Downregulation of hnRNP C1/C2 by siRNA sensitizes HeLa cells to various stresses

Hossain, Mohammad Nazir; Fuji, Michihiko; Miki, Kensuke; Endoh, Morio; Ayusawa, Dai

doi:10.1007/s11010-006-9308-2

Cited by 34 publications

(30 citation statements)

References 33 publications

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“…Down-regulation of the hnRNP C1/C2 protein amount was reported in acute promyelocytic leukaemia upon treatment with all-transretinoic acid (Harris et al 2004). Decrease in hnRNP C1/ Protein spots concordantly identified in the c-myc-downregulated as well as the control group are marked bold C2 levels itself was correlated to higher sensitivity towards chemical stress (Hossain et al 2007). HnRNP C1/C2 was proven to bind to p53 mRNA and this binding is strongly enhanced in response to cytotoxic drugs, which increase cytosolic hnRNP C1/C2 levels (Christian et al 2008).…”

Section: Discussionmentioning

confidence: 90%

Identification of c-myc-dependent proteins in the medulloblastoma cell line D425Med

Azizi

Ströbel

et al. 2011

Amino Acids

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High c-myc levels are linked to poor prognosis in medulloblastoma (MB), and it was the aim of the current study to search for c-myc-dependent proteins in the MB cell line D425Med. For this purpose D425Med cells and cells with knocked-down c-myc (by siRNA) were analysed by a gel-based differential proteomics study using mass spectrometry. Heterogeneous nuclear ribonucleoproteins C1/C2, heterogeneous nuclear ribonucleoprotein A/B, stathmin, endoplasmic reticulum protein ERp29 precursor and guanidinoacetate N-methyltransferase were c-myc dependently expressed. Signalling, the protein machinery, metabolism and endoplasmic reticulum function may be affected and these results enable studying tumour tissue for these proteins as potential dignity markers or pharmacological targets.

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Section: Discussionmentioning

confidence: 90%

Identification of c-myc-dependent proteins in the medulloblastoma cell line D425Med

Azizi

Ströbel

et al. 2011

Amino Acids

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“…The hnRNP C proteins, which belong to a large family of RNA motif-binding RNPs, are among the most abundant nuclear proteins involved in mRNA biogenesis, DNA repair [31,32], the cell cycle, apoptosis [33,34], and the maintenance of cellular homeostasis [35]. In normal proximal internal carotid arteries, hnRNP C proteins are expressed predominantly in the endothelium, with significantly lower expression in medial smooth muscle.…”

Section: Discussionmentioning

confidence: 99%

The Most Negatively Charged Low-Density Lipoprotein L5 Induces Stress Pathways in Vascular Endothelial Cells

Chen¹,

Hsu²,

Lee

et al. 2012

J Vasc Res

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Background/Aims: L5, the most negatively charged species of low-density lipoprotein (LDL), has been implicated in atherogenesis by inducing apoptosis of endothelial cells (ECs) and inhibiting the differentiation of endothelial progenitor cells. In this study, we compared the effects of LDL charge on cellular stress pathways leading to atherogenesis. Methods: We isolated L5 and L1 (the least negatively charged LDL) from the plasma of patients with familial hypercholesterolemia and used JC-1 staining to examine the effects of L5 and L1 on the mitochondrial membrane potential (DCm) in human umbilical vein ECs (HUVECs). Additionally, we characterized the gene expression profiles of 7 proteins involved in various types of cellular stress. Results: The DCm was severely compromised in HUVECs treated with L5. Furthermore, compared with L1, L5 induced a decrease in mRNA and protein expression of the endoplasmic reticulum (ER) chaperone proteins ORP150, Grp94, and Grp58, mitochondrial proteins Prdx3 and ATP synthase, and an increase in the expression of the pro-inflammatory protein hnRNP C1/C2. Conclusions: Our work suggests that L5, but not L1, may promote the destruction of ECs that occurs during atherogenesis by causing mitochondrial dysfunction and modulating the expression of key proteins to promote inflammation, ER dysfunction, oxidative stress, and apoptosis.

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“…It is a compo- nent of the spliceosome complex (38), and a recent study using a hnRNP C knockdown approach identified BCL2L12 and PCBP4 as genes whose splicing is regulated by hnRNP C (39). Additional functions, such as regulating telomerase activity (40), XIAP translation through the IRES promoter (41), and response to hydrogen peroxide stress (42,43) have been attributed to hnRNP C. The interaction of PTEN with hnRNP C and the complex assembly may be important in regulating these known hnRNP C functions.…”

Section: Discussionmentioning

confidence: 99%

Analysis of PTEN Complex Assembly and Identification of Heterogeneous Nuclear Ribonucleoprotein C as a Component of the PTEN-associated Complex

Mosessian

Avliyakulov

Mulholland

et al. 2009

Journal of Biological Chemistry

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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 sizeexclusion 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.Phosphatase and tensin homolog deleted on chromosome 10 (PTEN) 4 was cloned in 1997 (1-3) and has been well characterized for its tumor-suppressive role by dephosphorylating phosphatidylinositol 3,4,5-trisphosphate to phosphatidylinositol 4,5-bisphosphate and antagonizing the phosphoinositide 3-kinase pathway (4 -7). PTEN also regulates cell migration, cell cycle progression, DNA damage response, and chromosome stability independently of its lipid phosphatase activity through its potential protein phosphatase activity and/or protein-protein interaction (8 -11) (for recent reviews, see [12][13][14].PTEN is composed of an N-terminal catalytic domain and a C-terminal regulatory domain. The catalytic domain contains a conserved signature motif (HCXXGXXR) found in dual-specific protein phosphatases, and mutations within this catalytic domain, including the C124S mutation, are known to abrogate PTEN catalytic activity (4). The C terminus of PTEN contains a PDZ (PDS-95/Disc-large/Zo-1) binding domain, which interacts with PDZ-containing proteins such as MAGI-1b, MAGI-2, MAGI-3, hDLG, hMAST and NHERF (15)(16)(17)(18)(19). In addition to the PDZ binding domain, several key serine and threonine phosphorylation sites (Ser 380 , Thr 382 , Thr 383 , and Ser 385 ) at the PTEN C terminus are reported to play an important role in regulating its stability, localization, and activity (20 -26).Recent studies suggest that PTEN may function within higher molecular mass complexes. Through size-exclusion chromatography, Vazquez et al. (27) demonstrated that...

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Downregulation of hnRNP C1/C2 by siRNA sensitizes HeLa cells to various stresses

Cited by 34 publications

References 33 publications

Identification of c-myc-dependent proteins in the medulloblastoma cell line D425Med

Identification of c-myc-dependent proteins in the medulloblastoma cell line D425Med

The Most Negatively Charged Low-Density Lipoprotein L5 Induces Stress Pathways in Vascular Endothelial Cells

Analysis of PTEN Complex Assembly and Identification of Heterogeneous Nuclear Ribonucleoprotein C as a Component of the PTEN-associated Complex

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