Small nucleolar RNA SNORD116
Encyclopedia
SNORD116 is a non-coding RNA
(ncRNA) molecule which functions in the modification of other small nuclear RNA
s (snRNAs). This type of modifiying 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.
SNORD116 belongs to the C/D box class of snoRNAs which contain the conserved sequence motifs known as the C box (UGAUGA) and the D box (CUGA). Most of the members of the box C/D family function in directing site-specific 2'-O-methylation
of substrate RNAs.
In the human genome, there are 29 tandemnly repeated copies of SNORD116, followed by 48 copies of another C/D box snoRNA, SNORD115
, in the Prader-Willi syndrome
(PWS) region of chromosome 15. Unlike most other snoRNAs, SNORD116 is expressed prevalently in the brain (but is absent in PWS patients) and lacks any significant complementarity with ribosomal RNA. Mouse models of PWS show similar symptoms to humans (hyperphagia and growth deficiency), providing further evidence that PWS is directly linked to the deletion of SNORD116.
More evidence comes from the discovery of two individuals that share many traits of PWS sufferers, both have atypical microdeletions on chromosome 15q11-13, the intersection of which contains only the SNORD116 snoRNAs. An early paper, however, disputes these findings.
The targets of SNORD116 are unknown, however a bioinformatic screen located 23 possible targets within protein coding genes, of these a large fraction were found to be alternatively spliced, suggesting a role of SNORD116 in the regulation of alternative splicing.
Non-coding RNA
A non-coding RNA is a functional RNA molecule that is not translated into a protein. Less-frequently used synonyms are non-protein-coding RNA , non-messenger RNA and functional RNA . The term small RNA is often used for short bacterial ncRNAs...
(ncRNA) molecule which functions in the modification of other small nuclear RNA
Small nuclear RNA
Small nuclear ribonucleic acid is a class of small RNA molecules that are found within the nucleus of eukaryotic cells. They are transcribed by RNA polymerase II or RNA polymerase III and are involved in a variety of important processes such as RNA splicing , regulation of transcription factors ...
s (snRNAs). This type of modifiying RNA is usually located in the nucleolus
Nucleolus
The nucleolus is a non-membrane bound structure composed of proteins and nucleic acids found within the nucleus. Ribosomal RNA is transcribed and assembled within the nucleolus...
of the eukaryotic cell which is a major site of snRNA biogenesis. It is known as a small nucleolar RNA
SnoRNA
Small nucleolar RNAs are a class of small RNA molecules that primarily guide chemical modifications of other RNAs, mainly ribosomal RNAs, transfer RNAs and small nuclear RNAs...
(snoRNA) and also often referred to as a guide RNA.
SNORD116 belongs to the C/D box class of snoRNAs which contain the conserved sequence motifs known as the C box (UGAUGA) and the D box (CUGA). Most of the members of the box C/D family function in directing site-specific 2'-O-methylation
Methylation
In the chemical sciences, methylation denotes the addition of a methyl group to a substrate or the substitution of an atom or group by a methyl group. Methylation is a form of alkylation with, to be specific, a methyl group, rather than a larger carbon chain, replacing a hydrogen atom...
of substrate RNAs.
In the human genome, there are 29 tandemnly repeated copies of SNORD116, followed by 48 copies of another C/D box snoRNA, SNORD115
Small nucleolar RNA SNORD115
SNORD115 is a non-coding RNA molecule known as a small nucleoloar RNA which usually functions in guiding the modification of other non-coding RNAs. This type of modifiying RNA is usually located in the nucleolus of the eukaryotic cell which is a major site of snRNA biogenesis...
, in the Prader-Willi syndrome
Prader-Willi syndrome
Prader–Willi syndrome is a rare genetic disorder in which seven genes on chromosome 15 are deleted or unexpressed on the paternal chromosome...
(PWS) region of chromosome 15. Unlike most other snoRNAs, SNORD116 is expressed prevalently in the brain (but is absent in PWS patients) and lacks any significant complementarity with ribosomal RNA. Mouse models of PWS show similar symptoms to humans (hyperphagia and growth deficiency), providing further evidence that PWS is directly linked to the deletion of SNORD116.
More evidence comes from the discovery of two individuals that share many traits of PWS sufferers, both have atypical microdeletions on chromosome 15q11-13, the intersection of which contains only the SNORD116 snoRNAs. An early paper, however, disputes these findings.
The targets of SNORD116 are unknown, however a bioinformatic screen located 23 possible targets within protein coding genes, of these a large fraction were found to be alternatively spliced, suggesting a role of SNORD116 in the regulation of alternative splicing.