LIS - Legume Information System
Information about legume traits for crop improvement
CicerMine
v5.1.0.3
Cicer data from the Legume Information System
v5.1.0.3
Cicer data from the Legume Information System
| Type | Domain |
| Description | This entry represents the RNA recognition motif (RRM) of Star-PAP (Speckle targeted PIPKIalpha regulated poly (A) polymerase), which is a nuclear non-canonical PAP (Poly(A) polymerase) regulated by lipid second messenger phosphatidyl-inositol-4,5-bisphosphate (PI4,5P2) [ ]. As its name suggests, Star-PAP interacts and is regulated by the enzyme phosphatidyl-inositol-4-phosphate-5-kinase type I alpha (PIPKIalpha) that synthesises nuclear PI4,5P2. Star-PAP polyadenylates select subset of mRNAs in the cell involved in oxidative stress response, apoptosis and cancer[ , , ]. Although it belongs to the well-characterised poly(A) polymerase protein superfamily, Star-PAP is highly divergent from both the poly(A) polymerase (PAP) and the terminal uridylyl transferase (TUTase), identified within the editing complexes of trypanosomes. Star-PAP contains an N-terminal C2H2-type zinc finger motif followed by an RNA recognition motif (RRM), a split PAP domain linked by a proline-rich region, a PAP catalytic and core domain, a PAP-associated domain, an RS repeat, and a nuclear localization signal (NLS).Almost all eukaryotic mRNAs acquire a poly(A) tail at the 3'-end which confers stability and is required for export and translation of the mRNA. Polyadenylation is carried out by a 3'-end processing complex in a two-step reaction: cleavage at the 3'-UTR followed by the addition of poly (A) tail to the cleaved RNA. The canonical PAP, PAPalpha, is the major nuclear PAP is responsible for the general polyadenylation of nuclear pre-mRNAs. However, several non-canonical PAPs have been identified, such as Star-PAP [ ]. Interestingly, the mechanism for pre-mRNA cleavage and polyadenylation is different for PAPalpha and Star-PAP. PAPalpha is recruited to UTR RNA by the interaction with CPSF and CstF, while Star-PAP directly binds the target UTR RNA upstream of poly (A) signal (PAS) and recruits the cleavage factor CPSF-160 and CPSF-73 []. |
| Short Name | Star-PAP_RRM |
