Illustrate the functions of various small non coding RNAs

Small intranuclear RNA: located in the nucleus.

There are 5 kinds of SNRNA, called U1, U2, U4, U5, and U6, which form complexes with a variety of proteins and participate in the intron processing and splicing of HNRNA in eukaryotic cells.

Nucleolus. Small RNAs: localized to the nucleolus and mainly involved in RNA processing and modification, such as the methylation of ribose C-2' in RRNA.

Cytosolic small RNA: present in the cytoplasm.

, involved in the formation of signal-recognition particles that guide proteins containing signal peptides into the endoplasmic reticulum.

Localization compositing. Catalytic small RNA: also known as ribozyme, is a class of small RNA molecules with catalytic functions in cells

It has the activity to catalyze the degradation of specific RNAs and plays an important role in the splicing modification of RNA.

Small interfering RNA

Cleavage of double-stranded RNA expressed by an exogenous invasive gene by an organism host results in a small fragment of RNA with a specific length and sequence. These siRNAs can bind to exogenous gene-expressing mRNAs in single-stranded form and induce corresponding mRNA degradation.

MicroRNAs: A class of endogenous genes with a length of about 22 nt selectively regulates the expression of genes by binding to mRNA.

RNA is a type of enzyme that can speed up the reaction of a substance in this example.

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Analysis: Non-coding RNA refers to RNA that is not translated into proteins, such as tRNA, rRNA, etc., which are not translated into proteins, but are involved in the protein translation process.

In addition, snRNA, snorna, etc. are involved in RNA splicing and RNA modification, and miRNA is also non-coding RNA, which is a small RNA molecule that complements the transcribed gene and mediates gene silencing.

gRNA, also known as guide RNA, is the RNA involved in RNA in eukaryotes that has a complementary sequence to mRNA;

ERNA, an RNA molecule transcribed from endogens or non-coding DNA, finely regulates the transcription and translation efficiency of genes;

Signal recognition granular RNA, which is recognized in the cytoplasm with signal peptide-containing mRNA and determines the secreted RNA functional molecule;

PRNA, bacteriophage RNA, Fi29 phage with 6 identical small RNA molecules using ATP to participate in DNA packaging;

tmRNA, RNA with tRNA-like and mRNA-like complexes, is ubiquitous in bacteria to identify ribosomes that are incorrectly translated or code-read, as well as those that are delayed and stopped, mediating the disintegration of these problematic ribosomes;

Finally, there is the untranslated region of the mRNA, which contains ribosomal recognition elements such as 5'-utr,3'- utr, etc. Introns can also be considered as non-coding RNAs.

RNA can be divided into the following according to its structure and function

1) Transport ribonucleic acid (tRNA), the main function of tRNA is to transport amino acids in protein biosynthesis, that is, to transport amino acids from the cytosol to the nucleoproteosome or polynucleosomes bound to mRNA, and make it form a complementary combination with the codon in the mRNA molecule, so as to accurately produce various amino acid raw materials that are needed when the peptide chain is generated.

2) The function of mRNA is to act as a template for translating proteins, and they directly determine what kind of protein is synthesized in biology.

3) Nucleosome ribonucleic acid (RRNA), rRNA They do not exist alone in the cytoplasm, but bind to a variety of small protein molecules to nucleosome existence and perform functions.

Answer] :(1) RNA plays a decisive role in the translation of genetic information.

Protein biosynthesis is the simplest and most important metabolic process in living organisms, and the three types of RNA share and complete this process. RNA plays the role of assembly and catalysis, tRNA plays the role of transport and information transversion, and mRNA plays the role of messenger and template.

2) RNA has important catalytic functions and other housekeeping functions.

Most nucleic acids in nature catalyze intramolecular reactions, and they are a way of post-processing of RNA, including self-shearing, self-splicing, and self-catalysis.

3) Post-transcriptional processing and modification of RNA rely on various types of small RNAs and their protein complexes.

The processing of RNA transcription is very complex, including cutting, pruning, modification, isomerism, addition, splicing, and recoding, and other processes, except for a few relatively simple processes that can be completed directly by enzymes, usually with some special RNA involvement.

4) RNA plays an important role in regulating gene expression and cell function.

Antisense repatriation RNA can bind to the target sequence by complementing it, or directly prevent its function or change the target site conception to affect its function.

5) RNA plays an important role in biological evolution.

