rRNA processing. APUM23 is distinct from classical PUF family proteins, which are located in the cytoplasm and bind to 3'UTRs of mRNA to modulate mRNA expression and localization. We found that the complete RNA target sequence of APUM23 comprises 11 nt in 18S rRNA at positions 1141-1151. The complex structure shows that APUM23 has 10 PUF repeats; it assembles into a C-shape, with an insertion located within the inner concave surface. We found several different RNA recognition features. A notable structural feature of APUM23 is an insertion in the third PUF repeat that participates in nucleotide recognition and maintains the correct conformation of the target RNA. Our findings elucidate the mechanism for APUM23's-specific recognition of 18S rRNA.


Assuntos
Proteínas de Arabidopsis/metabolismo , RNA de Plantas/metabolismo , RNA Ribossômico 18S/metabolismo , Proteínas de Ligação a RNA/metabolismo , Proteínas de Arabidopsis/química , Proteínas de Arabidopsis/genética , Sequência de Bases , Sítios de Ligação/genética , Calorimetria/métodos , Cristalografia por Raios X , Modelos Moleculares , Mutação , Conformação de Ácido Nucleico , Ligação Proteica , Domínios Proteicos , Estrutura Secundária de Proteína , RNA de Plantas/química , RNA de Plantas/genética , RNA Ribossômico 18S/química , RNA Ribossômico 18S/genética , Proteínas de Ligação a RNA/química , Proteínas de Ligação a RNA/genética , Termodinâmica
17.
FEBS J ; 284(20): 3422-3436, 2017 10.
Artigo em Inglês | MEDLINE | ID: mdl-28815970

RESUMO

The acetylation of lysine 56 of histone H3 (H3K56ac) enhances the binding affinity of histone chaperones to H3-H4 dimers. CREB-binding protein (CBP) possesses a bromodomain that recognizes H3K56 acetylation. CBP also possesses a histone acetyltransferase (HAT) domain, which has been shown to promote H3K56 acetylation of free histones to facilitate delivery of replication-dependent chaperones to acetylated histones for chromatin assembly. However, the mechanism by which the CBP bromodomain recognizes H3K56ac and the context in which such recognition occurs remain elusive. Here, we solved the crystal structure of the CBP bromodomain in complex with an H3K56ac peptide. Our data demonstrate that the CBP bromodomain recognizes H3K56ac with high affinity. Structural and affinity analyses reveal that the CBP bromodomain prefers an aromatic residue at the -2 position and an arginine at the -4 position from the acetyl-lysine, and that the CBP bromodomain selectively recognizes an extended conformation of the H3 αN helix that contains H3K56ac. We also demonstrate that the CBP bromodomain binds to H3K56ac in a recombinant H3-H4 dimer but not in a mono-nucleosome. Our results suggest that the CBP bromodomain selectively recognizes an extended conformation of the K56-acetylated H3 αN region within an H3-H4 dimer, which is expected to facilitate the HAT activity of CBP for subsequent H3K56 acetylation of free histones. DATABASES: Coordinates of the CBP bromodomain in complex with H3K56ac as described in this article have been deposited in the PDB with accession number 5GH9.


Assuntos
Proteína de Ligação a CREB/metabolismo , Histonas/química , Histonas/metabolismo , Processamento de Proteína Pós-Traducional , Acetilação , Sítios de Ligação , Proteína de Ligação a CREB/química , Cristalografia por Raios X , Histona Acetiltransferases/metabolismo , Humanos , Lisina/química , Lisina/metabolismo , Nucleossomos/metabolismo , Fragmentos de Peptídeos/química , Fragmentos de Peptídeos/metabolismo , Ligação Proteica , Domínios Proteicos , Estrutura Terciária de Proteína
18.
FEBS J ; 284(7): 1082-1095, 2017 04.
Artigo em Inglês | MEDLINE | ID: mdl-28207202

RESUMO

Tripartite motif-containing protein 24 (TRIM24) is closely correlated with multiple cancers, and a recent study demonstrated that the bromodomain of TRIM24 is essential for the proliferation of lethal castration-resistant prostate cancer. Here, we identify three new inhibitors of the TRIM24 bromodomain using NMR fragment-based screening. The crystal structures of two new inhibitors in complex with the TRIM24 bromodomain reveal that the water-bridged interaction network is conserved in the same fashion as those for known benzoimidazolone inhibitors. Interestingly, the polar substitution on the warhead of one new inhibitor pulls the whole ligand approximately 2 Å into the inner side pocket of the TRIM24 bromodomain, and thus exhibits a binding mode significantly different from other known bromodomain ligands. This mode provides a useful handle for further hit-to-lead evolution toward novel inhibitors of the TRIM24 bromodomain. DATABASE: Structural data are available in the PDB under the accession numbers 5H1T, 5H1U, and 5H1V.


