Small nucleolar RNA SNORD115

{{Infobox rfam

| Name = Small nucleolar RNA SNORD115

| image = RF00105.jpg

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| caption = Predicted secondary structure and sequence conservation of SNORD115

| Symbol = SNORD115

| AltSymbols = snoHBII-52; HBII-52

| Rfam = RF00105

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| RNA_type = Gene; snRNA; snoRNA; CD-box

| Tax_domain = Eukaryota

| GO = {{GO|0006396}} {{GO|0005730}}

| SO = {{SO|0000593}}

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In molecular biology, SNORD115 (also known as HBII-52) is a non-coding RNA (ncRNA) molecule known as a small nucleolar RNA which usually functions in guiding the modification of other non-coding RNAs. This type of modifying RNA is usually located in the nucleolus of the eukaryotic cell which is a major site of snRNA biogenesis. HBII-52 refers to the human gene, whereas RBII-52 is used for the rat gene and MBII-52 is used for naming the mouse gene.

HBII-52 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.{{Cite journal | last1 = Galardi | first1 = S.| last2 = Fatica | first2 = A.| last3 = Bachi | first3 = A.| last4 = Scaloni | first4 = A.| last5 = Presutti | first5 = C.| last6 = Bozzoni | first6 = I.| doi = 10.1128/MCB.22.19.6663-6668.2002 | title = Purified Box C/D snoRNPs Are Able to Reproduce Site-Specific 2'-O-Methylation of Target RNA in Vitro | journal = Molecular and Cellular Biology| volume = 22 | issue = 19 | pages = 6663–6668 | date=October 2002 | pmid = 12215523| pmc = 134041}}

In the human genome, HBII-52 is encoded in a tandemly repeated array with another C/D box snoRNA, HBII-85 (SNORD116), in the Prader-Willi syndrome (PWS) region of chromosome 15.{{cite journal | author = Cavaillé J | title = Identification of brain-specific and imprinted small nucleolar RNA genes exhibiting an unusual genomic organization | journal = Proc. Natl. Acad. Sci. U.S.A. | volume = 97 | issue = 26 | pages = 14311–6 | year = 2000 | pmid = 11106375 | doi = 10.1073/pnas.250426397| pmc = 18915 |name-list-style=vanc| author2 = Buiting K | author3 = Kiefmann M | display-authors = 3 | last4 = Lalande | first4 = M | last5 = Brannan | first5 = CI | last6 = Horsthemke | first6 = B | last7 = Bachellerie | first7 = JP | last8 = Brosius | first8 = J | last9 = Hüttenhofer | first9 = A |bibcode = 2000PNAS...9714311C | doi-access = free }} However, a microdeletion in one family of the snoRNA HBII-52 cluster has excluded it from playing a major role in the disease.{{cite journal |vauthors=Runte M, Varon R, Horn D, Horsthemke B, Buiting K |title=Exclusion of the C/D box snoRNA gene cluster HBII-52 from a major role in Prader-Willi syndrome |journal=Hum Genet |volume=116 |issue=3 |pages=228–30 |year=2005 |pmid=15565282 |doi=10.1007/s00439-004-1219-2|s2cid=23190709 }} HBII-52 is found in 47 tandem near identical copies on human chromosome 15q11-13. This locus is maternally imprinted, meaning that only the paternal copy of the locus is transcribed. HBII-52 is exclusively expressed in the brain but is absent in PWS patients. HBII-52 lacks any significant complementarity with ribosomal RNAs, but does have an 18 nucleotide region of conserved complementarity to serotonin 2C receptor mRNA.{{cite journal |vauthors=Kishore S, Stamm S |title=The snoRNA HBII-52 regulates alternative splicing of the serotonin receptor 2C |journal=Science |volume=311 |issue=5758 |pages=230–2 |date=January 2006 |pmid=16357227 |doi=10.1126/science.1118265 |bibcode=2006Sci...311..230K|s2cid=44527461 |doi-access=free }} The serotonin 2C receptor is also expressed in the brain. It has been shown that this snoRNA is likely to bind to a silencing element of exon Vb increasing its inclusion and production of a functional spliceform of the serotonin 2C receptor.

The chromosomal locus containing the SNORD115 gene cluster has been duplicated in many individuals with autistic traits.{{cite journal |author=Bolton PF |title=Chromosome 15q11-13 abnormalities and other medical conditions in individuals with autism spectrum disorders |journal=Psychiatr. Genet. |volume=14 |issue=3 |pages=131–7 |date=September 2004 |pmid=15318025 |doi= 10.1097/00041444-200409000-00002|name-list-style=vanc|author2=Veltman MW |author3=Weisblatt E |display-authors=3 |last4=Holmes |first4=Joanne R. |last5=Thomas |first5=N. Simon |last6=Youings |first6=Sheila A. |last7=Thompson |first7=Russell J. |last8=Roberts |first8=Siân E. |last9=Dennis |first9=Nicholas R.|s2cid=37344935 }}{{cite journal |vauthors=Cook EH, Scherer SW |title=Copy-number variations associated with neuropsychiatric conditions |journal=Nature |volume=455 |issue=7215 |pages=919–23 |date=October 2008 |pmid=18923514 |doi=10.1038/nature07458|bibcode = 2008Natur.455..919C |s2cid=4377899 }} A mouse model engineered to have a duplication of the SNORD115 cluster displays autistic-like behaviour.{{cite journal |author=Nakatani J |title=Abnormal behavior in a chromosome-engineered mouse model for human 15q11-13 duplication seen in autism |journal=Cell |volume=137 |issue=7 |pages=1235–46 |date=June 2009 |pmid=19563756 |doi=10.1016/j.cell.2009.04.024 |name-list-style=vanc|author2=Tamada K |author3=Hatanaka F |display-authors=3 |last4=Ise |first4=Satoko |last5=Ohta |first5=Hisashi |last6=Inoue |first6=Kiyoshi |last7=Tomonaga |first7=Shozo |last8=Watanabe |first8=Yasuhito |last9=Chung |first9=Yeun Jun |pmc=3710970}}

There is evidence that a truncated form of MBII-52 (SNORD115 found in mouse) regulates the alternative splicing of the protein coding genes DPM2, TAF1, RALGPS1, PBRM1, and CRHR1.{{cite journal |vauthors=Kishore S, Khanna A, Zhang Z, Hui J, Balwierz PJ, Stefan M, Beach C, Nicholls RD, Zavolan M, Stamm S |title=The snoRNA MBII-52 (SNORD 115) is processed into smaller RNAs and regulates alternative splicing |journal=Hum Mol Genet |volume= 19|issue= 7|pages= 1153–64|year=2010 |pmid=20053671 |doi=10.1093/hmg/ddp585 |pmc=2838533}}