scholarly journals Experimental observations of a nuclear matrix

2001 ◽  
Vol 114 (3) ◽  
pp. 463-474 ◽  
Author(s):  
J. Nickerson
Keyword(s):  
Nuclear Matrix ◽  
Spatial Organization ◽  
Biochemical Characterization ◽  
Nuclear Lamina ◽  
Matrix Proteins ◽  
Combined Application ◽  
Structural Biochemistry ◽  
10 Nm Filaments ◽  
Loop Domains

Nuclei are intricately structured, and nuclear metabolism has an elaborate spatial organization. The architecture of the nucleus includes two overlapping and nucleic-acid-containing structures - chromatin and a nuclear matrix. The nuclear matrix is observed by microscopy in live, fixed and extracted cells. Its ultrastructure and composition show it to be, in large part, the ribonucleoprotein (RNP) network first seen in unfractionated cells more than 30 years ago. At that time, the discovery of this RNP structure explained surprising observations that RNA, packaged in proteins, is attached to an intranuclear, non-chromatin structure. Periodic and specific attachments of chromatin fibers to the nuclear matrix create the chromatin loop domains that can be directly observed by microscopy or inferred from biochemical experiments. The ultrastructure of the nuclear matrix is well characterized and consists of a nuclear lamina and an internal nuclear network of subassemblies linked together by highly structured fibers. These complex fibers are built on an underlying scaffolding of branched 10-nm filaments that connect to the nuclear lamina. The structural proteins of the nuclear lamina have been well characterized, but the structural biochemistry of the internal nuclear matrix has received less attention. Many internal matrix proteins have been identified, but far less is known about how these proteins assemble to make the fibers, filaments and other assemblies of the internal nuclear matrix. Correcting this imbalance will require the combined application of biochemistry and electron microscopy. The central problem in trying to define nuclear matrix structure is to identify the proteins that assemble into the 10-nm filaments upon which the interior architecture of the nucleus is constructed. Only by achieving a biochemical characterization of the nuclear matrix will we advance beyond simple microscopic observations of structure to a better understanding of nuclear matrix function, regulation and post-mitotic assembly.

scholarly journals Biochemical Characterization of Major Bone-Matrix Proteins Using Nanoscale-Size Bone Samples and Proteomics Methodology

2011 ◽  
Vol 10 (9) ◽  
pp. M110.006718 ◽  
Author(s):  
Grażyna E. Sroga ◽  
Lamya Karim ◽  
Wilfredo Colón ◽  
Deepak Vashishth
Keyword(s):  
Biochemical Characterization ◽  
Bone Matrix ◽  
Matrix Proteins ◽  
Bone Matrix Proteins

Biochemical Characterization of Chlorophyll-Free Mitochondria From Pea Leaves

1985 ◽  
Vol 12 (3) ◽  
pp. 219 ◽  
Author(s):  
DA Day ◽  
M Neuburger ◽  
R Douce
Keyword(s):  
Biochemical Characterization ◽  
Membrane Integrity ◽  
Phospholipid Composition ◽  
Respiratory Control ◽  
Matrix Proteins ◽  
Green Leaf ◽  
Protein Ratio ◽  
Linear Gradient ◽  
The Matrix

Mitochondria from pea leaves were purified by centrifugation on a self-generated Percoll gradient which contained a linear gradient of polyvinylpyrrolidone-25 (0-10%, w/v). The chlorophyll content of the purified mitochondria was less than 1 �g per mg protein. All substrates were rapidly oxidized by these mitochondria, the rate of glycine oxidation being between 200 and 300 nmol O2 min-1 mg-1 protein, depending on the age of the leaves used. These rates did not vary significantly over a period of 20 h, provided NAD+ was supplied exogenously, when the mitochondria were stored on ice. Respiratory control, ADP/O ratios and outer membrane integrity (always more than 95%) were also maintained during storage. The phospholipid composition of the membranes from the leaf mitochondria was virtually identical to that of mitochondria from non-photosynthetic tissues although their lipid to protein ratio was slightly lower. The polypeptide pattern of the membranes from green leaf mitochondria and those from etiolated leaves and hypocotyls were also similar, but marked differences were observed between the matrix proteins from the different tissues. In particular, intensely stained bands at 94, 51,41 and 15.5 kDa which were present in the matrix of green leaf mitochondria were missing or present in much smaller quantities in the non-photosynthetic tissues. This difference was correlated with the ability of the mitochondria to oxidize glycine, suggesting that the four polypeptides may be associated with the glycine decarboxylase complex.

scholarly journals Association of Chromosome Territories with the Nuclear Matrix

1999 ◽  
Vol 146 (3) ◽  
pp. 531-542 ◽  
Author(s):  
Hong Ma ◽  
Alan J. Siegel ◽  
Ronald Berezney
Keyword(s):  
Nuclear Matrix ◽  
Nuclear Lamina ◽  
Chromosome Territory ◽  
Matrix Proteins ◽  
Small Subset ◽  
Chromosome Territories ◽  
Nuclear Matrix Proteins ◽  
Dispersive Effect ◽  
Replication Sites ◽  
Normal Human

