Oligonucleotides are short DNA or RNA molecules, oligomers, that have a wide range of applications in genetic testing, research, and forensics. Commonly made in the laboratory by solid-phase chemical synthesis, these small bits of nucleic acids can be manufactured as single-stranded molecules with any user-specified sequence, and so are vital for artificial gene synthesis, polymerase chain reaction (PCR), DNA sequencing, library construction and as molecular probes. In nature, oligonucleotides are usually found as small RNA molecules that function in the regulation of gene expression, or are degradation intermediates derived from the breakdown of larger nucleic acid molecules.
Gene silencing is the regulation of gene expression in a cell to prevent the expression of a certain gene. Gene silencing can occur during either transcription or translation and is often used in research. In particular, methods used to silence genes are being increasingly used to produce therapeutics to combat cancer and diseases, such as infectious diseases and neurodegenerative disorders.
Antisense therapy is a form of treatment for genetic disorders or infections. When the genetic sequence of a particular gene is known to be causative of a particular disease, it is possible to synthesize a strand of nucleic acid that will bind to the messenger RNA (mRNA) produced by that gene and inactivate it, effectively turning that gene "off". This is because mRNA has to be single stranded for it to be translated. Alternatively, the strand might be targeted to bind a splicing site on pre-mRNA and modify the exon content of an mRNA.
Antisense RNA (asRNA), also referred to as antisense transcript, natural antisense transcript (NAT) or antisense oligonucleotide, is a single stranded RNA that is complementary to a protein coding messenger RNA (mRNA) with which it hybridizes, and thereby blocks its translation into protein. asRNAs have been found in both prokaryotes and eukaryotes, antisense transcripts can be classified into short and long non-coding RNAs (ncRNAs). The primary function of asRNA is regulating gene expression. asRNAs may also be produced synthetically and have found wide spread use as research tools for gene knockdown. They may also have therapeutic applications.
In molecular biology and genetics, the sense of nucleic acid molecules is the nature of their roles and their complementary molecules' nucleic acid units' roles in specifying amino acids. Depending on the context within molecular biology, sense may have slightly different meanings.
snoRNA U46 is a non-coding RNA (ncRNA) molecule which functions in the modification of other small nuclear RNAs (snRNAs). This type of modifying RNA is usually located in the nucleolus of the eukaryotic cell which is a major site of snRNA biogenesis. It is known as a small nucleolar RNA (snoRNA) and also often referred to as a guide RNA.
SNORD64 is a non-coding RNA (ncRNA) molecule which functions in the biogenesis (modification) of other small nuclear RNAs (snRNAs). This type of modifying RNA is located in the nucleolus of the eukaryotic cell which is a major site of snRNA biogenesis. It is known as a small nucleolar RNA (snoRNA) and also often referred to as a guide RNA.
Natural antisense transcripts (NATs) are a group of RNAs encoded within a cell that have transcript complementarity to other RNA transcripts. They have been identified in multiple eukaryotes, including humans, mice, yeast and Arabidopsis thaliana. This class of RNAs includes both protein-coding and non-coding RNAs. Current evidence has suggested a variety of regulatory roles for NATs, such as RNA interference (RNAi), alternative splicing, genomic imprinting, and X-chromosome inactivation. NATs are broadly grouped into two categories based on whether they act in cis or in trans. Trans-NATs are transcribed from a different location than their targets and usually have complementarity to multiple transcripts with some mismatches. MicroRNAs (miRNA) are an example of trans-NATs that can target multiple transcripts with a few mismatches. Cis-natural antisense transcripts (cis-NATs) on the other hand are transcribed from the same genomic locus as their target but from the opposite DNA strand and form perfect pairs.
Long non-coding RNAs are defined as transcripts longer than 200 nucleotides that are not translated into protein. This somewhat arbitrary limit distinguishes long ncRNAs from small non-coding RNAs such as microRNAs (miRNAs), small interfering RNAs (siRNAs), Piwi-interacting RNAs (piRNAs), small nucleolar RNAs (snoRNAs), and other short RNAs. Long intervening/intergenic noncoding RNAs (lincRNAs) are sequences of lncRNA which do not overlap protein-coding genes.
In molecular biology, complementarity describes a relationship between two structures each following the lock-and-key principle. In nature complementarity is the base principle of DNA replication and transcription as it is a property shared between two DNA or RNA sequences, such that when they are aligned antiparallel to each other, the nucleotide bases at each position in the sequences will be complementary, much like looking in the mirror and seeing the reverse of things. This complementary base pairing allows cells to copy information from one generation to another and even find and repair damage to the information stored in the sequences.
In molecular biology, GNAS antisense RNA , also known as GNAS-AS1, is a long non-coding RNA.It is antisense to the GNAS gene. It is an imprinted gene, expressed only from the paternal allele, suggesting that it may have a role in suppression of the paternal NESP55 allele encoded by GNAS.
In molecular biology, RFPL3 antisense RNA 1, also known as RFPL3-AS1 is a long non-coding RNA. In humans, it is on chromosome 22. It is antisense to the RFPL3 gene encoding a RING finger domain-containing protein. It may function in the post-transcriptional regulation of this gene.
SLC25A25 antisense RNA 1 is a protein that in humans is encoded by the SLC25A25-AS1 gene.
SNAI3 antisense RNA 1 is a protein that in humans is encoded by the SNAI3-AS1 gene.
EGFR antisense RNA 1 is a protein that in humans is encoded by the EGFR-AS1 gene.
FLG antisense RNA 1 is a protein that in humans is encoded by the FLG-AS1 gene.
PTGS2 antisense NFKB1 complex-mediated expression regulator RNA is a protein that in humans is encoded by the PACERR gene.
VIM antisense RNA 1 is a protein that in humans is encoded by the VIM-AS1 gene.
ATP2B1 antisense RNA 1 is a protein that in humans is encoded by the ATP2B1-AS1 gene.
TNRC6C antisense RNA 1 is a protein that in humans is encoded by the TNRC6C-AS1 gene.
