RESUMO
LMNA gene mutation can cause muscular dystrophy, and post-translational modification plays a critical role in regulating its function. Here, we identify that lamin A is palmitoylated at cysteine 522, 588, and 591 residues, which are reversely catalyzed by palmitoyltransferase zinc finger DHHC-type palmitoyltransferase 5 (ZDHHC5) and depalmitoylase α/ß hydrolase domain 7 (ABHD7). Furthermore, the metabolite lactate promotes palmitoylation of lamin A by inhibiting the interaction between it and ABHD7. Interestingly, low-level palmitoylation of lamin A promotes, whereas high-level palmitoylation of lamin A inhibits, murine myoblast differentiation. Together, these observations suggest that ABHD7-mediated depalmitoylation of lamin A controls myoblast differentiation.
Assuntos
Lamina Tipo A , Distrofias Musculares , Animais , Camundongos , Diferenciação Celular , Lamina Tipo A/metabolismo , Distrofias Musculares/genética , Mioblastos/metabolismo , Processamento de Proteína Pós-TraducionalRESUMO
Epithelial ovarian cancer (EOC) exhibits strong dependency on the tricarboxylic acid (TCA) cycle and oxidative phosphorylation to fuel anabolic process. Here, we show that malate dehydrogenase 2 (MDH2), a key enzyme of the TCA cycle, is palmitoylated at cysteine 138 (C138) residue, resulting in increased activity of MDH2. We next identify that ZDHHC18 acts as a palmitoyltransferase of MDH2. Glutamine deprivation enhances MDH2 palmitoylation by increasing the binding between ZDHHC18 and MDH2. MDH2 silencing represses mitochondrial respiration as well as ovarian cancer cell proliferation both in vitro and in vivo. Intriguingly, re-expression of wild-type MDH2, but not its palmitoylation-deficient C138S mutant, sustains mitochondrial respiration and restores the growth as well as clonogenic capability of ovarian cancer cells. Notably, MDH2 palmitoylation level is elevated in clinical cancer samples from patients with high-grade serous ovarian cancer. These observations suggest that MDH2 palmitoylation catalyzed by ZDHHC18 sustains mitochondrial respiration and promotes the malignancy of ovarian cancer, yielding possibilities of targeting ZDHHC18-mediated MDH2 palmitoylation in the treatment of EOC.
Assuntos
Malato Desidrogenase , Neoplasias Ovarianas , Carcinoma Epitelial do Ovário , Linhagem Celular Tumoral , Cisteína , Feminino , Glutamina , Humanos , Lipoilação , Malato Desidrogenase/química , Malato Desidrogenase/metabolismo , Respiração , Ácidos TricarboxílicosRESUMO
Colorectal cancer (CRC) represents the third most common cancer in males and second in females worldwide. Here, we performed a quantitative 8-plex iTRAQ proteomics analysis of the secreted proteins from five colonic fibroblast cultures and three colon cancer epithelial cell lines. We identified 1114 proteins at 0% FDR, including 587 potential secreted proteins. We further recognized 116 fibroblast-enriched proteins which were significantly associated with cell movement, angiogenesis, proliferation and wound healing, and 44 epithelial cell-enriched proteins. By interrogation of Oncomine database, we found that 20 and 8 fibroblast-enriched proteins were up- and downregulated in CRC, respectively. Western blots confirmed the fibroblast-specific secretion of filamin C, COL6A3, COL4A1 and spondin-2. Upregulated mRNA and stroma expression of COL6A3 in CRC, which were revealed by Oncomine analyses and tissue-microarray-immunohistochemistry, indicated poor prognosis. COL6A3 expression was significantly associated with Dukes stage, T stage, stage, recurrence and smoking status. Circulating plasma COL6A3 in CRC patients was upregulated significantly comparing with healthy peoples. Receiver operating characteristic curve analysis revealed that COL6A3 has better predictive performance for CRC with an area under the curve of 0.885 and the best sensitivity/specificity of 92.9%/81.3%. Thus we demonstrated that COL6A3 was a potential diagnosis and prognosis marker of CRC.
