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CKIalpha is associated with and phosphorylates star-PAP and is also required for expression of select star-PAP target messenger RNAs.
- Source :
-
The Journal of biological chemistry [J Biol Chem] 2008 May 02; Vol. 283 (18), pp. 12665-73. Date of Electronic Publication: 2008 Feb 27. - Publication Year :
- 2008
-
Abstract
- We have recently identified Star-PAP, a nuclear poly(A) polymerase that associates with phosphatidylinositol-4-phosphate 5-kinase Ialpha (PIPKIalpha) and is required for the expression of a specific subset of mRNAs. Star-PAP activity is directly modulated by the PIPKIalpha product phosphatidylinositol 4,5-bisphosphate (PI-4,5-P(2)), linking nuclear phosphoinositide signaling to gene expression. Here, we show that PI-4,5-P(2)-dependent protein kinase activity is also a part of the Star-PAP protein complex. We identify the PI-4,5-P(2)-sensitive casein kinase Ialpha (CKIalpha) as a protein kinase responsible for this activity and further show that CKIalpha is capable of directly phosphorylating Star-PAP. Both CKIalpha and PIPKIalpha are required for the synthesis of some but not all Star-PAP target mRNA, and like Star-PAP, CKIalpha is associated with these messages in vivo. Taken together, these data indicate that CKIalpha, PIPKIalpha, and Star-PAP function together to modulate the production of specific Star-PAP messages. The Star-PAP complex therefore represents a location where multiple signaling pathways converge to regulate the expression of specific mRNAs.
- Subjects :
- Amino Acid Sequence
Animals
Cell Line
Humans
Models, Biological
Molecular Sequence Data
Nucleotidyltransferases
Phosphatidylinositol 4,5-Diphosphate metabolism
Phosphorylation
Phosphotransferases (Alcohol Group Acceptor) metabolism
Polynucleotide Adenylyltransferase chemistry
Proline
Protein Binding
Protein Kinases metabolism
RNA, Messenger genetics
RNA, Messenger metabolism
Rats
Sequence Deletion
Casein Kinase Ialpha metabolism
Gene Expression Regulation
Polynucleotide Adenylyltransferase metabolism
Subjects
Details
- Language :
- English
- ISSN :
- 0021-9258
- Volume :
- 283
- Issue :
- 18
- Database :
- MEDLINE
- Journal :
- The Journal of biological chemistry
- Publication Type :
- Academic Journal
- Accession number :
- 18305108
- Full Text :
- https://doi.org/10.1074/jbc.M800656200