Protein: Speckle targeted PIP5K1A-regulated poly(A) polymerase (Star-PAP) (EC 2.7.7.19) (RNA-binding motif protein 21) (RNA-binding protein 21) (U6 snRNA-specific terminal uridylyltransferase 1) (U6-TUTase) (EC 2.7.7.52) (Q9H6E5)
Organism: Homo sapiens (Human)
Function: Poly(A) polymerase that creates the 3'-poly(A) tail of specific pre-mRNAs. Localizes to nuclear speckles together with PIP5K1A and mediates polyadenylation of a select set of mRNAs, such as HMOX1. In addition to polyadenylation, it is also required for the 3'-end cleavage of pre-mRNAs: binds to the 3'UTR of targeted pre-mRNAs and promotes the recruitment and assembly of the CPSF complex on the 3'UTR of pre-mRNAs. In addition to adenylyltransferase activity, also has uridylyltransferase activity. However, the ATP ratio is higher than UTP in cells, suggesting that it functions primarily as a poly(A) polymerase. Acts as a specific terminal uridylyltransferase for U6 snRNA in vitro: responsible for a controlled elongation reaction that results in the restoration of the four 3'-terminal UMP-residues found in newly transcribed U6 snRNA. Not involved in replication-dependent histone mRNA degradation.
Subcellular location: Nucleus, nucleolus {ECO:0000269|PubMed:16790842}. Nucleus speckle {ECO:0000269|PubMed:18288197, ECO:0000269|PubMed:18305108}.
Sequence: MAAVDSDVESLPRGGFRCCLCHVTTANRPSLDAHLGGRKHRHLVELRAARKAQGLRSVFVSGFPRDVDSAQLSEYFLAFGPVASVVMDKDKGVFAIVEMGDVGAREAVLSQSQHSLGGHRLRVRPREQKEFQSPASKSPKGAAPDSHQLAKALAEAADVGAQMIKLVGLRELSEAERQLRSLVVALMQEVFTEFFPGCVVHPFGSSINSFDVHGCDLDLFLDLGDLEEPQPVPKAPESPSLDSALASPLDPQALACTPASPPDSQPPASPQDSEALDFETPSSSLAPQTPDSALASETLASPQSLPPASPLLEDREEGDLGKASELAETPKEEKAEGAAMLELVGSILRGCVPGVYRVQTVPSARRPVVKFCHRPSGLHGDVSLSNRLALHNSRFLSLCSELDGRVRPLVYTLRCWAQGRGLSGSGPLLSNYALTLLVIYFLQTRDPPVLPTVSQLTQKAGEGEQVEVDGWDCSFPRDASRLEPSINVEPLSSLLAQFFSCVSCWDLRGSLLSLREGQALPVAGGLPSNLWEGLRLGPLNLQDPFDLSHNVAANVTSRVAGRLQNCCRAAANYCRSLQYQRRSSRGRDWGLLPLLQPSSPSSLLSATPIPLPLAPFTQLTAALVQVFREALGCHIEQATKRTRSEGGGTGESSQGGTSKRLKVDGQKNCCEEGKEEQQGCAGDGGEDRVEEMVIEVGEMVQDWAMQSPGQPGDLPLTTGKHGAPGEEGQPSHAALAERGPKGHEAAQEWSQGEAGKGASLPSSASWRCALWHRVWQGRRRARRRLQQQTKEGAGGGAGTRAGWLATEAQVTQELKGLSGGEERPETEPLLSFVASVSPADRMLTVTPLQDPQGLFPDLHHFLQVFLPQAIRHLK
InterPro domains: - IPR002058: PAP/25A-associated (domain) [491-549]
- IPR035979: RNA-binding domain superfamily (homologous_superfamily) [54-132]
- IPR012677: Nucleotide-binding alpha-beta plait domain superfamily (homologous_superfamily) [54-126]
- IPR036236: Zinc finger C2H2 superfamily (homologous_superfamily) [5-46]
- IPR043519: Nucleotidyltransferase superfamily (homologous_superfamily) [158-401]
- IPR013087: Zinc finger C2H2-type (domain) [16-40]
- IPR034388: Star-PAP, RNA recognition motif (domain) [54-127]
- IPR054708: Poly(A) RNA polymerase, mitochondrial-like, central palm domain (domain) [162-398]
- IPR000504: RNA recognition motif domain (domain) [56-128]
Interaction partners: - Poly
- Poly
- Poly
- Spliceosome associated factor 3, U4/U6 recycling protein
- Protein lin-28 homolog A
- U4/U6 small nuclear ribonucleoprotein Prp4
- U4/U6 small nuclear ribonucleoprotein Prp31
- Phosphatidylinositol 5-phosphate 4-kinase type-2 alpha
- DIS3-like exonuclease 2
- Centrosomal AT-AC splicing factor
Gene Ontology annotations:
