Dataset Information

Analysis of PTEN complex assembly and identification of heterogeneous nuclear ribonucleoprotein C as a component of the PTEN-associated complex.

ABSTRACT: PTEN (phosphatase and tensin homolog deleted on chromosome 10) is well characterized for its role in antagonizing the phosphoinositide 3-kinase pathway. Previous studies using size-exclusion chromatography demonstrated PTEN recruitment into high molecular mass complexes and hypothesized that PTEN phosphorylation status and PDZ binding domain may be required for such complex formation. In this study, we set out to test the structural requirements for PTEN complex assembly and identify the component(s) of the PTEN complex(es). Our results demonstrated that the PTEN catalytic function and PDZ binding domain are not absolutely required for its complex formation. On the other hand, PTEN phosphorylation status has a significant impact on its complex assembly. Our results further demonstrate enrichment of the PTEN complex in nuclear lysates, suggesting a mechanism through which PTEN phosphorylation may regulate its complex assembly. These results prompted further characterization of other protein components within the PTEN complex(es). Using size-exclusion chromatography and two-dimensional difference gel electrophoresis followed by mass spectrometry analysis, we identified heterogeneous nuclear ribonucleoprotein C (hnRNP C) as a novel protein recruited to higher molecular mass fractions in the presence of PTEN. Further analysis indicates that endogenous hnRNP C and PTEN interact and co-localize within the nucleus, suggesting a potential role for PTEN, alongside hnRNP C, in RNA regulation.

SUBMITTER: Mosessian S

PROVIDER: S-EPMC2781571 | biostudies-literature | 2009 Oct

REPOSITORIES: biostudies-literature

ACCESS DATA

Publications

Analysis of PTEN complex assembly and identification of heterogeneous nuclear ribonucleoprotein C as a component of the PTEN-associated complex.

Mosessian Sherly S Avliyakulov Nuraly K NK Mulholland David J DJ Boontheung Pinmanee P Loo Joseph A JA Wu Hong H

The Journal of biological chemistry 20090909 44

PTEN (phosphatase and tensin homolog deleted on chromosome 10) is well characterized for its role in antagonizing the phosphoinositide 3-kinase pathway. Previous studies using size-exclusion chromatography demonstrated PTEN recruitment into high molecular mass complexes and hypothesized that PTEN phosphorylation status and PDZ binding domain may be required for such complex formation. In this study, we set out to test the structural requirements for PTEN complex assembly and identify the compone ...[more]

PMID: 19740742

Similar Datasets

Project description:Active pre-mRNA splicing occurs co-transcriptionally, and takes place throughout the nucleoplasm of eukaryotic cells. Splicing decisions are controlled by networks of nuclear RNA-binding proteins and their target sequences, sometimes in response to signalling pathways. Sam68 (Src-associated in mitosis 68 kDa) is the prototypic member of the STAR (Signal Transduction and Activation of RNA) family of RNA-binding proteins, which regulate splicing in response to signalling cascades. Nuclear Sam68 protein is concentrated within subnuclear organelles called SLM/Sam68 Nuclear Bodies (SNBs), which also contain some other splicing regulators, signalling components and nucleic acids.We used proteomics to search for the major interacting protein partners of nuclear Sam68. In addition to Sam68 itself and known Sam68-associated proteins (heterogeneous nuclear ribonucleoproteins hnRNP A1, A2/B1 and G), we identified hnRNP L as a novel Sam68-interacting protein partner. hnRNP L protein was predominantly present within small nuclear protein complexes approximating to the expected size of monomers and dimers, and was quantitatively associated with nucleic acids. hnRNP L spatially co-localised with Sam68 as a novel component of SNBs and was also observed within the general nucleoplasm. Localisation within SNBs was highly specific to hnRNP L and was not shared by the closely-related hnRNP LL protein, nor any of the other Sam68-interacting proteins we identified by proteomics. The interaction between Sam68 and hnRNP L proteins was observed in a cell line which exhibits low frequency of SNBs suggesting that this association also takes place outside SNBs. Although ectopic expression of hnRNP L and Sam68 proteins independently affected splicing of CD44 variable exon v5 and TJP1 exon 20 minigenes, these proteins did not, however, co-operate with each other in splicing regulation of these target exons.Here we identify hnRNP L as a novel SNB component. We show that, compared with other identified Sam68-associated hnRNP proteins and hnRNP LL, this co-localisation within SNBs is specific to hnRNP L. Our data suggest that the novel Sam68-hnRNP L protein interaction may have a distinct role within SNBs.

Project description:Background Hepatocellular carcinoma (HCC) is the most common type of liver cancer with a high mortality rate. However, spliceosomal genes are still lacking in the diagnosis and prognosis of HCC. Methods Identification of differentially expressed genes (DEGs) was performed using the limma package in R software. Modules highly related to HCC were obtained by weighted gene co-expression network analysis (WGCNA), and the module genes were analyzed using the Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway. The biomarker for diagnosing HCC was determined by receiver operating characteristic (ROC) curve analysis, and the effect of the biomarker in the diagnosis of HCC was evaluated by performing five-fold cross-validation with logistic regression. HCC specimens from preoperatively treated patients were tested for biomarker by real-time quantitative polymerase chain reaction (RT-qPCR). Kaplan-Meier analysis was used to assess the relationship between biomarker and patient survival. The role of biomarker was evaluated using ESTIMATE analysis in the tumor microenvironment. Results In this study, 389 DEGs were screened out from three Gene Expression Omnibus (GEO) datasets. We also found that the turquoise module of 123 genes from The Cancer Genome Atlas (TCGA) data was the key module with the highest correlation with HCC traits. Then, 123 genes were analyzed using the KEGG enrichment pathway, and eight genes were found to be most significantly related to the spliceosome pathway. We selected 8 genes and 389 DEGs shared genes, and finally got the only gene, heterogeneous nuclear ribonucleoprotein (hnRNPU). The high expression of hnRNPU was associated with poor prognosis of HCC, and hnRNPU was a biomarker for diagnosing HCC. In the tissues of patients with excellent HCC treatment hnRNPU messenger RNA (mRNA) was lower than in the tissues of patients with poor HCC treatment. High expression of hnRNPU was significantly increased in HCC patients with low stromal (P<0.05), low immune (P<0.05), and low estimation scores (P<0.05), and with high tumor purity (P<0.05) and high malignant progression (P<0.05) of the HCC. Conclusions The hnRNPU gene identified in this study may become a new biomarker for the diagnosis and prognosis of HCC.

Dataset Information

Analysis of PTEN complex assembly and identification of heterogeneous nuclear ribonucleoprotein C as a component of the PTEN-associated complex.

Publications

Analysis of PTEN complex assembly and identification of heterogeneous nuclear ribonucleoprotein C as a component of the PTEN-associated complex.

Similar Datasets

OmicsDI is part of the ELIXIR infrastructure

Tweets