The discovery of ribozymes suggests that RNA is both an information molecule and a functional molecule, and RNA may have been the first to appear in the early days of life. From the splicing process of RNA, we can infer the evolutionary process of protein and its gene module construction. Splicing can eliminate the harm of genetic mutations, increase the diversity of genetic information, and promote biological evolution.

RNA may also be the molecular basis for some acquired inheritance.

The circRNA molecule has a closed circular structure and does not have 5'- End and 3'-end, so it is not affected by RNA exonuclease, the expression is more stable, and it is not easy to degrade. circrna is almost entirely localized toin the nucleus。CircRNAs are highly conserved in sequences.

Due to the end-to-end attachment of circRNAs, there is no tail, so circRNAs are easily discarded in the traditional isolation process. This is the main reason why circrna-straight has not been discovered before. These circRNA molecules are rich in miRNA binding sites, which act as miRNA sponges in cells, and by binding miRNAs, they can relieve the inhibition of miRNAs on their target genes and increase the expression level of target genes, which is called the competing endogenous RNA (CERNA) mechanism.

Definitions:Long non-coding RNAs are a class of RNA that is of a length ofnucleotides of RNA molecules. NcRNA is transcribed by RNA polymerase I and cleaved to form a structure similar to mRNA.

The lncRNA has a poly(A) tail and promoter, but there is no readable frame in the sequence. LNcrRNA can be used in DNA sequences between protein-coding genes, pseudogenes, and protein-coding genes. LNcrRNAs localize within the nucleus and within the cytoplasm.

Mechanism of action:

Non-coding RNAModulation of mRNA stability through RNA interference pathways: miRNAs are a non-coding type of RNA whose sequence is complementarially paired with the 3'UTR of its target mRNA, which can lead to degradation of the mRNA, resulting in a decrease in the template for mRNA translation and a decrease in the level of naturally occurring proteins.

RISC specifically binds to the homology region of mRNA expressed by exogenous genes, and RISC has the function of nuclease to cleave mRNA at the binding site, and the cleavage site is the two ends that complement the antisense strand in the sirna. The cleaved mRNA is then downgraded, which induces a degradation response by the host cell to these mRNAs.

Abstract in ChineseRNA degradation is an important part of gene expression regulation. Au-rich element (ARE)-mediated degradation is a key way to regulate mRNA stability, which is precisely regulated by a variety of factors and mechanisms. TTP is an ARE binding protein that began to be studied earlier; It plays an important role in the regulation of RNA degradation and is related to the mRNA stability of several important immune or tumor-related genes.

This is the first thing to know about the difference between the genetic structure of prokaryotes and true and human organisms.

Prokaryotes: Consists of coding and non-coding regions, with RNA polymerase binding sites upstream of the non-coding regions. The coding area is contiguous and not spaced.

The DNA sequences in this region can all code for proteins, which are called coding sequences. The non-coding region is composed of DNA sequences that cannot code for proteins, called non-coding sequences.

Eukaryotes: Consists of coding and non-coding regions, with RNA polymerase binding sites upstream of the non-coding regions. The coding region is discontinuous, spaced, and consists of exons and introns.

The DNA sequences of exons can code for proteins, which are called coding sequences, while the DNA sequences of introns cannot code for proteins, and are called non-coding sequences. The non-coding region is composed of DNA sequences that cannot code for proteins, called non-coding sequences. Therefore, the non-coding sequences of eukaryotes contain sequences with introns and non-coding regions.

Note: When the coding region of eukaryotes encodes a protein, the entire coding region is transcribed to form mRNA, but the MRAN transcribed by introns cannot be translated into proteins, so it needs to be removed.

In summary, non-coding sequences refer to DNA sequences that do not code for proteins, such as sequences and introns with non-coding regions.

Non-coding RNA refers to RNA sequences that cannot be translated into proteins, such as mRNA transcribed from introns.

It doesn't seem to have any non-coding genes, if anything, that is, non-coding DNA sequences.

There are no non-coding genes, right?

A gene is equivalent to a coding sequence.

A non-coding sequence means that the sequence is not a gene and is not translated into a protein. However, non-coding sequences are not useless, and they can serve the coding gene and play an auxiliary role.

Non-coding RNA is RNA that cannot be translated into proteins, and these RNAs have other functions, such as being a transcription machine, and so on.