scholarly journals The 72/74-kDa polypeptides of the 70–110S large heterogeneous nuclear ribonucleoprotein complex (LH-nRNP) represent a discrete subset of the hnRNP M protein family

2000 ◽  
Vol 350 (2) ◽  
pp. 495-503 ◽  
Author(s):  
Panayiota KAFASLA ◽  
Meropi PATRINOU-GEORGOULA ◽  
Apostolia GUIALIS
Keyword(s):  
Matrix Protein ◽  
Polyclonal Antibodies ◽  
Protein Family ◽  
M Protein ◽  
Major Protein ◽  
Discrete Subset ◽  
Two Dimensional Gel Electrophoresis ◽  
Nuclear Extracts ◽  
Protein Components ◽  
Nuclear Ribonucleoprotein

Pre-mRNA processing in eukaryotes is thought to take place on a multitude of nuclear ribonucleoprotein (RNP) complexes, the most abundant of them being the heterogeneous nuclear (hn) RNP complexes. The identification in mammalian nuclear extracts of a novel, less-abundant 70–110S heterogeneous RNP, named large heterogeneous nuclear RNP (LH-nRNP), has previously been reported by Aidinis, Sekeris and Guialis (1995) Nucleic Acids Res. 23, 2742–2753. The structural composition of the LH-nRNP complex has been determined following the production of polyclonal antibodies against the major protein constituents of the complex, the pair of the 72/74-kDa polypeptides. In the present study evidence is shown to prove that the 72/74-kDa proteins are members of the hnRNP M protein family, hereafter referred to as 72/74(M) polypeptides. The extensive application of two-dimensional gel electrophoresis, combined with specific immunoprecipitation and immunoblotting assays, has allowed the assignment of the 72/74(M) proteins to a subset of the hnRNP M family, characteristic of the presence of the LH-nRNP complex and distinct from the hnRNP-associated M1–M4 components. Moreover, the immunoselection of the LH-nRNP complex from [32P]orthophosphate-labelled HeLa cells, with the parallel application of UV irradiation, has permitted the identification of the 72/74(M) polypeptides as the sole protein constituents of the complex in direct contact with the RNA. It is proposed that LH-nRNP constitutes a discrete subset of hnRNP complexes, having a possible role in establishing specific interactions between hnRNP and nuclear-matrix protein components.

scholarly journals Recognition of subsets of the mammalian A/B-type core heterogeneous nuclear ribonucleoprotein polypeptides by novel autoantibodies

1996 ◽  
Vol 320 (3) ◽  
pp. 761-767 ◽  
Author(s):  
Amalia DANGLI ◽  
Angeliki PLOMARITOGLOU ◽  
Efrosini BOUTOU ◽  
Neratzoula VASSILIADOU ◽  
Haralampos M. MOUTSOPOULOS ◽  
...  
Keyword(s):  
Rna Binding ◽  
Rna Binding Proteins ◽  
Peptide Mapping ◽  
Protein A ◽  
Major Protein ◽  
Protein Species ◽  
Two Dimensional Gel Electrophoresis ◽  
Heterogeneous Nuclear Ribonucleoprotein ◽  
Core Proteins ◽  
Nuclear Ribonucleoprotein

The structurally related A/B-type core heterogeneous nuclear ribonucleoprotein (hnRNP) polypeptides of 34–39 kDa (A1, A2, B1 and B2) belong to a family of RNA-binding proteins that are major components of 40 S hnRNP complexes. By two-dimensional gel electrophoresis and peptide mapping analysis we compared each member of the A/B-type core proteins in the human and rat liver cells. This comparison revealed the unique presence in rat cells of major protein species, referred to as mBx polypeptides, that appeared as three charge isoforms at a position corresponding to the minor HeLa B1b protein spot. In addition, clear differences in the ratios of the A1 polypeptide to the A1b isoform were observed. The detection, in sera of patients with rheumatic autoimmune diseases, of two novel autoantibody specificities, one recognizing solely B2 protein and the second both the B2 and mBx polypeptides, helped to identify mBx proteins as new A/B-type hnRNP components, immunologically related to B2 protein. A common immunoreactive V8 protease peptide of approx. 17 kDa has been identified in B2 and mBx hnRNP polypeptides. mBx protein species are identified in cells of murine origin, and have a ubiquitous tissue distribution and developmental appearance.

