In molecular biology, non-coding RNAs (ncRNA) are RNA molecules that have a function but are not translated into proteins. Small nucleolar RNAs (snoRNAs), one of the largest classes of ncRNA, are further subdivided into the two major C/D and H/ACA snoRNA families. snoRNA serve as guide RNAs for 2'-O-methylation and pseudouridylation of specific nucleotides and indicate the site of modification by direct base pairing with the target RNA. The majority of these snoRNAs are responsible for the post-transcriptional modification of ribosomal RNAs (rRNA) and in some cases of small nuclear RNAs (sRNAs). These post-transcriptional modifications are crucial for rRNA processing, stability and maturation. [1]
The H/ACA snoRNAs that guide pseudouridylation in Trypanosomes consist of a single-hairpin followed by an AGA-box. [1] These H/ACA snoRNA contain a pseudouridylation pocket that guides the H/ACA snoRNA to the correct region of its target rRNA. The pseudouridylation pocket ensures modification of the correct uridine, as it contains two short sequences that are complementary to the target RNA. In addition it is able to basepair with the regions flanking the uridine in need of modification. Trypanosomal snoRNAs differ in both sequence and structure to eukaryotic snoRNAs as they contain one stem loop and an AGA-box at the 3' end. Despite these differences, trypanosomal snoRNAs function identically to eukaryotic snoRNAs and since the discovery of single stem H/ACA snoRNAs in Trypanosomes, similar single hairpin ncRNAs have been discovered in Archea and Euglena. [2] [3] [4] The table below summarizes the H/ACA snoRNAs and the corresponding target sites identified in Trypanosomes. [5]
H/ACA snoRNAs identified in Trypanosomes
H/ACA ID | Target | Reference |
---|---|---|
TB3Cs2H1 | ?308-L5 | Myslyuk et al. 2008 [6] |
TB3Cs2H2 | ?1658-L5 | Myslyuk et al. 2008 [6] |
TB8Cs4H1 | ?358-L3 | Myslyuk et al. 2008 [6] |
TB8Cs4H2 | ?141-L3 | Myslyuk et al. 2008 [6] |
TB9Cs6H1 | ?199-L5, ?29-5.8S | Myslyuk et al. 2008 [6] |
TB9Cs6H2 | ?1653-L5 | Myslyuk et al. 2008 [6] |
TB10Cs5H1 | ?1254-L3 | Myslyuk et al. 2008 [6] |
TB10Cs5H2 | ?131-S | Myslyuk et al. 2008 [6] |
TB10Cs5H3 | ?1276-S | Myslyuk et al. 2008 [6] |
TB11Cs5H1 | ?1710-S | Myslyuk et al. 2008 [6] |
TB11Cs5H2 | ?176-L3 | Myslyuk et al. 2008 [6] |
TB11Cs5H3 | ?1314-L3 | Myslyuk et al. 2008 [6] |
TB6Cs1H1 | ?380-L3 | Liang et al. 2005 [7] |
TB6Cs1H2 | Liang et al. 2005 [7] | |
TB6Cs1H3 | ?662-S | Liang et al. 2005 [7] |
TB6Cs1H4 | ?824-L5 | Liang et al. 2005 [7] |
TB6Cs2H1 | ?1001-SSU | Liang et al. 2005 [7] |
TB8Cs2H1 | ?1113-S | Liang et al. 2005 [7] |
TB8Cs3H1 | ?1423-S | Liang et al. 2005 [7] |
TB9Cs1H1 | ?1088-S,?1272-L3 | Liang et al. 2005 [7] |
TB9Cs1H2 | ?1619-S | Liang et al. 2005 [7] |
TB9Cs1H3 | ?1250-L5 | Liang et al. 2005 [7] |
TB9Cs2H1 | ?617-L3 | Liang et al. 2005 [7] |
TB9Cs2H2 | ?1412-L5 | Liang et al. 2005 [7] |
TB9Cs3H1 | ?1208-L3 | Liang et al. 2005 [7] |
TB9Cs3H2 | ?1103-L5 | Liang et al. 2005 [7] |
TB9Cs4H1 | ?2123-S | Liang et al. 2005 [7] |
TB9Cs4H2 | ?1336-L3 | Liang et al. 2005 [7] |
TB9Cs4H3 | Liang et al. 2005 [7] | |
TB10Cs1H1 | ?659-L3 | Liang et al. 2005 [7] |
TB10Cs1H2 | ?901-L5 | Liang et al. 2005 [7] |
TB10Cs1H3 | ?40-S | Liang et al. 2005 [7] |
TB10Cs2H1 | ?1167-L3 | Liang et al. 2005 [7] |
TB10Cs2H2 | ?1173-L5 | Liang et al. 2005 [7] |
TB10Cs3H1 | ?263-S | Liang et al. 2005 [7] |
TB10Cs3H2 | ?397-L3 | Liang et al. 2005 [7] |
TB10Cs4H1 | ?2248-L5 | Liang et al. 2005 [7] |
TB10Cs4H2 | ?1186-S | Liang et al. 2005 [7] |
TB10Cs4H3 | ?1773-L5 | Liang et al. 2005 [7] |
TB10Cs4H4 | ?505-S | Liang et al. 2005 [7] |
TB11Cs2H1 | ?28 SL | Liang et al. 2005 [7] |
TB11Cs3H1 | ?1308-L3 | Liang et al. 2005 [7] |
TB11Cs3H2 | ?475-L3 | Liang et al. 2005 [7] |
TB11Cs4H1 | ?1357-L3 | Liang et al. 2005 [7] |
TB11Cs4H2 | ?566-L3 | Liang et al. 2005 [7] |
TB11Cs4H3 | ?61-S | Liang et al. 2005 [7] |
TB9Cs3H2 is a member of the H/ACA-like class of non-coding RNA (ncRNA) molecule that guide the sites of modification of uridines to pseudouridines of substrate RNAs. It is known as a small nucleolar RNA (snoRNA) thus named because of its cellular localization in the nucleolus of the eukaryotic cell. TB9Cs3H2 is predicted to guide the pseudouridylation of LSU5 ribosomal RNA (rRNA) at residue Ψ1103.
