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Objective To investigate the mechanism of 3-phosphoinositide-dependent protein kinase 1(PDK1)poly-ubiquitination.Methods Co-immunoprecipitation(Co-IP)and Western blot(WB)were used to analyze poly-ubiquitination of PDK1.It was confirmed that ubiquitin ligase smad ubiquitylation regulatory factor 1(Smurf1)inprove PDK1 poly-ubiquitination within MEF cells,site-directed mutagenesis and WB before PDK1 poly-ubiquitination sites were determined.Results We found that PDK1 could undergoes poly-ubiquitination,ubiquitin ligase Smurf1 was found to be a direct E3 ligase for PDK1 poly-ubiquitination and might rely on the ubiquitin ligase Smurf 1 K699 site activity.K304 was PDK1 poly-ubiquitination modification site point.Conclusion The ubiquitin ligase Smurf1 can promate poly-ubiquitination of PDK1.
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<p><b>BACKGROUND</b>To compare the clinicopathological features and prognosis between younger and aged patients with hepatocellular carcinoma (HCC).</p><p><b>METHODS</b>We analyzed the outcome of 451 HCC patients underwent liver resection, transcatheter arterial chemoembolization and radiofrequency ablation, respectively. Then risk factors for aged and younger patients' survival were evaluated by multivariate analysis, respectively.</p><p><b>RESULTS</b>The patients who were older than 55 years old were defined as the older group. The overall survival for aged patients was significantly worse than those younger patients. The younger patients had similar liver functional reserve but more aggressive tumor factors than aged patients. Cox regression analysis showed that the elevated levels of aspartate aminotransferase (AST) (Wald χ2 = 3.963, P = 0.047, hazard ratio [HR] =1.453, 95% confidence interval [CI]: 1.006-2.098), lower albumin (Wald χ2 = 12.213, P < 0.001, HR = 1.982, 95% CI: 1.351-2.910), tumor size (Wald χ2 = 8.179, P = 0.004, HR = 1.841, 95% CI: 1.212-2.797), and higher alpha-fetoprotein level (Wald χ2 = 4.044, P = 0.044, HR = 1.465, 95% CI: 1.010-2.126) were independent prognostic factors for aged patients, while only elevated levels of AST (Wald χ2 = 14.491, P < 0.001, HR = 2.285, 95% CI: 1.493-3.496) and tumor size (Wald χ2 = 21.662, P < 0.001, HR = 2.928, 95% CI: 1.863-4.604) were independent prognostic factors for younger patients.</p><p><b>CONCLUSIONS</b>Age is a risk factor to determine the prognosis of patients with HCC. Aged patients who have good liver functional reserve are still encouraged to receive curative therapy.</p>
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Adult , Aged , Aged, 80 and over , Female , Humans , Male , Middle Aged , Young Adult , Age Factors , Carcinoma, Hepatocellular , Mortality , Liver Neoplasms , Mortality , Retrospective Studies , Survival AnalysisABSTRACT
Objective To study the expression of the fused proteasome activator REGγ(11S regulator complex gamma subunit) using gene recombination technology and to further study the interaction between REGγ and casein kinase-2 interacting protein-1(CKIP-1)in vitro.Methods Firstly, the full length cDNA fragment of REGγ was amplified through PCR using the plasmid pCMV-Myc-REGγ as template and subcloned into the prokaryotic expression vector pGEX-4T-2 before being transformed into E.coli BL21 cells. The protein expression was induced by isopropyl-β-D-thiogalactoside(IPTG) .Secondly, the protein expression was monitored by SDS-PAGE and Western blotting after ultrasonication. Finally, the GST Pull-down assay was performed to investigate the interaction between REGγ and CKIP-1 in vitro.Results The prokaryotic expression construct pGEX-4T-2-REGγ was generated successfully and confirmed by DNA sequencing. Expression analysis showed that the GST-REGγ protein was easily expressed and isolated mainly in the lysate supernatant after sonication and centrifugation. The GST Pull-down assay revealed the strong mutual interaction between REGγ and CKIP-1 in vitro.Conclusion The proteasome activator REGγ could interact with the negative regulator of osteoblastogenesis CKIP-1 in vitro and the current study has shed light on further investigations of their physiological relevance.
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Scansite is a short linear motif-based scanning approach established in the latest two years. It's accessible over the World Wide Web and can be used to identify sequence motifs likely to be phosphorylated by specific protein kinases or likely to bind to specific protein domains such as 14-3-3, SH2 and SH3 domains. The usage and function of the potent approach were reviewed and compared with previously established tools for phosphorylation prediction. The facing problems and application outlook of Scansite in prediction of cell signaling networks within proteomes were also presented.