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1.
Histol Histopathol ; 34(12): 1365-1375, 2019 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-31149728

RESUMO

BACKGROUND: Cytochrome c1 (CYC1) is a heme-containing subunit of mitochondria complex III and is mainly involved in cellular energy production. A recent study has demonstrated that CYC1 was overexpressed in breast carcinoma tissues and induced proliferation, migration and invasion of estrogen receptor (ER)-negative breast carcinoma cells. However, the clinical significance of CYC1 protein remains largely unclear in invasive breast carcinoma, and biological functions of CYC1 have not been reported in ER-positive breast carcinoma cells. MATERIALS AND METHODS: We immunolocalized CYC1 in 172 invasive breast carcinomas and evaluated its clinical significance according to the ER-status. Subsequently, we examined the effects of CYC1 on proliferation, glycolysis and chemosensitivity to paclitaxel, which is one of the most common chemotherapeutic agents in breast cancer, in ER-positive breast carcinoma cells (MCF7 and T47D). RESULTS: CYC1 immunoreactivity was detected in 47% of ER-positive cases and 30% of ER-negative cases. Immunohistochemical CYC1 status was inversely associated with Ki67 in ER-positive cases, and it was a significantly favorable prognostic factor for both disease-free and breast cancer-specific survival of the patients. On the other hand, no significant association was detected between CYC1 status and clinicopathological factors in ER-negative cases. In in vitro experiments, MCF7 and T47D cells transfected specific siRNA for CYC1 significantly increased cell proliferation activity, L-lactate production and cell viability after paclitaxel treatment. CONCLUSION: These results suggest that CYC1 inhibits cell proliferation, glycolytic activity and increases chemosensitivity to paclitaxel in ER-positive breast carcinoma cells and that CYC1 status is a potent favorable prognostic factor in ER-positive breast cancer patients.


Assuntos
Biomarcadores Tumorais/metabolismo , Neoplasias da Mama/metabolismo , Carcinoma/metabolismo , Citocromos c1/metabolismo , Receptor alfa de Estrogênio/metabolismo , Adulto , Idoso , Idoso de 80 Anos ou mais , Mama/patologia , Neoplasias da Mama/diagnóstico , Carcinoma/diagnóstico , Linhagem Celular Tumoral , Proliferação de Células , Sobrevivência Celular , Intervalo Livre de Doença , Feminino , Glicólise , Humanos , Antígeno Ki-67/metabolismo , Ácido Láctico/metabolismo , Células MCF-7 , Pessoa de Meia-Idade , Paclitaxel/farmacologia , Fenótipo , Prognóstico , RNA Interferente Pequeno/metabolismo , Fatores de Tempo
2.
Biochim Biophys Acta Bioenerg ; 1860(10): 148033, 2019 10 01.
Artigo em Inglês | MEDLINE | ID: mdl-31226315

RESUMO

Respiration in aerobic Actinobacteria involves a cytochrome bc1-aa3 supercomplex with a diheme cytochrome c1, first isolated from Corynebacterium glutamicum. Synthesis of a functional cytochrome c oxidase requires incorporation of CuA, CuB, heme a, and heme a3. In contrast to eukaryotes and α-proteobacteria, this process is poorly understood in Actinobacteria. Here, we analyzed the role of a Surf1 homolog of C. glutamicum in the formation of a functional bc1-aa3 supercomplex. Deletion of the surf1 gene (cg2460) in C. glutamicum caused a growth defect and cytochrome spectra revealed reduced levels of cytochrome c and a and an increased level of cytochrome d. Membranes of the Δsurf1 strain had lost the ability to oxidize the artificial electron donor N,N,N',N'-tetramethyl-p-phenylenediamine, suggesting that Surf1 is essential for the formation of a functional cytochrome aa3 oxidase. In contrast to the wild type, a bc1-aa3 supercomplex could not be purified from solubilized membranes of the Δsurf1 mutant. A transcriptome comparison revealed that the genes of the SigC regulon including those for cytochrome bd oxidase were upregulated in the Δsurf1 strain as well as the copper deprivation-inducible gene ctiP. Complementation studies showed that the Surf1 homologs of Corynebacterium diphtheriae, Mycobacterium smegmatis and Mycobacterium tuberculosis could at least partially abolish the growth defect of the C. glutamicum Δsurf1 mutant, suggesting that Surf1 is a conserved assembly factor for actinobacterial cytochrome aa3 oxidase.


Assuntos
Actinobacteria/química , Complexo IV da Cadeia de Transporte de Elétrons/biossíntese , Proteínas de Membrana/fisiologia , Proteínas Mitocondriais/fisiologia , Proteínas de Bactérias , Corynebacterium glutamicum/química , Grupo dos Citocromos c , Citocromos c1 , Complexo III da Cadeia de Transporte de Elétrons , Oxirredutases/fisiologia
3.
Gene ; 705: 77-81, 2019 Jul 15.
Artigo em Inglês | MEDLINE | ID: mdl-31009680

