Search PubMed⌕ Search

SEARCH · Search PubMed

Results for “Nuclear Matrix”

Search indexed PubMed citations on genomics, clinical trials, systematic reviews and public health. Explore titles, authors and supplied subject terms, then open the PubMed record.

Quote a phrase for an exact phrase match. Source license links do not imply unrestricted reuse.

At least 811 records · Page 45Linked to original sources
PubMed1983

Nuclear matrix: a cell-cycle-dependent site of increased intranuclear protein phosphorylation.

Evidence is presented that the nuclear matrix is a cell-cycle-dependent site of increased intranuclear protein phosphorylation. The incorporation of radioactive phosphate (32P) is highest during the premitotic (G2) phase and 40-50% less in the postmitotic phase (G1). This is observed for both total matrix protein and for several individual polypeptides ranging in molecular mass from greater than 200 kDa to 19 kDa. The phenomenon can be demonstrated when the matrix is isolated from orthophosphate-labeled intact cells, as well as when the matrix is isolated and then incubated in vitro in a protein kinase reaction mixture. The ability of the isolated matrix to mimic the events in vivo indicates the presence of endogenous protein phosphokinase activity and physiological substrates in this isolated nuclear fraction. Further evidence for such mimicry was obtained when amino acid phosphorylation sites were determined. Phosphoserine is the most abundant phosphoamino acid in the matrix labelled both in vitro and in vivo, although phosphothreonine and phosphotyrosine are also present. On the basis of several pieces of data, the endogenous matrix activity appears to be due to multiple protein phosphokinases. Since the maximum phosphorylation coincides with premitosis, the phosphoproteins may play a role in mitotic events. These observations extend and expand the application of this fraction to the study of nuclear structure/function relationships, particularly at the time of mitosis.

Binding Sites↗
PubMed2006

Emp is a component of the nuclear matrix of mammalian cells and undergoes dynamic rearrangements during cell division.

Emp, originally detected in erythroblastic islands, is expressed in numerous cell types and tissues suggesting a functionality not limited to hematopoiesis. To study the function of Emp in non-hematopoietic cells, an epitope-tagged recombinant human Emp was expressed in HEK cells. Preliminary studies revealed that Emp partitioned into both the nuclear and Triton X-100-insoluble cytoskeletal fractions in approximately a 4:1 ratio. In this study, we report investigations of Emp in the nucleus. Sequential extractions of interphase nuclei showed that recombinant Emp was present predominantly in the nuclear matrix. Immunofluorescence microscopy showed that Emp was present in typical nuclear speckles enriched with the spliceosome assembly factor SC35 and partially co-localized with actin staining. Coimmunoprecipitation and GST-pull-down assays confirmed the apparent close association of Emp with nuclear actin. During mitosis, Emp was detected at the mitotic spindle/spindle poles, as well as in the contractile ring during cytokinesis. These results suggest that Emp undergoes dynamic rearrangements within the nuclear architecture that are correlated with cell division.

Actins↗
PubMed2003

Role of cytokeratins, nuclear matrix proteins, Lewis antigen and epidermal growth factor receptor in human bladder tumors.

The content of urinary bladder cancer antigen (UBC), tissue polypeptide specific antigen (TPS), nuclear matrix protein 22 (NMP22), and the expression of LewisY carbohydrate antigens and of epidermal growth factor receptor (EGF-R) in bladder tumor tissues were determined. These included 14 well, 6 moderately and 11 poorly differentiated bladder cancers. Cytosol UBC and TPS were higher in the well and in the moderately differentiated bladder tumors than in the poorly differentiated bladder cancers; whereas cytosol NMP22 was higher in the poorly differentiated bladder cancers than in the well and in the moderately differentiated bladder tumors. The Lewis related carbohydrate antigens, evaluated by the reactivity of the tissues to monoclonal antibody B3, were highly expressed in poorly differentiated tumors. The EGF-R was strongly expressed in a large number of poorly differentiated bladder tumors. These data suggest that the determination of cytosol NMP22 and the immunoblotting with B3 and EGF-R antibodies might be useful to obtain more information on the differentiation of bladder tumors.

