Nuclear skeleton

Grid structure composed of fibrin

This entry is missing Overview , add relevant content to make the entry more complete, and it can also be upgraded quickly. Hurry up edit Come on!

Nuclear matrix (nuclear matrix) or nuclear skeleton Eukaryotic cell Intranuclear network structure In a broad sense, the nuclear skeleton includes the nuclear matrix Nuclear fiber layer (or core fiber layer- Nuclear pore complex structural system ）, and Chromosome skeleton ； In the narrow sense, the nuclear skeleton only refers to the nuclear matrix, that is, in addition to Nuclear capsule , core fiber layer Chromatin and nucleolus Extraneous grid structure 。 Because the nuclear matrix and DNA replication ， RNA Transcription And processing, chromosome assembly and Viruses Copy, etc Life activities They are closely related, so they are increasingly valued.

Chinese name: Nuclear skeleton

Foreign name: nuclear matrix

catalog

form

Announce

edit

Nuclear skeleton

The nuclear skeleton is composed of fibrin Constitutive grid structure Its protein composition is reasonable Cytoskeleton Yes, there should be a nuclear skeleton. But only in the nuclear skeleton Keratin and Muscle protein Components, in some protozoan The nuclear skeleton also contains microtubule 。 At the same time, there is a small amount of RNA in the nuclear skeleton, which can maintain the three-dimensional nuclear skeleton network structure The integrity of is required. stay Evolutionary trend Look, the composition of nuclear skeleton is from diversification to singleness and specialization.

Composition of nuclear matrix

Announce

edit

Nuclear matrix The composition of is relatively complex, and the main components can be divided into three categories: ① Nonhistone nature fibrin , molecular weight 40-60KD, accounting for more than 96%, of which a considerable part is Sulfur-containing protein Its disulfide bond has a maintenance nuclear skeleton Structural integrity The role of; In addition to fibrin, there are more than 10 secondary protein , including Actin and Vimentin The latter forms the outer cover of the nuclear skeleton; There are also three types of nuclear skeleton fragments Scaffold protein (scaffold proteins, SC Ⅰ, SC Ⅱ, SC Ⅲ), the function of SC Ⅱ, Ⅲ is not clear, and SC Ⅰ is DNA topoisomerase Ⅱ. ② A small amount of RNA and DNA three-dimensional structure DNA is required, and DNA is called matrix/scaffold associated region (MAR or SAR), which is usually an AT rich region. ③ A small amount of phospholipids (1.6%) and sugars (0.9%).

The nuclear skeleton fibers are different in thickness, with a diameter of 3-30nm, forming a three-dimensional network structure Nuclear fiber layer , and Nuclear pore complex Connect Chromatin and nucleolus The network is in it. Core skeleton core fiber layer- Intermediate fibre The three are connected to form a unity between the core and the essence Network system 。 This system is more than microtubule Microfilament It has higher stability.

Function of nuclear skeleton

Announce

edit

1. For dna replication Provide support, DNA It is anchored on the nuclear skeleton in the form of a replication ring. The nuclear skeleton has enzymes needed for DNA replication, such as: DNA Polymerase α 、 DNA primer enzyme DNA topoisomerase II, etc. DNA Autocopy Sequence (ARS) is also bound to the nuclear skeleton.

2. Yes Gene transcription Processing place, RNA The transcription of RNA polymerase Of binding site RNA is synthesized on the nuclear skeleton. The newly synthesized RNA is also bound to the nuclear skeleton, where it is processed and modified.

3. It is related to chromosome construction. It is generally believed that the nuclear skeleton is related to Chromosome skeleton It is the same kind of substance, 30nm Chromatin fibre It is combined on the nuclear skeleton to form radiation annular Structure of, in Fission period Further packaged into optical microscope Chromosomes visible below

Novice on the road

Growth task Getting Started with Editing Edit Rule Edit by myself

I have questions

Content query Online Service Official post bar Feedback

Complaints and suggestions

Report bad information Failed to appeal through entries Complaint of infringement information Blocking query and unblocking

Jinggong Network Anbei No. 1100000200001