Assuntos
Benzimidazóis/química , Proteínas de Transporte/química , Água/química , Motivos de Aminoácidos , Sítios de Ligação , Proteínas de Transporte/genética , Clonagem Molecular , Cristalografia por Raios X , Escherichia coli/genética , Escherichia coli/metabolismo , Expressão Gênica , Humanos , Ligação de Hidrogênio , Interações Hidrofóbicas e Hidrofílicas , Ligantes , Modelos Moleculares , Ressonância Magnética Nuclear Biomolecular , Ligação Proteica , Domínios e Motivos de Interação entre Proteínas , Estrutura Secundária de Proteína , Proteínas Recombinantes/química , Proteínas Recombinantes/genética , Proteínas Recombinantes/metabolismo , Relação Estrutura-Atividade
19.
Zhongguo Shi Yan Xue Ye Xue Za Zhi ; 24(5): 1466-1469, 2016 Oct.
Artigo em Chinês | MEDLINE | ID: mdl-27784376

RESUMO

OBJECTIVE: To investigate the expression level of S100A6 mRNA in MM and to its clinical significance, and to evaluate its significance. METHODS: The expression level of S100A6 mRNA in MM patients was determined by real time quantitative PCR(RQ-PCR), and its relationship with the clinical features and outcomes of patients was analyzed by statistic method. RESULTS: S100A6 mRNA was detected in 20 MM patients. Compared with normal persons, the S100A6 mRNA expression in MM patients was higher. In different groups, the S100A6 mRNA expression in MM patients of 3 stages was higer than that in patients of 1 and 2 stages. MM patients with higher S100A6 mRNA expression had poor prognosis and higer extramedullary metastasis rate. CONCLUSION: The high expression of S100A6 mRNA is associated with poor prognosis and may be a prognostic molecular marker of MM.


Assuntos
Mieloma Múltiplo , Proteínas de Ciclo Celular , Humanos , RNA Mensageiro , Reação em Cadeia da Polimerase em Tempo Real , Proteína A6 Ligante de Cálcio S100
20.
J Biol Chem ; 291(32): 16709-19, 2016 08 05.
Artigo em Inglês | MEDLINE | ID: mdl-27311713

RESUMO

ARAP3 (Arf-GAP with Rho-GAP domain, ANK repeat, and PH domain-containing protein 3) is unique for its dual specificity GAPs (GTPase-activating protein) activity for Arf6 (ADP-ribosylation factor 6) and RhoA (Ras homolog gene family member A) regulated by phosphatidylinositol 3,4,5-trisphosphate and a small GTPase Rap1-GTP and is involved in regulation of cell shape and adhesion. However, the molecular interface between the ARAP3-RhoGAP domain and RhoA is unknown, as is the substrates specificity of the RhoGAP domain. In this study, we solved the crystal structure of RhoA in complex with the RhoGAP domain of ARAP3. The structure of the complex presented a clear interface between the RhoGAP domain and RhoA. By analyzing the crystal structure and in combination with in vitro GTPase activity assays and isothermal titration calorimetry experiments, we identified the crucial residues affecting RhoGAP activity and substrates specificity among RhoA, Rac1 (Ras-related C3 botulinum toxin substrate 1), and Cdc42 (cell division control protein 42 homolog).


Assuntos
Proteínas Adaptadoras de Transdução de Sinal/química , Proteínas Ativadoras de GTPase/química , Proteína rhoA de Ligação ao GTP/química , Fator 6 de Ribosilação do ADP , Fatores de Ribosilação do ADP/química , Fatores de Ribosilação do ADP/genética , Fatores de Ribosilação do ADP/metabolismo , Proteínas Adaptadoras de Transdução de Sinal/genética , Proteínas Adaptadoras de Transdução de Sinal/metabolismo , Cristalografia por Raios X , Proteínas Ativadoras de GTPase/genética , Proteínas Ativadoras de GTPase/metabolismo , Humanos , Fosfatos de Fosfatidilinositol/química , Fosfatos de Fosfatidilinositol/genética , Fosfatos de Fosfatidilinositol/metabolismo , Domínios Proteicos , Complexo Shelterina , Relação Estrutura-Atividade , Proteínas de Ligação a Telômeros/química , Proteínas de Ligação a Telômeros/genética , Proteínas de Ligação a Telômeros/metabolismo , Proteína rhoA de Ligação ao GTP/genética
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