Aged↗
PubMed1994

Localization of NuMA protein isoforms in the nuclear matrix of mammalian cells.

Using a monoclonal antibody 2D3 generated against a kinetochore-enriched human chromosome preparation, we identified a high molecular mass protein with nuclear staining in interphase and polar staining of the pericentriolar region in the mitotic spindle. Initially termed centrophilin, this protein associates with the minus-ends of spindle microtubules (MT) and appears to be important in spindle organization [Tousson et al., 1991: J. Cell Biol. 112:427-440]. Comparison of a partial cDNA sequence obtained for centrophilin with the full length cDNA sequence of nuclear mitotic apparatus protein (NuMA) [Compton et al., 1992: J. Cell Biol. 116:1395-1408; Yang et al., 1992: J. Cell Biol. 116:1303-1317] has indicated that NuMA and centrophilin are the same protein. Using a polyclonal NuMA antibody, we have provided further evidence that NuMA exists as isoforms as shown by peptide mapping and immunoblots. Sequential fractionation experiments along with immunofluorescence, immunoblotting, and EM immunogold labeling have demonstrated that NuMA isoforms are novel components of nuclear core filaments. Thus, NuMA, a long coiled-coil protein, appears to have dual functions in interphase and mitosis during the cell cycle. In interphase, NuMA likely plays a structural role in the nucleoskeleton that may be important in nuclear organization and functions, whereas in mitosis, NuMA appears to be associated with spindle MT organization and chromosome positioning.

Antigens, Nuclear↗
PubMedDate not supplied

Nuclear matrix bound terminal deoxynucleotidyl transferase in rat thymus nuclei. II. Effect of ATP on free and matrix bound TdT.

Endogenous nuclease digestion of thymus nuclei from 3-4 week old rats followed by a step wise extraction with low salt, 0.5 M salt and 1 M salt removed approximately 70-85% of total nuclear terminal deoxynucleotidyl transferase (TdT) whereas approximately 15-30% of the enzyme remained tightly bound to the residual nuclear matrix. The cytoplasmic TdT as well as the bulk of nuclear TdT extracted in low salt and 0.5 M salt was found to be strongly inhibited at low concentration of ATP whereas matrix bound TdT and a significant portion of the enzyme in 1 M salt extract was completely insensitive to this nucleotide. The ATP resistant enzyme in the 1 M salt extract was unstable and slowly converted to ATP sensitive form upon prolonged preincubation on ice whereas under similar conditions it remained unaffected in the matrix bound form. These observations lead us to suggest that ATP resistant matrix bound TdT being capable of discriminating unnatural rNTPs against the natural dNTP substrates, may be the functionally organized form of the enzyme and that free TdT having lost the capability to distinguish between dNTP and rNTP may be the nonfunctional form of the enzyme in the thymus gland.

Adenosine Triphosphate↗
PubMed2005

An office-based immunodiagnostic assay for detecting urinary nuclear matrix protein 52 in patients with bladder cancer.

OBJECTIVE: To report the rapid (5 min) and simple detection of a nuclear matrix protein (NMP) in the urine of patients with bladder cancer, using a newly developed office-based dot-enzyme-linked immunosorbent assay (ELISA). PATIENTS AND METHODS: Western blot and specific immunoglobulin-G antibody were used to identify the urinary NMP marker. Urine samples from 149 patients with bladder cancer and 72 controls were evaluated using the developed dot-ELISA. The initial responses of 43 patients treated by irradiation were followed using the assay. RESULTS: The NMP marker was identified in the urine of patients with bladder cancer at 52 kDa (NMP-52) by Western blot. The dot-ELISA detected the urinary NMP-52 marker in 92% of patients with squamous cell carcinoma, 98% with transitional cell carcinoma, and all six of those with adenocarcinoma of the bladder, with a specificity of 94%. The positive and negative predictive values (97% and 94%, respectively) and efficiency (96%) of the dot-ELISA were high. In addition, the NMP-52 tumour marker was not detected in the urine of patients who showed a response after radiotherapy. CONCLUSION: Detecting the urinary NMP-52 marker using dot-ELISA would be helpful in the rapid diagnosis and follow-up of patients with bladder cancer.

