Nuclear proteins are a protein found in the nucleus. Proteins are transported in the nucleus by means of a nuclear pore complex, which acts as a barrier between the cytoplasm and the nuclear membrane. Protein import and export through the nuclear pore complex plays a fundamental role in gene regulation and other biological functions. Nuclear proteins generally contain special amino acid signal sequences that function as proteins for localization and localization. Nucleus proteins are a class of binding proteins. A special form of protein that is ubiquitous in the nucleus of various organisms, and the nucleic acid binds to a basic protein such as histone or protamine to become a main component of the nucleus. Depending on the type of nucleic acid, it can be divided into ribonucleic acid nuclear protein and deoxyribonucleic acid nuclear protein.
Nuclear protein is a class of binding proteins. A special form of protein that is ubiquitous in the nucleus of various organisms, and the nucleic acid binds to a basic protein such as histone or protamine to become a main component of the nucleus. Depending on the type of nucleic acid, it can be divided into ribonucleic acid nuclear protein and deoxyribonucleic acid nuclear protein. It can be extracted from the nucleus and can be dissolved in a 1 mol/L NaCl solution. Proteins in nuclear proteins include histone (or protamine) and non-histone proteins. Histones contain basic amino acids such as arginine and lysine, which are positively charged. Protamine is only found in eukaryotic cells and contains more acidic amino acids such as aspartic acid and glutamic acid. It is an acidic protein with a negative charge. Nuclear proteins play a decisive role in genetics and protein synthesis, and are the only components of certain viruses and their bacteriophages in organisms.
Karyophilic protein is a type of protein that, when synthesized in the cytoplasm, needs or can enter the nucleus to function. Nuclear localization sequence: nucleophilic proteins generally contain special amino acid sequences. These short peptides ensure that the entire protein can be transported into the nucleus through the nuclear pore complex. The sequence of "positioning" action is called a nuclear localization sequence. Nuclear output signal (NES): A signal that outputs nuclear nuclei as a nuclear material, helping certain molecules in the nucleus to rapidly enter the cytoplasm through the nucleus, and are located in the nucleus and then transported to the cytoplasmic molecules.
Figure 1. Process of protein synthesis.
The process of synthesizing a polypeptide chain by using mRNA as a template for activated amino acids on ribosomes. The form of protein synthesis refers to the process in which ribosome size subunits are combined to form ribosomes when needed, and proteins are disintegrated after synthesis and recombined to form ribosomes when needed. Most generalized ribosome cycle refers to the process of condensing a nucleoprotein onto a ribosome to form a polypeptide chain. This process involves the initiation of peptide chain synthesis, the extension of the peptide chain, and the termination of peptide chain synthesis. Release, narrowly defined ribosome cycle refers to the peptide chain elongation phase during the synthesis of the polypeptide chain, which is carried out by the carry, peptide and translocation cycles in three steps until the termination phase.
Nuclear protein in the virus
A class of complex proteins that combine proteins and nucleic acids. Exist in all creatures. Viruses are a very simple class of organisms whose chemical nature is nuclear proteins. Nuclear proteins in cells are mainly found in chromosomes and ribosomes. Since nucleic acids have DNA RNA, nuclear proteins are thus classified into DNA-nuclear proteins and RNA-nuclear proteins. DNA-nuclear proteins are mainly found in the nucleus, and RNA-nuclear proteins are mainly present in ribosomes. Many of the two types of nuclear proteins have similar physicochemical properties, can be dyed by basic dyes, are unstable, and are easily decomposed into nucleic acids and proteins under the action of heat or alkali.
Ribonucleoprotein (RNP) refers to a nuclear protein containing RNA, a form in which nucleic acids and proteins are combined. Ribonucleoproteins include ribosomes, telomerase, and small nuclear RNP (snRNP). RNP plays an important role in the replication of influenza A. Ribosomes are also known as ribosome and ribonucleoprotein. A subcellular nuclear protein particle consisting of approximately equal amounts of ribonucleic acid (RNA, 35% to 55%) and protein (45% to 65%). It is a place for protein synthesis in cells. Multiple ribosomes can be joined in a string to form a polyribosome. Each ribonucleoprotein body is approximately spherical in shape and has a diameter of about 20 nm. It consists of two different subunits (large subunit and small subunit), which are non-covalently bonded by magnesium ions and other bonds. Four classes of ribonucleoprotein bodies have been identified: bacteria, plants, animals, and mitochondria, which are distinguished by their sedimentation coefficients for monomeric, subunit, and ribonucleoprotein RNA. The ribosome has two sites that bind to the transfer RNA (A and P) and can be attached to messenger RNA, (Rb).
Alpha-synuclein is a soluble protein expressed in the presynaptic system of the central nervous system and is closely related to the pathogenesis of Parkinson's disease. Alpha-synuclein is abnormally expressed and aggregated under the influence of various physiological and environmental factors. Through a series of biochemical reactions such as oxidative stress, it produces toxic effects on neurons and participates in the occurrence of Parkinson's disease. The understanding and research on the chemical nature of α-synuclein, the mechanism of aggregation and its influencing factors will be very beneficial to the prevention and treatment of Parkinson's disease. Alpha-synuclein is a soluble protein widely distributed in the brain tissue of healthy people. It is the most important protein in the pathogenesis of Parkinson's disease, because it is the main structural component of Lewy bodies, and α-synuclein aggregation is closely related to the formation of Lewy bodies and the death of dopaminergic neurons.
1. Freitas N.; et al. Mechanisms and signals for the nuclear import of proteins. Current Genomics. 2009,10 (8): 550–557.