RESUMO

The global biodiversity of domesticated red jungle fowl (Gallus gallus) is gradually eroding by replacement with commercial poultry breeds and results loss of valuable genetic and physical traits like resistance to disease, extreme environment, etc. posing a threat to the poultry genetic resources. Very fewer reports exist on Indian poultry diversity, especially native chicken of India. Therefore, species identification and inventorying of the poultry genetic resource is indispensable. Thus, the present study aimed to characterize indigenous chicken from bio-diversity hotspot of Sunderban and Northeast India using DNA sequence based barcoding approach. A total of 15 CO1 (Cytochrome c Oxidase-I) DNA barcode of different indigenous chicken were newly sequenced along with 6 previously published sequences from our laboratory and compared with the available data of distinctive genera of Phasianidae as per the standard protocol and are identified as Gallus gallus. About 98.96% of the Phasianid birds were successfully delimitated into the respective species except for 12 congeneric pairs whose minimum interspecific K2P (Kimura 2-parameter) distance overlaps with the maximum intraspecific distance (3.9%). The least genetic divergence is observed between G. gallus and G. varius (0.013%) and highest between G. gallus and G. lafayettei (0.059%). The NJ tree showed a cohesive clustering of indigenous chicken with G. gallus and distinct with respect to all the different species under study, thereby revealing their taxonomic position except for few G. sonneratti that showed mixed clustering with G. gallus. This may be due to the genetic introgression between the species. Nevertheless, the study for the first time provided the molecular identification tag of indigenous poultry from biodiversity hotspot of East and Northeast India and will remain as a potential guide to recognize inimitable and valuable poultry genetic resources for future needs.


Assuntos
Galinhas/classificação , Galinhas/genética , Análise de Sequência de DNA/veterinária , Animais , Animais Congênicos , Biodiversidade , Citocromos c1/genética , Evolução Molecular , Variação Genética , Índia , Filogenia
4.
Planta ; 249(5): 1477-1485, 2019 May.
Artigo em Inglês | MEDLINE | ID: mdl-30694389

RESUMO

MAIN CONCLUSION: The gene GRMZM2G318346 which encodes a cytochrome b-c1 complex subunit 7 is associated with variation in strength of the hypersensitive response in maize. We previously identified a QTL at 3,545,354 bp (B73 reference genome V2) on maize chromosome 5 associated with variation in the hypersensitive response (HR) conferred by the autoactive R-gene Rp1-D21 (Olukolu et al. in PLoS Genet 10:e1004562 2014). In this study, we show that a gene at this locus, GRMZM2G318346 which encodes a cytochrome b-c1 complex subunit seven (ZmQCR7), an important part of the mitochondrial electron transport chain, can suppress HR mediated by Rp1-D21 in a transient expression assay. ZmQCR7 alleles from two maize lines, W22 and B73 differ for the encoded proteins at just two sites, amino acid 27 (threonine and alanine in B73 and W22, respectively) and amino acid 109 (asparagine and serine), however, the B73 allele is much more effective at suppressing HR. We show that variation at amino acid 27 controlled this variation in HR-suppressing effects. We furthermore demonstrate that the B73 allele of ZmQCR7 can suppress HR induced by RPM1(D505 V), another autoactive R-gene, and that Arabidopsis homologs of ZmQCR7 can also suppress NLR-induced HR. The implications of these findings are discussed.


Assuntos
Citocromos b/metabolismo , Citocromos c1/metabolismo , Doenças das Plantas/microbiologia , Proteínas de Plantas/metabolismo , Zea mays/metabolismo , Citocromos b/genética , Citocromos c1/genética , Resistência à Doença/genética , Resistência à Doença/fisiologia , Proteínas de Plantas/genética , Locos de Características Quantitativas/genética , Espécies Reativas de Oxigênio/metabolismo , Zea mays/genética
5.
Int J Mol Med ; 42(6): 3291-3299, 2018 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-30280186

RESUMO

Oral squamous cell carcinoma (OSCC) is a major cancer type in the head and neck region. Recent studies have reported a marked rise in the incidence of OSCC. The present study was performed to better understand the roles that long non­coding RNAs (lncRNAs) serve in OSCC carcinogenesis. The levels of the lncRNA C5orf66 antisense RNA 1 (C5orf66­AS1) and of cytochrome c1 (CYC1) in OSCC tissues and cells were measured through reverse transcription­quantitative polymerase chain reaction. In addition, the levels of associated proteins were analyzed by western blotting, while MTT assay was used to detect the cell proliferation ability. Wound healing and transwell assays were also used to detect the migration and invasion abilities of OSCC cells in the experimental groups, while flow cytometry was applied to analyze cell apoptosis. The findings revealed that the expression of lncRNA C5orf66­AS1 in OSCC tissues and cells was significantly decreased. Overexpression of lncRNA C5orf66­AS1 significantly inhibited the proliferation, invasion and migration ability of OSCC cells, and promoted cell apoptosis, while lncRNA C5orf66­AS1 downregulation presented the opposite effects. In addition, it was observed that CYC1 was upregulated in OSCC tissues and cells, and was negatively regulated by lncRNA C5orf66­AS1. Notably, CYC1 silencing markedly eliminated the effects of lncRNA C5orf66­AS1 downregulation on OSCC cells. Taken together, these findings indicated that lncRNA C5orf66­AS1 may prevent OSCC progression by inhibiting OSCC cell growth and metastasis via the regulation of CYC1 expression.