Adult↗
PubMed1996

Changes in the nuclear matrix of chicken erythrocytes that accompany maturation.

The protein composition and structure of nuclear matrices isolated from adult chicken immature and mature erythrocytes were analysed. Visualization of nuclear matrices by electron microscopy showed that immature-erythrocyte nuclear matrices had internal structures, while most mature-erythrocyte nuclear matrices did not. Both mature- and immature-erythrocyte nuclear matrices were surrounded by a fibrous network of intermediate filaments. Two-dimensional gel electrophoretic analysis of proteins obtained from fractionated nuclear matrices led to the assignment of the proteins as components of the nuclear porelamina, internal matrix, or cytoskeleton. Common and different proteins belonging to one of the three groups were identified in nuclear matrices of immature and mature erythrocytes. Investigation of the partitioning of histone deacetylase activity, an enzyme associated with the internal matrix, among the erythroid nuclear matrix fractions provided evidence that mature- and immature-erythrocyte nuclear matrices have internal structures. However, the activity of histone deacetylase and level of internal matrix proteins from mature-erythrocyte nuclear matrices were less than those from immature-erythrocyte matrices. The low levels of nuclear RNA and internal matrix proteins may account for lack of visual evidence for an internal matrix in mature erythrocytes.

Animals↗
PubMed1989

The use of a monoclonal antibody against a proliferating cell nuclear matrix antigen in the study of solid human tumors.

A monoclonal antibody (MAb) identifies the nuclear antigen p125/6.5 associated with the nuclear matrix and present in proliferating human cells. By direct and indirect immunofluorescence, the presence and distribution of the antigen p125/6.5 in cryostat sections from primary and metastatic solid human tumors has been investigated. The antigen is present in nuclei of malignant and benign tumor cells, but is not detected in adjacent normal tissues. The antigen displays a speckled nucleoplasmic distribution, while nucleoli are negative. The intensity of the immunofluorescence reaction is markedly higher in the nuclei of some individual or grouped tumor cells.

Antibodies, Monoclonal↗
PubMed2003

Nuclear matrix proteins changes in cancerous prostate tissues and their prognostic value in clinically localized prostate cancer.

BACKGROUND: After the discovery that nuclear matrix (NM) directs the spatial organization of DNA transcription and replication, there has been an increasing interest in studying NM changes associated with malignant transformation and their potential usefulness in the clinical setting. METHODS: High-resolution two-dimensional gel electrophoresis was used to analyze the NM proteins (NMP) of specimens of prostate cancer tissue obtained from the prostates of 75 patients undergoing retropubic prostatectomy. RESULTS: Nine NMP with different molecular weights and isoelectric points have been identified. They were expressed differently by prostate cancer tissues. An increasing trend toward the expression of such proteins like NMP 6-8 was evident with increasing tumor stage and dedifferentiation. NMP 6-8 were also significantly correlated with the risk of biochemical progression. However, Gleason score was the only significant discriminant in this regard in multiparametric models. CONCLUSIONS: This study confirms that prostate cancer progression is related to profound changes in NMP expression patterns. However, due to the complexity of the methods required to define these latter, the clinical relevance of NMP appears to be still limited.

Aged↗
PubMed2004

Risk stratification for bladder tumor recurrence, stage and grade by urinary nuclear matrix protein 22 and cytology.