Molecular Function (MF): GO:0003674 (molecular function), GO:0005488 (binding), GO:0003824 (catalytic activity), GO:0140640 (catalytic activity, acting on a nucleic acid), GO:0097159 (organic cyclic compound binding), GO:1901363 (heterocyclic compound binding), GO:0016740 (transferase activity), GO:0005515 (protein binding), GO:0003676 (nucleic acid binding), GO:0140098 (catalytic activity, acting on RNA), GO:0016772 (transferase activity, transferring phosphorus-containing groups), GO:0003723 (RNA binding), GO:0016779 (nucleotidyltransferase activity), GO:0070569 (uridylyltransferase activity)
Biological Process (BP): GO:0008150 (biological process), GO:0008152 (metabolic process), GO:0065007 (biological regulation), GO:0050789 (regulation of biological process), GO:0009987 (cellular process), GO:0048519 (negative regulation of biological process), GO:0044237 (cellular metabolic process), GO:0019222 (regulation of metabolic process), GO:0006807 (nitrogen compound metabolic process), GO:0071704 (organic substance metabolic process), GO:0009056 (catabolic process), GO:0044238 (primary metabolic process), GO:0009892 (negative regulation of metabolic process), GO:1901360 (organic cyclic compound metabolic process), GO:0006139 (nucleobase-containing compound metabolic process), GO:0046483 (heterocycle metabolic process), GO:0010605 (negative regulation of macromolecule metabolic process), GO:0044248 (cellular catabolic process), GO:0060255 (regulation of macromolecule metabolic process), GO:0006725 (cellular aromatic compound metabolic process), GO:0034641 (cellular nitrogen compound metabolic process), GO:1901575 (organic substance catabolic process), GO:0044260 (cellular macromolecule metabolic process), GO:0043170 (macromolecule metabolic process), GO:0034655 (nucleobase-containing compound catabolic process), GO:0009057 (macromolecule catabolic process), GO:0044270 (cellular nitrogen compound catabolic process), GO:0090304 (nucleic acid metabolic process), GO:0044265 (cellular macromolecule catabolic process), GO:0019439 (aromatic compound catabolic process), GO:1901361 (organic cyclic compound catabolic process), GO:0046700 (heterocycle catabolic process), GO:0010467 (gene expression), GO:0010629 (negative regulation of gene expression), GO:0010468 (regulation of gene expression), GO:0016070 (RNA metabolic process), GO:0006402 (mRNA catabolic process), GO:0006401 (RNA catabolic process), GO:0006396 (RNA processing), GO:0034470 (ncRNA processing), GO:0034661 (ncRNA catabolic process), GO:0034660 (ncRNA metabolic process), GO:0035196 (miRNA processing), GO:0010586 (miRNA metabolic process)
Cellular Component (CC): GO:0005575 (cellular component), GO:0110165 (cellular anatomical entity), GO:0005622 (intracellular anatomical structure), GO:0043226 (organelle), GO:0005829 (cytosol), GO:0005737 (cytoplasm), GO:0031974 (membrane-enclosed lumen), GO:0005654 (nucleoplasm), GO:0043233 (organelle lumen), GO:0043229 (intracellular organelle), GO:0043227 (membrane-bounded organelle), GO:0043228 (non-membrane-bounded organelle), GO:0043231 (intracellular membrane-bounded organelle), GO:0070013 (intracellular organelle lumen), GO:0043232 (intracellular non-membrane-bounded organelle), GO:0031981 (nuclear lumen), GO:0005730 (nucleolus), GO:0005634 (nucleus)