Assuntos
Carcinoma de Células Escamosas/metabolismo , Neoplasias Bucais/metabolismo , RNA Longo não Codificante/metabolismo , Apoptose/genética , Apoptose/fisiologia , Western Blotting , Carcinoma de Células Escamosas/genética , Linhagem Celular , Linhagem Celular Tumoral , Movimento Celular/genética , Movimento Celular/fisiologia , Proliferação de Células/genética , Proliferação de Células/fisiologia , Citocromos c1/genética , Citocromos c1/metabolismo , Regulação Neoplásica da Expressão Gênica/genética , Regulação Neoplásica da Expressão Gênica/fisiologia , Humanos , Neoplasias Bucais/genética , RNA Longo não Codificante/genética , Reação em Cadeia da Polimerase Via Transcriptase Reversa
6.
Chem Commun (Camb) ; 54(89): 12630-12633, 2018 Nov 06.
Artigo em Inglês | MEDLINE | ID: mdl-30351312

RESUMO

Spectral overlap makes it difficult to use NMR for mapping the conformational profile of heterogeneous conformational ensembles of macromolecules. Here, we apply a 1H-14N HSQC experiment to monitor the alkaline conformational transitions of yeast iso-1 cytochrome c (ycyt c) at natural isotopic abundance. Trimethylated Lys72 of ycyt c is selectively detected by a 1H-14N HSQC experiment, and used as a probe to trace conformational transitions of ycyt c under alkaline conditions. It was found that at least four different conformers of ycyt c coexisted under alkaline conditions. Besides the native structure, Lys73 or Lys79 coordinated conformers and a partially unfolded state with exposed heme were observed. These results indicate that the method is powerful at simplifying spectra of a trimethylated protein, which makes it possible to study complex conformational transitions of naturally extracted or chemically modified trimethylated protein at natural isotopic abundance.


Assuntos
Álcalis/metabolismo , Citocromos c1/metabolismo , Lisina/análogos & derivados , Sondas Moleculares/metabolismo , Saccharomyces cerevisiae/química , Álcalis/química , Citocromos c1/química , Lisina/química , Lisina/metabolismo , Espectroscopia de Ressonância Magnética , Sondas Moleculares/química , Nitrogênio/química , Prótons , Saccharomyces cerevisiae/metabolismo
7.
J Biol Chem ; 293(40): 15628-15640, 2018 10 05.
Artigo em Inglês | MEDLINE | ID: mdl-30154248

RESUMO

Aerobic respiration in Corynebacterium glutamicum involves a cytochrome bc 1-aa 3 supercomplex with a diheme cytochrome c 1, which is the only c-type cytochrome in this species. This organization is considered as typical for aerobic Actinobacteria. Whereas the biogenesis of heme-copper type oxidases like cytochrome aa 3 has been studied extensively in α-proteobacteria, yeast, and mammals, nothing is known about this process in Actinobacteria. Here, we searched for assembly proteins of the supercomplex by identifying the copper-deprivation stimulon, which might include proteins that insert copper into cytochrome aa 3 Using gene expression profiling, we found two copper starvation-induced proteins for supercomplex formation. The Cg2699 protein, named CtiP, contained 16 predicted transmembrane helices, and its sequence was similar to that of the copper importer CopD of Pseudomonas syringae in the N-terminal half and to the cytochrome oxidase maturation protein CtaG of Bacillus subtilis in its C-terminal half. CtiP deletion caused a growth defect similar to that produced by deletion of subunit I of cytochrome aa 3, increased copper tolerance, triggered expression of the copper-deprivation stimulon under copper sufficiency, and prevented co-purification of the supercomplex subunits. The secreted Cg1884 protein, named CopC, had a C-terminal transmembrane helix and contained a Cu(II)-binding motif. Its absence caused a conditional growth defect, increased copper tolerance, and also prevented co-purification of the supercomplex subunits. CtiP and CopC are conserved among aerobic Actinobacteria, and we propose a model of their functions in cytochrome aa 3 biogenesis. Furthermore, we found that the copper-deprivation response involves additional regulators besides the ECF sigma factor SigC.


Assuntos
Cobre/metabolismo , Corynebacterium glutamicum/genética , Citocromos c1/metabolismo , Complexo III da Cadeia de Transporte de Elétrons/metabolismo , Complexo IV da Cadeia de Transporte de Elétrons/metabolismo , Regulação Bacteriana da Expressão Gênica , Aerobiose/genética , Sequência de Aminoácidos , Bacillus subtilis/enzimologia , Bacillus subtilis/genética , Proteínas de Bactérias/genética , Proteínas de Bactérias/metabolismo , Cátions Bivalentes , Corynebacterium glutamicum/enzimologia , Citocromos c1/genética , Proteínas de Ligação a DNA/genética , Proteínas de Ligação a DNA/metabolismo , Complexo III da Cadeia de Transporte de Elétrons/genética , Complexo IV da Cadeia de Transporte de Elétrons/genética , Escherichia coli/enzimologia , Escherichia coli/genética , Multimerização Proteica , Pseudomonas syringae/enzimologia , Pseudomonas syringae/genética , Fator sigma/genética , Fator sigma/metabolismo
8.
Biochim Biophys Acta Bioenerg ; 1859(9): 754-761, 2018 09.
Artigo em Inglês | MEDLINE | ID: mdl-29705394