PURPOSE: To test the hypothesis that voided urinary levels of nuclear matrix protein 22 (NMP22) would add to the predictive ability of urine cytology in the diagnosis, staging and grading of bladder transitional cell carcinoma (TCC), and to evaluate the diagnostic performance of different NMP22 cut-points. MATERIALS: NMP22 level and barbotage cytology were evaluated in voided urine specimens collected before cystoscopy from 302 subjects with a history of TCC, 32 subjects with benign urologic pathologies, and 10 healthy volunteers. RESULTS: 180 patients (52%) had bladder TCC. Higher levels of NMP22 and positive cytology were independently associated with an increased risk of TCC, invasive stage, and high grade. The NMP22 value with equal sensitivity and specificity for prediction of bladder cancer was 6.5U/ml; for prediction of grade 3 TCC it was 13.5U/ml; and for prediction of invasive tumor stage it was 17.4U/ml. The NMP22 cut-point of 6.5U/ml outperformed the 10U/ml cut-point in all pathologic stages and grades. The diagnostic sensitivity of the cytology and NMP22 combined was superior across all pathologic stages and grades to that of either marker alone. NMP22 and cytology stratified patients into groups with significantly different risk for TCC presence, invasive stage, and high grade. CONCLUSIONS: 6.5U/ml is a robust NMP22 cut-point for bladder cancer surveillance. The diagnostic sensitivities of the combined NMP22 and cytology for TCC presence, stage, and grade were significantly higher than those of single marker alone. The combination of urine cytology and NMP22 could be used to tailor the frequency of cystoscopic follow up.

Adult↗
PubMed2005

Entamoeba histolytica DNA methyltransferase (Ehmeth) is a nuclear matrix protein that binds EhMRS2, a DNA that includes a scaffold/matrix attachment region (S/MAR).

The protozoan parasite Entamoeba histolytica express a cytosine-5 DNA methyltransferase (Ehmeth) that belongs to the DNMT2 protein family. The biological function of members of this DNMT2 family is unknown. In the present study, we have demonstrated that Ehmeth is a nuclear matrix protein. Indeed, we showed by south-western analysis and yeast one-hybrid system that Ehmeth binds to EhMRS2, a DNA element which contains the eukaryotic consensus scaffold/matrix attachment regions (S/MAR) bipartite recognition sequences. S/MARs have been implicated in a variety of important functions, such as genome organization and gene expression. The methylation status of cytosine located within EhMRS2 was analyzed by bisulfite genomic sequencing. We observed the presence of methylated cytosine within the 3'-end of EhMRS2. These data provide the first evidence that a member of the DNMT2 family interacts with a S/MAR containing DNA element.

Animals↗
PubMed1991

Molecular cloning of matrin F/G: A DNA binding protein of the nuclear matrix that contains putative zinc finger motifs.

We have isolated a 2.7-kilobase rat liver cDNA clone that contains the entire 544-amino acid coding sequence for matrin F/G. This protein has previously been localized to the internal, fibrogranular areas of the nuclear matrix and shown to bind to DNA on nitrocellulose blots. The predicted amino acid sequence from the coding region of this cDNA shows that this protein contains approximately 50% hydrophobic amino acids with secondary structure predictions suggesting a large percentage of beta-sheet regions. No significant homologies were found with any other known proteins, including the nuclear lamins. The predicted amino acid sequence was also searched for DNA binding motifs. Two putative zinc finger motifs were found. In addition, a 7-mer palindromic sequence (Ser-Ser-Thr-Asn-Thr-Ser-Ser) was discovered within one of these zinc finger DNA binding regions. A possible regulatory role for this element is discussed.

Amino Acid Sequence↗
PubMed2004

Nuclear matrix protein expressions in hepatocytes of normal and cirrhotic rat livers under normal and regenerating conditions.

We explored the feasibility of studying nuclear matrix protein (NMP) expressions of the hepatocytes in normal and cirrhotic rat livers with liver regeneration after partial hepatectomy. Sixteen Wistar healthy rats were studied with experimental liver regeneration and/or liver cirrhosis. Two-dimensional (2-D) gel electrophoresis was used to generate these NMP compositions from these rat liver samples. Several antibodies against cytokeratin, vimentin, actin, B23, HNF4alpha, and heat shock protein 70 were used for identification by Western blot. Totally, 41 strongly stained protein spots were characterized on the 2-D gels. Thirty-four protein spots were detected in all of these rat livers, of which, cytokeratin, vimentin, actin, HNF4alpha, and heat shock protein 70 were identified. B23 was detected in the regenerated livers. Three protein spots (s33, s34, and s35) were detectable only in NMP preparation extracted from the regenerating rat livers after hepatectomy. Another three protein spots (s36, s37, and s38) were detectable only in NMP preparation extracted from thioacetamide-induced cirrhotic rat livers. Under these conditions including experimental liver regeneration and/or liver cirrhosis, Over thirty higher abundance NMPs of hepatocytes were consistently expressed and considered as common and basic NMPs. Some of the NMPs are specific for liver regeneration and may play a critical role in cell proliferation and cell cycle, and some are specific for liver cirrhosis.