TB6Cs1H1 is a member of the H/ACA-like class of non-coding RNA (ncRNA) molecule that guide the sites of modification of uridines to pseudouridines of substrate RNAs. It is known as a small nucleolar RNA (snoRNA) thus named because of its cellular localization in the nucleolus of the eukaryotic cell. TB6Cs1H1 is predicted to guide the pseudouridylation of LSU3 ribosomal RNA (rRNA) at residue Ψ380.
TB6Cs1H3 is a member of the H/ACA-like class of non-coding RNA (ncRNA) molecule that guide the sites of modification of uridines to pseudouridines of substrate RNAs. It is known as a small nucleolar RNA (snoRNA) thus named because of its cellular localization in the nucleolus of the eukaryotic cell. TB6Cs1H3 is predicted to guide the pseudouridylation of SSU ribosomal RNA (rRNA) at residue Ψ662.
TB10Cs1H1 is a member of the H/ACA-like class of non-coding RNA (ncRNA) molecule that guide the sites of modification of uridines to pseudouridines of substrate RNAs. It is known as a small nucleolar RNA (snoRNA) thus named because of its cellular localization in the nucleolus of the eukaryotic cell. TB10Cs1H1 is predicted to guide the pseudouridylation of LSU3 ribosomal RNA (rRNA) at residue Ψ659.
TB9Cs2H1 is a member of the H/ACA-like class of non-coding RNA (ncRNA) molecule that guide the sites of modification of uridines to pseudouridines of substrate RNAs. It is known as a small nucleolar RNA (snoRNA) thus named because of its cellular localization in the nucleolus of the eukaryotic cell. TB9Cs2H1 is predicted to guide the pseudouridylation of LSU3 ribosomal RNA (rRNA) at residue Ψ617.
TB10Cs2H1 is a member of the H/ACA-like class of non-coding RNA (ncRNA) molecule that guide the sites of modification of uridines to pseudouridines of substrate RNAs. It is known as a small nucleolar RNA (snoRNA) thus named because of its cellular localization in the nucleolus of the eukaryotic cell. TB10Cs2H1 is predicted to guide the pseudouridylation of LSU3 ribosomal RNA (rRNA) at residue Ψ1167.
TB10Cs3H2 is a member of the H/ACA-like class of non-coding RNA (ncRNA) molecule that guide the sites of modification of uridines to pseudouridines of substrate RNAs. It is known as a small nucleolar RNA (snoRNA) thus named because of its cellular localization in the nucleolus of the eukaryotic cell. TB10Cs3H2 is predicted to guide the pseudouridylation of LSU3 ribosomal RNA (rRNA) at residue Ψ397.
TB8Cs2H1 is a member of the H/ACA-like class of non-coding RNA (ncRNA) molecule that guide the sites of modification of uridines to pseudouridines of substrate RNAs. It is known as a small nucleolar RNA (snoRNA) thus named because of its cellular localization in the nucleolus of the eukaryotic cell. TB8Cs2H1 is predicted to guide the pseudouridylation of SSU ribosomal RNA (rRNA) at residue Ψ1113.
TB10Cs4H4 is a member of the H/ACA-like class of non-coding RNA (ncRNA) molecule that guide the sites of modification of uridines to pseudouridines of substrate RNAs. It is known as a small nucleolar RNA (snoRNA) thus named because of its cellular localization in the nucleolus of the eukaryotic cell. TB10Cs4H4 is predicted to guide the pseudouridylation of SSU ribosomal RNA (rRNA) at residue Ψ505.