RESUMO

Transfer of electron from quinol to cytochrome c is an integral part of catalytic cycle of cytochrome bc1. It is a multi-step reaction involving: i) electron transfer from quinol bound at the catalytic Qo site to the Rieske iron-sulfur ([2Fe-2S]) cluster, ii) large-scale movement of a domain containing [2Fe-2S] cluster (ISP-HD) towards cytochrome c1, iii) reduction of cytochrome c1 by reduced [2Fe-2S] cluster, iv) reduction of cytochrome c by cytochrome c1. In this work, to examine this multi-step reaction we introduced various types of barriers for electron transfer within the chain of [2Fe-2S] cluster, cytochrome c1 and cytochrome c. The barriers included: impediment in the motion of ISP-HD, uphill electron transfer from [2Fe-2S] cluster to heme c1 of cytochrome c1, and impediment in the catalytic quinol oxidation. The barriers were introduced separately or in various combinations and their effects on enzymatic activity of cytochrome bc1 were compared. This analysis revealed significant degree of functional flexibility allowing the cofactor chains to accommodate certain structural and/or redox potential changes without losing overall electron and proton transfers capabilities. In some cases inhibitory effects compensated one another to improve/restore the function. The results support an equilibrium model in which a random oscillation of ISP-HD between the Qo site and cytochrome c1 helps maintaining redox equilibrium between all cofactors of the chain. We propose a new concept in which independence of the dynamics of the Qo site substrate and the motion of ISP-HD is one of the elements supporting this equilibrium and also is a potential factor limiting the overall catalytic rate.


Assuntos
Citocromos b/química , Citocromos c1/metabolismo , Citocromos c/metabolismo , Complexo III da Cadeia de Transporte de Elétrons/química , Hidroquinonas/química , Proteínas com Ferro-Enxofre/química , Mutação , Sítios de Ligação , Catálise , Domínio Catalítico , Citocromos b/genética , Citocromos b/metabolismo , Citocromos c/química , Citocromos c1/química , Transporte de Elétrons , Complexo III da Cadeia de Transporte de Elétrons/genética , Complexo III da Cadeia de Transporte de Elétrons/metabolismo , Heme/química , Heme/metabolismo , Proteínas com Ferro-Enxofre/genética , Proteínas com Ferro-Enxofre/metabolismo , Modelos Moleculares , Oxirredução , Conformação Proteica , Rhodobacter capsulatus/crescimento & desenvolvimento , Rhodobacter capsulatus/metabolismo
9.
J Biol Chem ; 293(15): 5585-5599, 2018 04 13.
Artigo em Inglês | MEDLINE | ID: mdl-29475949

RESUMO

Cytochrome b (Cytb) is the only mitochondrial encoded subunit from the bc1 complex. Cbp3 and Cbp6 are chaperones necessary for translation of the COB mRNA and Cytb hemylation. Here we demonstrate that their role in translation is dispensable in some laboratory strains, whereas their role in Cytb hemylation seems to be universally conserved. BY4742 yeast requires Cbp3 and Cbp6 for efficient COB mRNA translation, whereas the D273-10b strain synthesizes Cytb at wildtype levels in the absence of Cbp3 and Cbp6. Steady-state levels of Cytb are close to wildtype in mutant D273-10b cells, and Cytb forms non-functional, supercomplex-like species with cytochrome c oxidase, in which at least core 1, cytochrome c1, and Rieske iron-sulfur subunits are present. We demonstrated that Cbp3 interacts with the mitochondrial ribosome and with the COB mRNA in both BY4742 and D273-10b strains. The polymorphism(s) causing the differential function of Cbp3, Cbp6, and the assembly feedback regulation of Cytb synthesis is of nuclear origin rather than mitochondrial, and Smt1, a COB mRNA-binding protein, does not seem to be involved in the observed differential phenotype. Our results indicate that the essential role of Cbp3 and Cbp6 is to assist Cytb hemylation and demonstrate that in the absence of heme b, Cytb can form non-functional supercomplexes with cytochrome c oxidase. Our observations support that an additional protein or proteins are involved in Cytb synthesis in some yeast strains.


Assuntos
Citocromos b/biossíntese , Proteínas de Membrana/metabolismo , Mitocôndrias/metabolismo , Proteínas Mitocondriais/biossíntese , Chaperonas Moleculares/metabolismo , Biossíntese de Proteínas , Proteínas de Saccharomyces cerevisiae/metabolismo , Saccharomyces cerevisiae/metabolismo , Citocromos b/genética , Citocromos c1/genética , Citocromos c1/metabolismo , Proteínas de Membrana/genética , Metiltransferases/genética , Metiltransferases/metabolismo , Mitocôndrias/genética , Proteínas Mitocondriais/genética , Proteínas Mitocondriais/metabolismo , Chaperonas Moleculares/genética , Saccharomyces cerevisiae/genética , Proteínas de Saccharomyces cerevisiae/genética
10.
Genes Genet Syst ; 92(4): 197-203, 2018 Feb 10.
Artigo em Inglês | MEDLINE | ID: mdl-28674276

