Nuclear matrix
Encyclopedia
In biology
, the nuclear matrix is the network of fibres found throughout the inside of a cell nucleus
and is somewhat analogous to the cell cytoskeleton
. However, in contrast to the cytoskeleton, the nuclear matrix has been proposed to be a highly dynamic structure, perhaps more like a dynamic sponge with open compartments for free diffusion of molecules in the nucleus.
The exact function of this matrix is still disputed, and its very existence has recently been called into question. There is evidence that the nuclear matrix is involved in regulation of gene expression
in Arabidopsis thaliana
.
chromosomes at interphase
, may be maintained due to steric hindrance or electrostatic repulsion forces between the apparently highly structured CT surfaces, this concept has to be reconciled with observations according to which cells treated with the classical matrix-extraction procedures maintain defined territories up to the point where a minor subset of acidic nuclear matrix proteins is released – very likely those proteins that governed their association with the nuclear skeleton.
S/MARs (scaffold/matrix attachment elements), the DNA regions that are thought to attach genomic DNA to the nuclear skeleton, show an ever increasing spectrum of established biological activities. All these activities are in agreement with (or most easily explained by) the nuclear matrix hypothesis. This is one justification for maintaining this concept before equally plausible alternative models emerge.
S/MARs find increasing use for the rational design of vectors
with widespread use in gene therapy
and biotechnology
. Nowadays S/MAR functions can be modulated, improved and custom-tailored to the specific needs of novel vector systems.
Biology
Biology is a natural science concerned with the study of life and living organisms, including their structure, function, growth, origin, evolution, distribution, and taxonomy. Biology is a vast subject containing many subdivisions, topics, and disciplines...
, the nuclear matrix is the network of fibres found throughout the inside of a cell nucleus
Cell nucleus
In cell biology, the nucleus is a membrane-enclosed organelle found in eukaryotic cells. It contains most of the cell's genetic material, organized as multiple long linear DNA molecules in complex with a large variety of proteins, such as histones, to form chromosomes. The genes within these...
and is somewhat analogous to the cell cytoskeleton
Cytoskeleton
The cytoskeleton is a cellular "scaffolding" or "skeleton" contained within a cell's cytoplasm and is made out of protein. The cytoskeleton is present in all cells; it was once thought to be unique to eukaryotes, but recent research has identified the prokaryotic cytoskeleton...
. However, in contrast to the cytoskeleton, the nuclear matrix has been proposed to be a highly dynamic structure, perhaps more like a dynamic sponge with open compartments for free diffusion of molecules in the nucleus.
The exact function of this matrix is still disputed, and its very existence has recently been called into question. There is evidence that the nuclear matrix is involved in regulation of gene expression
Gene expression
Gene expression is the process by which information from a gene is used in the synthesis of a functional gene product. These products are often proteins, but in non-protein coding genes such as ribosomal RNA , transfer RNA or small nuclear RNA genes, the product is a functional RNA...
in Arabidopsis thaliana
Arabidopsis thaliana
Arabidopsis thaliana is a small flowering plant native to Europe, Asia, and northwestern Africa. A spring annual with a relatively short life cycle, arabidopsis is popular as a model organism in plant biology and genetics...
.
Justification of the Nuclear Matrix Hypothesis
For a long time the question whether a polymer meshwork, a “nuclear matrix” or “nuclear-scaffold” is an essential component of the in vivo nuclear architecture has remained a matter of debate. While there are arguments that the relative position of chromosome territories (CTs), the equivalent of condensed metaphaseMetaphase
Metaphase, from the ancient Greek μετά and φάσις , is a stage of mitosis in the eukaryotic cell cycle in which condensed & highly coiled chromosomes, carrying genetic information, align in the middle of the cell before being separated into each of the two daughter cells...
chromosomes at interphase
Interphase
Interphase is the phase of the cell cycle in which the cell spends the majority of its time and performs the majority of its purposes including preparation for cell division. In preparation for cell division, it increases its size and makes a copy of its DNA...
, may be maintained due to steric hindrance or electrostatic repulsion forces between the apparently highly structured CT surfaces, this concept has to be reconciled with observations according to which cells treated with the classical matrix-extraction procedures maintain defined territories up to the point where a minor subset of acidic nuclear matrix proteins is released – very likely those proteins that governed their association with the nuclear skeleton.
S/MARs (scaffold/matrix attachment elements), the DNA regions that are thought to attach genomic DNA to the nuclear skeleton, show an ever increasing spectrum of established biological activities. All these activities are in agreement with (or most easily explained by) the nuclear matrix hypothesis. This is one justification for maintaining this concept before equally plausible alternative models emerge.
S/MARs find increasing use for the rational design of vectors
Vector (molecular biology)
In molecular biology, a vector is a DNA molecule used as a vehicle to transfer foreign genetic material into another cell. The four major types of vectors are plasmids, viruses, cosmids, and artificial chromosomes...
with widespread use in gene therapy
Gene therapy
Gene therapy is the insertion, alteration, or removal of genes within an individual's cells and biological tissues to treat disease. It is a technique for correcting defective genes that are responsible for disease development...
and biotechnology
Biotechnology
Biotechnology is a field of applied biology that involves the use of living organisms and bioprocesses in engineering, technology, medicine and other fields requiring bioproducts. Biotechnology also utilizes these products for manufacturing purpose...
. Nowadays S/MAR functions can be modulated, improved and custom-tailored to the specific needs of novel vector systems.
- See also: minicircleMinicircleMinicircles are small circular plasmid derivatives that have been freed from all prokaryotic vector parts.For uses as transgene carriers for the genetic modification of mammalia cells, their preparation usually follows a two-step procedure:...