Animals↗
PubMed2000

Poly-A-rich domains in adrenal cell nuclear matrix after acute and chronic ACTH stimulation: an in situ hybridization study.

The regulatory effects of adrenocorticotropin (ACTH) at the adrenal cell nucleus are not yet completely clarified. Recent studies showed that eukaryotic cell nucleus is composed of specific subcompartments organized by the nucleoskeleton-nuclear matrix. In this paper, the RNA polymerase II transcriptional domains were detected in the adrenal nucleus after acute and chronic ACTH stimulation by using in situ hybridization. Polydeoxythymidine (poly-T) probe, complementary to the polyadenylated (poly-A) chain of all the mRNAs and its precursors, was used. Hybridization was performed in intact adrenal cells and in nuclear matrices isolated from previously dispersed cells. The transcriptional domains, enriched in poly-A RNA, were evident in intact adrenal cells, the staining intensity being higher both in the acutely and in the chronically stimulated animals. In the nuclear matrices poly-A-rich areas were still visible, and were more intensely stained after ACTH stimulation.

Adrenal Glands↗
PubMed1999

Human nuclear matrix contains a protein complex which can specifically recognize alpha-satellite DNA in vitro.

A nuclear matrix protein complex has been found which specifically binds to alpha-satellite DNA as revealed by gel shift assay. The complex contains three proteins--two DNA-binding proteins with molecular masses of 70 and 80 kD and a 58-kD protein which does not bind DNA but enhances the specificity of binding of the others to alpha-satellite DNA. The complex does not contain CENP-A, CENP-B, CENP-C, CENP-G, or lamins A/C and B.

Antigens, Nuclear↗
PubMed1989

DNA-protein complexes of the nuclear matrix: visualization and partial characterization of the protein component.

Complexes composed of DNA attached to the nuclear matrix and of proteins most tightly bound to DNA are visualized as globular particles 25-35 nm in diameter. Their morphology depends greatly on the isolation conditions: a Cs salts/urea combination permits the isolation while CsCl/sarcosyl destroys the particles. The preparation is shown to have the same protein content regardless of the treatment employed. The proteins of the complex are resistant to SDS and pronase treatment and to phenol/chloroform extraction while being associated with DNA.

Animals↗
PubMed2000

[Evaluation of restenosis by serum levels of soluble Fas, Fas ligand and nuclear matrix protein before and after coronary intervention].

Serum levels of soluble Fas, soluble Fas ligand, and nuclear matrix protein (NMP) were measured in 38 patients with ischemic heart disease before and after coronary angiography or coronary intervention. Serum levels of soluble Fas, soluble Fas ligand and NMP were determined by enzyme-linked immunosorbent assay. Patients one week after undergoing stent implantation had much higher levels of soluble Fas ligand and significantly lower levels of soluble Fas than patients without coronary intervention. Serum levels of soluble Fas ligand and NMP in patients with coronary restenosis were significantly higher than those in patients without restenosis. Serum levels of soluble Fas and soluble Fas ligand in patients one week after undergoing stent implantation who had coronary restenosis were markedly lower and higher than in patients without restenosis, respectively. Serum levels of soluble Fas ligand were positively correlated with NMP in those patients. These results indicate that coronary restenosis might be affected by the Fas/Fas ligand system. We conclude that measurement of soluble Fas, soluble Fas ligand and NMP is useful for determination of coronary restenosis in patients with ischemic heart disease.

Angioplasty, Balloon, Coronary↗