RESUMO

The brown hagfish (Eptatretus atami) is one of several known hagfish species occurring in Japanese coastal waters. To date, there has been no research studying genetic polymorphisms in the species. In the present study, we analyzed differences in nucleotide sequences between two populations: one from Suruga Bay on the Pacific coast of Honshu, Japan, and the other from the Sea of Japan, off Akita on the northwest coast of Honshu. We sequenced part of the cytochrome oxidase subunit 1 gene (COX1) from the mitochondrial genome, and three G protein-coupled receptor genes from the nuclear genome. Phylogenetic networks of all four genes showed divergence between the two populations. Further, comparison of the COX1 data using a phylogenetic tree for a range of hagfish species indicated clear differences between the populations, suggesting that they differ at the species level. The numbers of their teeth, in particular of fused cusps (anterior/posterior multicusps), also supported these findings. Individuals of the Suruga Bay population had 3/3 fused cusps, as described for E. atami, whereas individuals of the Akita population had 3/2 fused cusps. These results suggest that the brown hagfish from the Sea of Japan, off the northwest coast of Honshu, is a distinct species from E. atami.


Assuntos
Citocromos c1/genética , Feiticeiras (Peixe)/genética , Animais , Sequência de Bases/genética , DNA Mitocondrial/genética , Genoma/genética , Japão , Filogenia
11.
Korean J Parasitol ; 55(3): 319-325, 2017 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-28719957

RESUMO

We described 4 human infection cases of zoonotic fish-tapeworm, Diphyllobothrium nihonkaiense, identified with morphological and molecular characters and briefly reviewed Chinese cases in consideration of it as an emerging parasitic disease in China. The scolex and mature and gravid proglottids of some cases were seen, a rosette-shaped uterus was observed in the middle of the mature and gravid proglottids, and the diphyllobothriid eggs were yellowish-brown in color and displayed a small knob or abopercular protuberance on the opposite end of a lid-like opening. The average size of the eggs was recorded as 62-67×42-45 µm. The parasitic materials gathered from 4 human cases were morphologically identified as belonging to the genera Diphyllobothrium and Adenocephalus. The phylogenetic analysis based on the nucleotide sequences of cytochrome c oxidase subunit 1 gene of the etiologic agents confirmed that the 4 cases were D. nihonkaiense infection. The finding of 4 additional D. nihonkaiense cases suggests that D. nihonkaiense might be a major causative species of human diphyllobothriasis in China. A combined morphological and molecular analysis is the main method to confirm D. nihonkaiense infection.


Assuntos
Difilobotríase/diagnóstico , Difilobotríase/parasitologia , Diphyllobothrium/genética , Diphyllobothrium/isolamento & purificação , Adulto , Animais , Sequência de Bases/genética , China , Citocromos c1/genética , Diphyllobothrium/anatomia & histologia , Diphyllobothrium/classificação , Feminino , Humanos , Masculino , Contagem de Ovos de Parasitas , Filogenia
12.
Cell Physiol Biochem ; 41(5): 1935-1946, 2017.
Artigo em Inglês | MEDLINE | ID: mdl-28391262

RESUMO

AIM: Osteosarcoma (OS) is an aggressive bone malignancy that affects rapidly growing bones and is associated with a poor prognosis. Our previous study showed that cytochrome c1 (CYC1), a subunit of the cytochrome bc1 complex (complex III) of the mitochondrial electron chain, is overexpressed in human OS tissues and cell lines and its silencing induces apoptosis in vitro and inhibits tumor growth in vivo. Here, we investigated the mechanism underlying the modulation of CYC1 expression in OS and its role in the resistance of OS to apoptosis. METHODS: qRT-PCR, luciferase reporter assay, western blotting, fow cytometry, and animal experiments were performed in this study. RESULTS: MicroRNA (miR)-661 was identified as a downregulated miRNA in OS tissues and cells and shown to directly target CYC1. Ectopically expressed miR-661 inhibited OS cell growth, promoted apoptosis, and reduced the activity of mitochondrial complex III. miR-661 overexpression enhanced TRAIL or STS induced apoptosis and promoted the release of cytochrome c into the cytosol, which induced caspase-9 activation, and these effects were abolished by a caspase-3 inhibitor. Overexpression of CYC1 rescued the effects of miR-661 on sensitizing OS cells to TRAIL or STS induced apoptosis, indicating that the antitumor effect of miR-661 is mediated by the downregulation of CYC1. In vivo, miR-661 overexpression sensitized tumors to TRAIL or STS induced apoptosis in a xenograft mouse model, and these effects were attenuated by co-expression of CYC1. CONCLUSION: Taken together, our results indicate that miR-661 plays a tumor suppressor role in OS mediated by the downregulation of CYC1, suggesting a potential mechanism underlying cell death resistance in OS.