Nuclei that lack a lamina accumulate karyophilic proteins and assemble a nuclear matrix

1993 ◽  
Vol 106 (1) ◽  
pp. 275-285 ◽  
Author(s):  
H. Jenkins ◽  
T. Holman ◽  
C. Lyon ◽  
B. Lane ◽  
R. Stick ◽  
...  
Keyword(s):  
Dna Replication ◽  
Nuclear Matrix ◽  
Magnetic Beads ◽  
Major Protein ◽  
Two Dimensional Gel Electrophoresis ◽  
Nuclear Assembly ◽  
Egg Extracts ◽  
Nuclear Envelope Assembly ◽  
Protein Components

Xenopus egg extracts, which support nuclear assembly and DNA replication in vitro, were physically depleted of lamin B3 using monoclonal antibodies linked to magnetic beads. Depleted extracts were still able to support nuclear envelope assembly around demembranated sperm heads but the resulting pronuclei lacked a lamina and were unable to initiate semiconservative DNA replication or to assemble replicases, confirming previous data. Immunoblotting analysis of isolated nuclei and nuclear matrix fractions indicated that lamin-depleted nuclei still accumulated nucleoporins and PCNA. Furthermore, the rate of PCNA uptake was identical in lamin-depleted and control nuclei. However, neither the nucleoporins nor the PCNA was associated with nuclear matrix fractions. The major protein components of sperm pronuclear matrix fractions were characterized by two-dimensional gel electrophoresis. Of these proteins only three out of 22 species, other than the lamins, were significantly reduced in lamin-depleted nuclei, indicating that these nuclei do assemble a nuclear matrix.

scholarly journals Two Overlapping Domains of a Lyssavirus Matrix Protein That Acts on Different Cell Death Pathways

2010 ◽  
Vol 84 (19) ◽  
pp. 9897-9906 ◽  
Author(s):  
Florence Larrous ◽  
Alireza Gholami ◽  
Shahul Mouhamad ◽  
Jérôme Estaquier ◽  
Hervé Bourhy
Keyword(s):  
Cell Death ◽  
Amino Acid ◽  
Matrix Protein ◽  
Full Length ◽  
M Protein ◽  
Genotype 3 ◽  
Cell Death Pathways ◽  
Acid Fragment ◽  
M Proteins ◽  
Cellular Apoptosis

ABSTRACT The lyssavirus matrix (M) protein induces apoptosis. The regions of the M protein that are essential for triggering cell death pathways are not yet clearly defined. We therefore compared the M proteins from two viruses that have contrasting characteristics in terms of cellular apoptosis: a genotype 3 lyssavirus, Mokola virus (MOK), and a genotype 1 rabies virus isolated from a dog from Thailand (THA). We identified a 20-amino-acid fragment (corresponding to positions 67 to 86) that retained the cell death activities of the full-length M protein from MOK via both the tumor necrosis factor-related apoptosis-inducing ligand (TRAIL) and inhibition of cytochrome c oxidase (CcO) activity. We found that the amino acids at positions 77 and 81 have an essential role in triggering these two cell death pathways. Directed mutagenesis demonstrated that the amino acid at position 77 affects CcO activity, whereas the amino acid at position 81 affects TRAIL-dependent apoptosis. Mutations in the full-length M protein that compromised induction of either of these two pathways resulted in delayed apoptosis compared with the time to apoptosis for the nonmutated control.