Assuntos
Biomarcadores Tumorais/metabolismo , Colágeno Tipo VI/metabolismo , Neoplasias Colorretais/metabolismo , Proteômica/métodos , Adulto , Idoso , Idoso de 80 Anos ou mais , Biomarcadores Tumorais/sangue , Biomarcadores Tumorais/genética , Western Blotting , Linhagem Celular Tumoral , Células Cultivadas , Colágeno Tipo VI/sangue , Colágeno Tipo VI/genética , Neoplasias Colorretais/sangue , Neoplasias Colorretais/genética , Feminino , Fibroblastos/metabolismo , Regulação Neoplásica da Expressão Gênica , Células HT29 , Humanos , Imuno-Histoquímica , Masculino , Pessoa de Meia-Idade , Prognóstico , RNA Mensageiro/genética , RNA Mensageiro/metabolismo , Regulação para CimaRESUMO
Phosphorus accumulating organisms (PAOs) have been found to act as glycogen-accumulating organisms (GAOs) under certain conditions, thus, the deterioration in the performance of enhanced biological phosphorus removal systems is not always attributed to the proliferation of GAOs. In this work, the effects of calcium on the metabolic pathway of PAOs were explored. It was found that when the influent Ca(2+) concentration was elevated, the tendency and extent of extracellular calcium phosphate precipitation increased, and the intracellular inert Ca-bound polyphosphate was synthesized, while the microbial population remained almost unchanged. The changes in the ratios of phosphorus released/acetate uptaken, the glycogen degraded/acetate uptaken and the poly-ß-hydroxyalkanoates synthesized/acetate uptaken during the anaerobic period confirm that, as the influent Ca(2+) concentration was increased, the polyphosphate-accumulating metabolism was partially shifted to the glycogen-accumulating metabolism. At an influent Ca(2+) around 50 mg/L, in addition to the extracellular calcium phosphate precipitation, the intracellular inert Ca-bound polyphosphate synthesis might also be involved in the metabolic change of PAOs. The results of the present work would be beneficial to better understand the biochemical metabolism of PAOs in enhanced biological phosphorus removal systems.
Assuntos
Reatores Biológicos , Cálcio/metabolismo , Fósforo/metabolismo , Glicogênio/metabolismo , Esgotos/microbiologia , Purificação da ÁguaRESUMO
Gastric cancer (GC) is the fourth and fifth most common cancer in men and women, respectively. We identified 2,750 proteins at false discovery rates of 1.3% (protein) and 0.03% (spectrum) by comparing the proteomic profiles of three GC and a normal gastric cell lines. Nine proteins were significantly dysregulated in all three GC cell lines, including filamin C, a muscle-specific filamin and a large actin-cross-linking protein. Downregulation of filamin C in GC cell lines and tissues were verified using quantitative PCR and immunohistochemistry. Data-mining using public microarray datasets shown that filamin C was significantly reduced in many human primary and metastasis cancers. Transient expression or silencing of filamin C affected the proliferation and colony formation of cancer cells. Silencing of endogenous filamin C enhanced cancer cell migration and invasion, whereas ectopic expression of filamin C had opposing effects. Silencing of filamin C increased the expression of matrix metallopeptidase 2 and improved the metastasis of prostate cancer in a zebrafish model. High filamin C associated with better prognosis of prostate cancer, leukemia and breast cancer patients. These findings establish a functional role of filamin C in human cancers and these data will be valuable for further study of its mechanisms.