Assuntos
Apoptose , Neoplasias Ósseas/metabolismo , Citocromos c1/biossíntese , Regulação Enzimológica da Expressão Gênica , Regulação Neoplásica da Expressão Gênica , Genes Supressores de Tumor , MicroRNAs/biossíntese , Proteínas de Neoplasias/metabolismo , Osteossarcoma/metabolismo , RNA Neoplásico/biossíntese , Esteril-Sulfatase/metabolismo , Ligante Indutor de Apoptose Relacionado a TNF/metabolismo , Animais , Neoplasias Ósseas/genética , Neoplasias Ósseas/patologia , Citocromos c1/genética , Feminino , Humanos , Masculino , Camundongos , Camundongos Nus , MicroRNAs/genética , Proteínas de Neoplasias/genética , Osteossarcoma/genética , Osteossarcoma/patologia , RNA Neoplásico/genética , Esteril-Sulfatase/genética , Ligante Indutor de Apoptose Relacionado a TNF/genética , Células Tumorais Cultivadas
13.
Cancer Sci ; 108(7): 1510-1519, 2017 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-28394473

RESUMO

It is well known that comedo necrosis is closely associated with an aggressive phenotype of ductal carcinoma in situ (DCIS) of human breast, but its molecular mechanisms remain largely unclear. Therefore, in this study, we first examined the gene expression profile of comedo DCIS based on microarray data and identified CYC1 as a gene associated with comedo necrosis. Cytochrome c1 (CYC1) is a subunit of complex III in the mitochondrial oxidative phosphorylation that is involved in energy production. However, the significance of CYC1 has not yet been examined in DCIS. We therefore immunolocalized CYC1 in 47 DCIS cases. CYC1 immunoreactivity was detected in 40% of DCIS cases, and the immunohistochemical CYC1 status was significantly associated with tumor size, nuclear grade, comedo necrosis, van Nuys classification, and Ki-67 labeling index. Subsequent in vitro studies indicated that CYC1 was significantly associated with mitochondrial membrane potential in MCF10DCIS.com DCIS cells. Moreover, CYC1 significantly promoted proliferation activity of MCF10DCIS.com cells and the cells transfected with CYC1 siRNA decreased pro-apoptotic caspase 3 activity under hypoxic or anoxic conditions. Considering that the center of DCIS is poorly oxygenated, these results indicate that CYC1 plays important roles in cell proliferation and comedo necrosis through the elevated oxidative phosphorylation activity in human DCIS.


Assuntos
Neoplasias da Mama/patologia , Carcinoma Intraductal não Infiltrante/patologia , Citocromos c1/metabolismo , Adulto , Idoso , Idoso de 80 Anos ou mais , Neoplasias da Mama/metabolismo , Carcinoma Intraductal não Infiltrante/metabolismo , Feminino , Humanos , Immunoblotting , Imuno-Histoquímica , Microdissecção e Captura a Laser , Pessoa de Meia-Idade , Necrose , Análise de Sequência com Séries de Oligonucleotídeos , Reação em Cadeia da Polimerase em Tempo Real , Transcriptoma
14.
Mol Microbiol ; 105(1): 127-138, 2017 07.
Artigo em Inglês | MEDLINE | ID: mdl-28388834

RESUMO

Members of the multihaem cytochrome c family such as pentahaem cytochrome c nitrite reductase (NrfA) or octahaem hydroxylamine oxidoreductase (Hao) are involved in various microbial respiratory electron transport chains. Some members of the Hao subfamily, here called εHao proteins, have been predicted from the genomes of nitrate/nitrite-ammonifying bacteria that usually lack NrfA. Here, εHao proteins from the host-associated Epsilonproteobacteria Campylobacter fetus and Campylobacter curvus and the deep-sea hydrothermal vent bacteria Caminibacter mediatlanticus and Nautilia profundicola were purified as εHao-maltose binding protein fusions produced in Wolinella succinogenes. All four proteins were able to catalyze reduction of nitrite (yielding ammonium) and hydroxylamine whereas hydroxylamine oxidation was negligible. The introduction of a tyrosine residue at a position known to cause covalent trimerization of Hao proteins did neither stimulate hydroxylamine oxidation nor generate the Hao-typical absorbance maximum at 460 nm. In most cases, the εHao-encoding gene haoA was situated downstream of haoC, which predicts a tetrahaem cytochrome c of the NapC/NrfH family. This suggested the formation of a membrane-bound HaoCA assembly reminiscent of the menaquinol-oxidizing NrfHA complex. The results indicate that εHao proteins form a subfamily of ammonifying cytochrome c nitrite reductases that represents a 'missing link' in the evolution of NrfA and Hao enzymes.


Assuntos
Citocromos c/metabolismo , Oxirredutases/metabolismo , Proteínas de Bactérias/metabolismo , Grupo dos Citocromos c , Citocromos a1/metabolismo , Citocromos c1/metabolismo , Epsilonproteobacteria/genética , Epsilonproteobacteria/metabolismo , Nitrato Redutases/metabolismo , Nitritos/metabolismo , Oxirredução , Oxirredutases/genética , Wolinella/genética
15.
Gene ; 605: 12-19, 2017 Mar 20.
Artigo em Inglês | MEDLINE | ID: mdl-28104086

RESUMO

The genus Triplophysa is the largest and most difficult to identity morphologically fish group of superfamily Cobitoidea with 140 currently valid species, and is mainly distributed in the Qinghai-Tibetan Plateau (QTP) and adjacent regions. Most species within this genus possess highly similar morphological characteristics for adaption to the highland environment and are very difficult to be identified only based on morphology. The traditional species identification, mainly based on external morphological diagnostic characters, leads to inconsistent results in many cases. Herein, we provided a molecular method based on mitochondrial cytochrome c subunit I (COI) for the identification of Triplophysa fishes. Thirty-three Triplophysa species, 244 individuals, were used to determine whether barcoding was effective in discriminating species for this genus. The mean intraspecific and interspecific K2P distances ranged from 0 to 14.9% (mean, 2.9%) and 0 to 23.4% (mean, 9.7%), respectively. The tree-based analysis displayed most of species formed discrete clusters with strong bootstrap support values (>90%). The results showed that most of Triplophysa species could be identified by DNA barcode and indicated DNA barcode could be used as a molecular marker for these species.


