Table 2.
Emerging classes of non-coding RNAs
| Short name |
Full name | Source | Processing enzyme | Function | Referencew | |
|---|---|---|---|---|---|---|
| sdRNA | sno- derived RNAs | snoRNAs | unknown, | see Figure 2 | [6,32,34] | |
| PARs | Promoter-associated RNA |
transcription regulation |
[78] | |||
| a | tiRNA | transcription initiation RNAs |
RNA pol II transcription, backtracking on coding and non- coding genes |
TFIIs transcription factor endonucleolitic cleavage |
transcription regulation |
[6] |
| b | PASR | Promoter-associated small RNAs |
Processing of mature mRNAs? | unknown | transcription regulation |
[79] |
| c | TSSa-RNAs | transcription start site associated RNAs |
unknown | unknown | transcription regulation |
[80] |
| tRFs | tRNA fragments | tRNA | Dicer, RNase Z or unknown |
Endogenous targets have not demonstrated; |
[81] | |
| moRs | miRNA-offset RNAs | pre-miRNA | Unknown exonuclease and Drosha? |
unknown | [82] | |
| spliRNA | Splice-site RNAs | cleavage of nascent transcript? | unknown | 3’-termini maps to pre-mRNA splice donor site |
[83] | |
| crasiRNA | Centromere- associated RNAs |
transcription of centromeric repeats from retroviral promoters |
processed from dsRNA by unknown pathway |
Heterochromatin formation and centromer identity |
[84] | |
| tel-sRNA | Telomere small RNAs | long telomere RNA transcript? | Dicer independent | epigenetic regulation | [85] | |
| TASR | gene-termini- associated human RNAs |
uncharacterized pathway of copying 3’-genes terminies |
unknown | unknown | [86][87] | |
| -.- | Processed long- noncoding RNAs |
unknown | unknown | unknown | [88] | |