Characterization of excretory–secretory products from protoscoleces of Echinococcus granulosus and evaluation of their potential for immunodiagnosis of human cystic echinococcosis

Parasitology ◽  
2004 ◽  
Vol 129 (3) ◽  
pp. 371-378 ◽  
Author(s):  
D. CARMENA ◽  
J. MARTÍNEZ ◽  
A. BENITO ◽  
J. A. GUISANTES
Keyword(s):  
Echinococcus Granulosus ◽  
Cystic Echinococcosis ◽  
Secretory Protein ◽  
Major Protein ◽  
Healthy Donors ◽  
Secretory Products ◽  
Protein Components ◽  
Human Cystic Echinococcosis

This study describes, for the first time, the characterization of excretory–secretory antigens (ES-Ag) from Echinococcus granulosus protoscoleces, evaluating their usefulness in the immunodiagnosis of human cystic echinococcosis. ES-Ag were obtained from the first 50 h maintenance of protoscoleces in vitro. This preparation contained over 20 major protein components which could be distinguished by 1-dimensional SDS–PAGE with apparent masses between 9 and 300 kDa. The culture of of protoscoleces from liver produced a greater variety of excretory–secretory protein components than those from lung. Determination of enzymatic activities of secreted proteins revealed the presence of phosphatases, lipases and glucosidases, but no proteases. These findings were compared to those obtained from somatic extracts of protoscoleces and hydatid cyst fluid products. Immunochemical characterization was performed by immunoblotting with sera from individuals infected by cystic echinococcosis (n=15), non-hydatidic parasitoses (n=19), various liver diseases (n=24), lung neoplasia (n=16), and healthy donors (n=18). Antigens with apparent masses of 89, 74, 47/50, 32, and 20 kDa showed specificity for immunodiagnosis of human hydatidosis. The 89 and 74 kDa components corresponded to antigens not yet described in E. granulosus, whereas proteins of 41–43 kDa and 91–95 kDa were recognized by the majority of the non-hydatid sera studied.

scholarly journals Purification and characterization of a uterine retinol-binding protein in the bitch

1995 ◽  
Vol 311 (2) ◽  
pp. 407-415 ◽  
Author(s):  
W C Buhi ◽  
I M Alvarez ◽  
V M Shille ◽  
M J Thatcher ◽  
J P Harney ◽  
...  
Keyword(s):  
Amino Acid ◽  
Dna Sequences ◽  
Binding Protein ◽  
Amino Acid Content ◽  
Amino Acid Sequences ◽  
Retinol Binding Protein ◽  
Total Amino Acid ◽  
Major Protein ◽  
Serum Retinol ◽  
Two Dimensional Gel Electrophoresis

A major canine endometrial secreted protein (cP6, 23,000-M(r)) was purified by ion-exchange and gel-filtration chromatography and characterized by two-dimensional gel electrophoresis. Anti-[human retinol-binding protein (hRBP)] serum identified cP6 on immunoblot analysis and immunoprecipitated cP6 from culture medium. This major protein was also shown to bind [3H]retinol. N-terminal and internal amino acid sequences were determined and compared with previously identified protein, RNA, or DNA sequences. N-terminal analysis revealed that cP6 had high identity and similarity to serum retinol-binding proteins (RBPs), while internal sequence analysis showed a strong similarity to rat androgen-dependent epididymal protein and beta-lactoglobulins. Amino acid analysis, however, showed significant differences between these proteins and cP6 in both total amino acid content and certain selected amino acids. Immunohistochemical analysis showed staining for RBP only in the uterine luminal epithelium. These studies suggest that bitch endometrium secretes a family of proteins (cP6), some of which bind [3H]retinol, are immunologically related to the RBP family, and have N-terminal and internal sequences with a high similarity to RBP, beta-lactoglobulins and other members of the lipocalin family. This family of proteins may be important in early development for supplying retinol or derivatives to the developing embryo.

Developmental expression of fibrillarin and U3 snRNA in Xenopus laevis

Development ◽  
1991 ◽  
Vol 112 (1) ◽  
pp. 317-326
Author(s):  
M. Caizergues-Ferrer ◽  
C. Mathieu ◽  
P. Mariottini ◽  
F. Amalric ◽  
F. Amaldi
Keyword(s):  
Ribosomal Rna ◽  
Rna Processing ◽  
Protein Detection ◽  
Developmental Expression ◽  
Oocyte Growth ◽  
Small Nuclear Ribonucleoprotein ◽  
Hybridization Probes ◽  
Ribosomal Rna Processing ◽  
Protein Components ◽  
Nuclear Ribonucleoprotein