Assuntos
Cipriniformes/genética , Citocromos c1/genética , DNA/genética , Proteínas de Peixes/genética , Filogenia , Animais , Artefatos , Cipriniformes/classificação , Código de Barras de DNA Taxonômico/métodos , Expressão Gênica , Variação Genética , Filogeografia , Tibet
16.
Sci Rep ; 6: 37456, 2016 11 18.
Artigo em Inglês | MEDLINE | ID: mdl-27857202

RESUMO

Shewanella, a group of ubiquitous bacteria renowned for respiratory versatility, thrive in environments where various electron acceptors (EAs) of different chemical and physiological characteristics coexist. Despite being extensively studied, we still know surprisingly little about strategies by which multiple EAs and their interaction define ecophysiology of these bacteria. Previously, we showed that nitrite inhibits growth of the genus representative Shewanella oneidensis on fumarate and presumably some other CymA (quinol dehydrogenase)-dependent EAs by reducing cAMP production, which in turn leads to lowered expression of nitrite and fumarate reductases. In this study, we demonstrated that inhibition of fumarate growth by nitrite is also attributable to overproduction of NapB, the cytochrome c subunit of nitrate reductase. Further investigations revealed that excessive NapB per se inhibits growth on all EAs tested, including oxygen. When overproduced, NapB acts as an electron shuttle to dissipate electrons of the quinol pool, likely to extracellullar EAs, because the Mtr system, the major electron transport pathway for extracellular electron transport, is implicated. The study not only sheds light on mechanisms by which certain EAs, especially toxic ones, impact the bacterial ecophysiology, but also provides new insights into how electron shuttle c-type cytochromes regulate multi-branched respiratory networks.


Assuntos
Citocromos a1/genética , Citocromos c1/genética , Nitrato Redutases/genética , Oxirredução/efeitos dos fármacos , Shewanella/genética , Transporte de Elétrons/efeitos dos fármacos , Elétrons , Fumaratos/química , Fumaratos/metabolismo , Hidroquinonas/química , Hidroquinonas/metabolismo , Nitritos/toxicidade , Shewanella/efeitos dos fármacos , Shewanella/crescimento & desenvolvimento
17.
FEBS J ; 283(20): 3807-3820, 2016 10.
Artigo em Inglês | MEDLINE | ID: mdl-27586496

RESUMO

The Crenarchaeon Ignicoccus hospitalis lives in symbiosis with Nanoarchaeum equitans providing essential cell components and nutrients to its symbiont. Ignicoccus hospitalis shows an intriguing morphology that points toward an evolutionary role in driving compartmentalization. Therefore, the bioenergetics of this archaeal host-symbiont system remains a pressing question. To date, the only electron acceptor described for I. hospitalis is elemental sulfur, but the organism comprises genes that encode for enzymes involved in nitrogen metabolism, e.g., one nitrate reductase and two octaheme cytochrome c, Igni_0955 (IhOCC) and Igni_1359. Herein, we detail functional and structural studies of the highly abundant IhOCC, including an X-ray crystal structure at 1.7 Å resolution, the first three-dimensional structure of an archaeal OCC. The trimeric IhOCC is membrane associated and exhibits significant structural and functional differences to previously characterized homologs within the hydroxylamine oxidoreductases (HAOs) and octaheme cytochrome c nitrite reductases (ONRs). The positions and spatial arrangement of the eight hemes are highly conserved, but the axial ligands of the individual hemes 3, 6 and 7 and the protein environment of the active site show significant differences. Most notably, the active site heme 4 lacks porphyrin-tyrosine cross-links present in the HAO family. We show that IhOCC efficiently reduces nitrite and hydroxylamine, with possible relevance to detoxification or energy conservation. DATABASE: Structural data are available in the Protein Data Bank under the accession number 4QO5.


Assuntos
Proteínas Arqueais/química , Citocromos c/química , Desulfurococcaceae/química , Proteínas Arqueais/genética , Proteínas Arqueais/metabolismo , Sítios de Ligação , Sequência Conservada , Cristalografia por Raios X , Citocromos a1/química , Citocromos a1/genética , Citocromos a1/metabolismo , Citocromos c/genética , Citocromos c/metabolismo , Citocromos c1/química , Citocromos c1/genética , Citocromos c1/metabolismo , Desulfurococcaceae/genética , Desulfurococcaceae/metabolismo , Evolução Molecular , Genes Arqueais , Heme/química , Modelos Moleculares , Nitrato Redutases/química , Nitrato Redutases/genética , Nitrato Redutases/metabolismo , Estrutura Quaternária de Proteína , Subunidades Proteicas , Eletricidade Estática
18.
Mol Biochem Parasitol ; 210(1-2): 32-36, 2016.
Artigo em Inglês | MEDLINE | ID: mdl-27520480