To study the possible role of the nuclear matrix in chromosome territory organization, normal human fibroblast cells are treated in situ via classic isolation procedures for nuclear matrix in the absence of nuclease (e.g., DNase I) digestion, followed by chromosome painting. We report for the first time that chromosome territories are maintained intact on the nuclear matrix. In contrast, complete extraction of the internal nuclear matrix components with RNase treatment followed by 2 M NaCl results in the disruption of higher order chromosome territory architecture. Correlative with territorial disruption is the formation of a faint DNA halo surrounding the nuclear lamina and a dispersive effect on the characteristically discrete DNA replication sites in the nuclear interior. Identical results were obtained using eight different human chromosome paints. Based on these findings, we developed a fractionation strategy to release the bulk of nuclear matrix proteins under conditions where the chromosome territories are maintained intact. A second treatment results in disruption of the chromosome territories in conjunction with the release of a small subset of acidic proteins. These proteins are distinct from the major nuclear matrix proteins and may be involved in mediating chromosome territory organization.

Characterization of the nuclear matrix proteins in a transgenic mouse model for prostate cancer

2002 ◽  
Vol 86 (2) ◽  
pp. 203-212 ◽  
Author(s):  
Eddy S. Leman ◽  
Julie A. Arlotti ◽  
Rajiv Dhir ◽  
Norman Greenberg ◽  
Robert H. Getzenberg
Keyword(s):  
Prostate Cancer ◽  
Mouse Model ◽  
Transgenic Mouse ◽  
Nuclear Matrix ◽  
Transgenic Mouse Model ◽  
Matrix Proteins ◽  
Nuclear Matrix Proteins

Preliminary immunohistochemical characterization of a monoclonal antibody (pro:4-216) prepared from human prostate cancer nuclear matrix proteins

Urology ◽  
1997 ◽  
Vol 50 (5) ◽  
pp. 800-808 ◽  
Author(s):  
Alan W. Partin ◽  
Joseph V. Briggman ◽  
Eric N.P. Subong ◽  
Robert Szaro ◽  
Ana Oreper ◽  
...  
Keyword(s):  
Prostate Cancer ◽  
Monoclonal Antibody ◽  
Nuclear Matrix ◽  
Matrix Proteins ◽  
Human Prostate ◽  
Human Prostate Cancer ◽  
Nuclear Matrix Proteins

Characterization of some nuclear matrix proteins in maize

Plant Science ◽  
1993 ◽  
Vol 91 (1) ◽  
pp. 35-43 ◽  
Author(s):  
Maria Ivanchenko ◽  
Bistra Tasheva ◽  
Lubomir Stoilov ◽  
Rositsa Christova ◽  
Jordanka Zlatanova
Keyword(s):  
Nuclear Matrix ◽  
Matrix Proteins ◽  
Nuclear Matrix Proteins

Nucleoskeltal proteins with bifunctional roles in the nucleus and mitotic apparatus: a paradigm for protein dynamics in the cell cycle

1995 ◽  
Vol 53 ◽  
pp. 770-771
Author(s):  
B. R. Brinkley ◽  
D. He ◽  
C. Zeng ◽  
B. Scott ◽  
D. Turner
Keyword(s):  
Nuclear Matrix ◽  
Hormone Receptors ◽  
Nuclear Lamina ◽  
Eukaryotic Cell ◽  
Matrix Proteins ◽  
Mitotic Apparatus ◽  
Nuclear Compartment ◽  
Nuclear Matrix Proteins ◽  
Intact Nucleus ◽  
Nuclease Digestion

The eukaryotic cell nucleus, once believed to contain structureless nucleoplasm surrounding chromatin and the nucleolus is now thought to contain an extensive nucleoskeletal matrix on which chromatin, RNP and a complex array of transcription factors, hormone receptors and other regulatory factors are spatially arranged. A distinct nucleoskeleton has been difficult to identify in the intact nucleus, due in part to masking by a dense array of chromatin fibers. However, if chromatin is extracted by nuclease digestion and high salt, an underlying anastomosing network of 9-13 nm core filaments can be demonstrated. The nucleoskeleton resembles the cytoplasmic intermediate filament complex but is confined entirely within the nucleus where it connects the nuclear lamina with various nuclear organelles, forming an integral lattice of fibers collectively called the nuclear matrix. Although the molecular composition of the nucleoskeleton remains elusive, its integrity apparently requires RNP and a growing list of nuclear matrix proteins.Although relatively insoluble within the nuclear compartment, the entire nucleoskeletal framework and associated chromatin is efficiently dismantled, packaged, partitioned and reassembled into daughter nuclei during mitosis.

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