Assuntos
Filaminas/metabolismo , Neoplasias/metabolismo , Proteoma/metabolismo , Proteômica/métodos , Neoplasias Gástricas/metabolismo , Adulto , Idoso , Idoso de 80 Anos ou mais , Linhagem Celular Tumoral , Movimento Celular/genética , Proliferação de Células/genética , Cromatografia Líquida , Feminino , Filaminas/genética , Regulação Neoplásica da Expressão Gênica , Humanos , Imuno-Histoquímica , Masculino , Espectrometria de Massas , Pessoa de Meia-Idade , Neoplasias/genética , Neoplasias/patologia , Proteoma/genética , Interferência de RNA , Reação em Cadeia da Polimerase Via Transcriptase Reversa , Neoplasias Gástricas/genética , Neoplasias Gástricas/patologiaRESUMO
Cystic hydatid disease is an important zoonosis caused by Echinococcus granulosus infection. The expression profiles of its parasitic life stages and host-Echinococcus interactions remain to be elucidated. Here, we identified 157 adult and 1588 protoscolex proteins (1610 in all), including 1290 novel identifications. Paramyosins and an antigen B (AgB) were the dominant adult proteins. Dog proteins (30) identified in adults indicated diminished local inflammation caused by adult infection. The protoscolex expresses proteins that have been reported to be antigens in other parasites, such as 6-phosphofructokinase and calcineurin B. Pathway analyses suggested that E. granulosus uses both aerobic and anaerobic carbohydrate metabolisms to generate ATP. E. granulosus expresses proteins involved in synthesis and metabolism of lipids or steroids. At least 339 of 390 sheep proteins identified in protoscolex were novel identifications not seen in previous analyses. IgGs and lambda light chains were the most abundant antibody species. Sheep proteins were enriched for detoxification pathways, implying that host detoxification effects play a central role during host-parasite interactions. Our study provides valuable data on E. granulosus expression characteristics, allowing novel insights into the molecular mechanisms involved in host-parasite interactions. BIOLOGICAL SIGNIFICANCE: In this study, the Echinococcus granulosus adult worm proteome was analyzed for the first time. The protein identification of E. granulosus protoscoleces was extended dramatically. We also identified the most abundant host proteins co-purified with Echinococcus. The results provide useful information pertaining to the molecular mechanisms behind host-Echinococcus interaction and Echinococcus biology. This data also increases the potential for identifying vaccine candidates and new therapeutic targets, and may aid in the development of protein probes for selective and sensitive diagnosis of echinococcosis infection. In addition, the data collected here represents a valuable proteomic resource for subsequent genome annotation.
Assuntos
Doenças do Cão/metabolismo , Equinococose/metabolismo , Equinococose/veterinária , Echinococcus granulosus/fisiologia , Interações Hospedeiro-Parasita/fisiologia , Proteínas de Protozoários/metabolismo , Animais , Doenças do Cão/parasitologia , Cães , Equinococose/parasitologia , Larva/metabolismo , Proteômica/métodosRESUMO
The tegument proteins of schistosome have attracted the most attention in studies of host-parasite interplay, while the host proteins acting at the host-parasite interface remained largely elusive. Here, we undertook a high-throughput proteomic approach to characterize the schistosome-adsorbed host proteins. Fifty five distinct host proteins were confidently identified in S. japonicum samples, including cercaria, schistosomula, adults, eggs, and miracidia, together with tegument and eggshell preparations, of which 23 and 38 host proteins were identified in adult worms and eggs, respectively. Among the schistosome-adsorbed host proteins, host neutrophil elastases were found in the granuloma initiated by schistosome egg deposition, implying that the host innate immune molecules could participate in the granuloma formation for fighting against schistosome invasion, except for the adaptive immune system. In addition, some host proteins, such as proteinase inhibitor and superoxide dismutase, might be utilized by schistosome to counteract or attenuate the host attacks. These parasite-adsorbed host proteins will provide new insights into the host immune responses against schistosome infection, the evasive behavior of the adult worms, and the granuloma formation, which could render an in-depth understanding for the host-parasite interplay.
Assuntos
Proteínas de Helminto/metabolismo , Proteômica , Schistosoma japonicum/metabolismo , Animais , Feminino , Proteínas de Helminto/isolamento & purificação , Interações Hospedeiro-Parasita/fisiologia , Humanos , Masculino , Proteômica/métodos , Coelhos , Schistosoma japonicum/isolamento & purificaçãoRESUMO
Hepatocellular carcinoma (HCC) is the third leading cause of cancer mortality worldwide and ranks second in China. The prognosis of HCC remains dismal mainly because of its late diagnosis, especially in patients with coexisting chronic liver diseases. To identify serum biomarkers for HCC, sera from 20 healthy volunteers, 20 hepatitis B virus (HBV) infected patients and 20 HCC patients were selected for screening study and same number of sera into the same three groups were used for validation study. A strategy including sonication, albumin and immunoglobulin G (IgG) depletion and desalting was optimized for screening differentially expressed proteins of low abundance in serum. By 2-DE image analysis and MALDI-TOF-MS/MS identification, eight proteins including heat-shock protein 27 (HSP27), alpha-fetoprotein (AFP), alpha-1 antitrypsin, clusterin, caeruloplasmin, haptoglobin alpha2 chain, tranferrin and transthyretin were found significantly changed among the healthy, HBV and HCC groups. Further validation study by Western blot showed the detection of HSP27 in 90% HCC sera and two HBV sera, but in none of normal sera. Thus, 2-DE based serum proteome analysis can be useful in the screening of serum biomarkers for HCC and HSP27 could aid in the diagnosis of HCC though further validation is needed.