Fibrillarin is one of the protein components that together with U3 snRNA constitute the U3 snRNP, a small nuclear ribonucleoprotein particle involved in ribosomal RNA processing in eucaryotic cells. Using an antifibrillarin antiserum for protein detection and a fibrillarin cDNA and a synthetic oligonucleotide complementary to U3 snRNA as hybridization probes, the expression of these two components has been studied during Xenopus development. Fibrillarin mRNA is accumulated early in oogenesis, like many other messengers, and translated during oocyte growth. Fibrillarin protein is thus progressively accumulated throughout oogenesis to be assembled with U3 snRNA and used for ribosome production in the amplified nucleoli. After fertilization, the amount of U3 snRNA decreases while the maternally accumulated fibrillarin mRNA is maintained and utilized to produce more protein. After the mid-blastula transition, stored fibrillarin is assembled with newly synthesized U3 snRNA and becomes localized in the prenucleolar bodies and reforming nucleoli.

Stage-specific patterns of collagen gene expression during development of Caenorhabditis elegans

1985 ◽  
Vol 5 (2) ◽  
pp. 363-372
Author(s):  
G N Cox ◽  
D Hirsh
Keyword(s):  
Caenorhabditis Elegans ◽  
Protein Composition ◽  
Large Family ◽  
Major Protein ◽  
Mrna Levels ◽  
Mrna Accumulation ◽  
C Elegans ◽  
Collagen Protein ◽  
Protein Components ◽  
Collagen Genes

Collagens are the major protein components of the Caenorhabditis elegans cuticle and are encoded by a large family of 40 to 150 closely related but nonidentical genes. We have determined temporal patterns of mRNA accumulation for a large number of collagen genes by screening recombinant phages and plasmids containing cloned collagen genes under high stringency conditions with 32P-labeled cDNA preparations specific for eggs or three postembryonic molts. We find that collagen mRNA levels are regulated both temporally and quantitatively during C. elegans development. Most genes studied exhibit one of four patterns of mRNA accumulation which correlate with changes in cuticle morphology and collagen protein composition during development. Our results suggest that, in general, there is a progressive activation of new collagen genes during normal development.

Protein composition of nuclear matrix preparations from HeLa cells: an immunochemical approach

1986 ◽  
Vol 80 (1) ◽  
pp. 103-122
Author(s):  
R. Verheijen ◽  
H. Kuijpers ◽  
P. Vooijs ◽  
W. van Venrooij ◽  
F. Ramaekers
Keyword(s):  
Nuclear Matrix ◽  
Connective Tissue Diseases ◽  
Protein Composition ◽  
Cytoskeletal Proteins ◽  
Two Dimensional ◽  
Two Dimensional Gel Electrophoresis ◽  
Core Proteins ◽  
Nuclear Rna ◽  
Hela S3 ◽  
Protein Components

Procedures for the isolation of HeLa S3 nuclear matrices were re-examined with special emphasis on the use of various nucleases and detergents as well as on the ionic strength of the final salt extraction. The protein composition of the resulting nuclear matrix preparations was analysed by one- and two-dimensional gel electrophoresis and found to be extremely reproducible. By means of co-electrophoresis several typical cytoskeletal proteins (actin, vimentin and cytokeratins) and heterogeneous nuclear RNA (hnRNA)-associated core proteins (hnRNP) were shown to be present in such nuclear matrix preparations. The nature of some other protein components was elucidated using two-dimensional immunoblotting and immunofluorescence. For this purpose mouse monoclonal antibodies to cytoskeletal components (vimentin, cytokeratins), small nuclear RNP (70 X 10(3) Mr protein of U1-RNP), hnRNP (C1/C2) and the pore-complex lamina (lamins A, B and C) were used next to human autoimmune sera obtained from patients with connective tissue diseases and directed against the residual nucleoli and the internal fibrillar mass. These antibodies enabled us to identify a number of proteins present specifically in the nuclear matrix and to show that part of the cytoskeletal proteins are still present in the isolated structures.

Sign in / Sign up

Export Citation Format

Share Document