RESUMO

Malaria parasites possess a de novo heme synthetic pathway. Interestingly, this pathway is dispensable during the blood stages of development in mammalian hosts. The assembly of the two most important hemeproteins, cytochromes c and c1, is mediated by cytochrome heme lyase enzymes. Plasmodium spp. possess two cytochrome heme lyases encoded by separate genes. Given the redundancy of heme synthesis, we sought to determine if heme lyase function also exhibits redundancy. To answer this question, we performed gene knockout experiments. We found that the PBANKA_143950 and PBANKA_0602600 Plasmodium berghei genes encoding cytochrome c (Pbcchl) and cytochrome c1 (Pbcc1hl) heme lyases, respectively, can only be disrupted when a complementary gene is present. In contrast, four genes in the de novo heme synthesis pathway can be disrupted without complementation. This work provides evidence that Pbcchl and Pbcc1hl are both essential and thus may be antimalarial targets.


Assuntos
Citocromos c1/metabolismo , Citocromos c/metabolismo , Heme/metabolismo , Plasmodium berghei/fisiologia , Citocromos c/genética , Citocromos c1/genética , Expressão Gênica , Regulação da Expressão Gênica , Marcação de Genes , Genes Essenciais , Vetores Genéticos/genética , Mitocôndrias/genética , Mitocôndrias/metabolismo
19.
Dis Markers ; 2016: 3528064, 2016.
Artigo em Inglês | MEDLINE | ID: mdl-27239088

RESUMO

Cytochrome c-1 (CYC1) is an important subunit of mitochondrial complex III. However, its role in tumor progression is unclear. We found that CYC1 was upregulated in breast tumor tissues, especially in tissues with lymph node metastasis. And higher expression of CYC1 correlates with poor prognosis in breast cancer patients using online databases and tools. Then we confirmed that CYC1 contributed to metastasis and proliferation in two highly metastatic human breast cancer cell lines. Digging into the biological function of CYC1, we found the activity of mitochondrial complex III decreased due to silencing CYC1. Then the ratio of AMP to ATP increased and AMPK was activated. Analyzing units of other mitochondrial complexes, we did not find knockdown of CYC1 expression reduced expression of any other unit of OXPHOS. We concluded that CYC1 promoted tumor metastasis via suppressing activation of AMPK and contributed to tumor growth via facilitating production of ATP. Our results indicated that CYC1 plays crucial roles in breast cancer progression and might be a predictive factor assisting future patient diagnosis.


Assuntos
Biomarcadores Tumorais/metabolismo , Neoplasias da Mama/metabolismo , Carcinoma Ductal/metabolismo , Citocromos c1/metabolismo , Proteínas Quinases Ativadas por AMP/metabolismo , Trifosfato de Adenosina/metabolismo , Adulto , Biomarcadores Tumorais/genética , Neoplasias da Mama/patologia , Carcinoma Ductal/patologia , Linhagem Celular Tumoral , Proliferação de Células , Citocromos c1/genética , Feminino , Humanos , Pessoa de Meia-Idade , Metástase Neoplásica , Fosforilação Oxidativa
20.
J Neurochem ; 138(1): 53-9, 2016 07.
Artigo em Inglês | MEDLINE | ID: mdl-27062510

RESUMO

The RNA integrity number (RIN) is often considered to be a critical measure of the quality of postmortem human brains. However, it has been suggested that RINs do not necessarily reflect the availability of intact mRNA. Using the Agilent bioanalyzer and qRT-PCR, we explored whether RINs provide a meaningful way of assessing mRNA degradation and integrity in human brain samples by evaluating the expression of 3'-5' mRNA sequences of the cytochrome C-1 (CYC1) gene. Analysis of electropherograms showed that RINs were not consistently correlated with RNA or cDNA profiles and appeared to be poor predictors of overall cDNA quality. Cycle thresholds from qRT-PCR analysis to quantify the amount of CYC1 mRNA revealed positive correlations of RINs with amplification of full-length transcripts, despite the variable degree of linear degradation along the 3'-5' sequence. These data demonstrate that in postmortem human brain tissue the RIN is an indicator of mRNA quantity independent of degradation, but does not predict mRNA integrity, suggesting that RINs provide an incomplete measure of brain tissue quality. Quality assessment of postmortem human brains by RNA integrity numbers (RINs) may be misleading, as they do not measure intact mRNAs. We show that the RIN is an indicator of mRNA quantity independent of degradation, but does not predict mRNA integrity, suggesting that RINs provide an incomplete measure of brain tissue quality. Our results resolve controversial assumption on interpreting quality assessments of human postmortem brains by RINs.


Assuntos
Encéfalo/metabolismo , Encéfalo/patologia , Citocromos c1/genética , RNA/metabolismo , Adolescente , Adulto , Idoso , Idoso de 80 Anos ou mais , Células Cultivadas , Fibroblastos , Perfilação da Expressão Gênica , Humanos , Transtornos Mentais/patologia , Pessoa de Meia-Idade , Doenças Neurodegenerativas/patologia , Mudanças Depois da Morte , Valor Preditivo dos Testes , Estabilidade de RNA/fisiologia , RNA Mensageiro/metabolismo , Adulto Jovem
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