TB11Cs4H3 is a member of the H/ACA-like class of non-coding RNA (ncRNA) molecule that guide the sites of modification of uridines to pseudouridines of substrate RNAs. It is known as a small nucleolar RNA (snoRNA) thus named because of its cellular localization in the nucleolus of the eukaryotic cell. TB11Cs4H3 is predicted to guide the pseudouridylation of LSU3 ribosomal RNA (rRNA) at residue Ψ566.
TB6Cs1H4 is a member of the H/ACA-like class of non-coding RNA (ncRNA) molecule that guide the sites of modification of uridines to pseudouridines of substrate RNAs. It is known as a small nucleolar RNA (snoRNA) thus named because of its cellular localization in the nucleolus of the eukaryotic cell. TB6Cs1H4 is predicted to guide the pseudouridylation of LSU5 ribosomal RNA (rRNA) at residue Ψ824.
TB9Cs1H2 is a member of the H/ACA-like class of non-coding RNA (ncRNA) molecule that guide the sites of modification of uridines to pseudouridines of substrate RNAs. It is known as a small nucleolar RNA (snoRNA) thus named because of its cellular localization in the nucleolus of the eukaryotic cell. TB9Cs1H2 is predicted to guide the pseudouridylation of SSU ribosomal RNA (rRNA) at residue Ψ1619.
TB8Cs4H2 is a member of the H/ACA-like class of non-coding RNA (ncRNA) molecule that guide the sites of modification of uridines to pseudouridines of substrate RNAs. It is known as a small nucleolar RNA (snoRNA) thus named because of its cellular localization in the nucleolus of the eukaryotic cell. TB8Cs4H2 is predicted to guide the pseudouridylation of LSU3 ribosomal RNA (rRNA) at residue Ψ141.
TB10Cs4H2 is a member of the H/ACA-like class of non-coding RNA (ncRNA) molecule that guide the sites of modification of uridines to pseudouridines of substrate RNAs. It is known as a small nucleolar RNA (snoRNA) thus named because of its cellular localization in the nucleolus of the eukaryotic cell. TB10Cs4H2 is predicted to guide the pseudouridylation of SSU ribosomal RNA (rRNA) at residue Ψ1186.
TB10Cs5H3 is a member of the H/ACA-like class of non-coding RNA (ncRNA) molecule that guide the sites of modification of uridines to pseudouridines of substrate RNAs. It is known as a small nucleolar RNA (snoRNA) thus named because of its cellular localization in the nucleolus of the eukaryotic cell. TB10Cs5H3 is predicted to guide the pseudouridylation of SSU ribosomal RNA (rRNA) at residue Ψ1276.
TB10Cs5H2 is a member of the H/ACA-like class of non-coding RNA (ncRNA) molecule that guide the sites of modification of uridines to pseudouridines of substrate RNAs. It is known as a small nucleolar RNA (snoRNA) thus named because of its cellular localization in the nucleolus of the eukaryotic cell. TB10Cs5H2 is predicted to guide the pseudouridylation of SSU ribosomal RNA (rRNA) at residue Ψ131.
TB6Cs2H1 is a member of the H/ACA-like class of non-coding RNA (ncRNA) molecule that guide the sites of modification of uridines to pseudouridines of substrate RNAs. It is known as a small nucleolar RNA (snoRNA) thus named because of its cellular localization in the nucleolus of the eukaryotic cell. TB6Cs2H1 is predicted to guide the pseudouridylation of SSU ribosomal RNA (rRNA) at residue Ψ1101.
TB9Cs1H3 is a member of the H/ACA-like class of non-coding RNA (ncRNA) molecule that guide the sites of modification of uridines to pseudouridines of substrate RNAs. It is known as a small nucleolar RNA (snoRNA) thus named because of its cellular localization in the nucleolus of the eukaryotic cell. TB9Cs1H3 is predicted to guide the pseudouridylation of LSU5 ribosomal RNA (rRNA) at residue Ψ1250.
TB11Cs3H1 is a member of the H/ACA-like class of non-coding RNA (ncRNA) molecule that guide the sites of modification of uridines to pseudouridines of substrate RNAs. It is known as a small nucleolar RNA (snoRNA) thus named because of its cellular localization in the nucleolus of the eukaryotic cell. TB11Cs3H1 is predicted to guide the pseudouridylation of LSU3 ribosomal RNA (rRNA) at residue Ψ1308.
TB10Cs5H1 is a member of the H/ACA-like class of non-coding RNA (ncRNA) molecule that guide the sites of modification of uridines to pseudouridines of substrate RNAs. It is known as a small nucleolar RNA (snoRNA) thus named because of its cellular localization in the nucleolus of the eukaryotic cell. TB10Cs5H1 is predicted to guide the pseudouridylation of LSU3 ribosomal RNA (rRNA) at residue Ψ1254.