CKIα Is Associated with and Phosphorylates Star-PAP and Is Also Required for Expression of Select Star-PAP Target Messenger RNAs*
| Autor: | Richard A. Anderson, Michael L. Gonzales, David L. Mellman |
|---|---|
| Jazyk: | angličtina |
| Rok vydání: | 2008 |
| Předmět: |
Phosphatidylinositol 4
5-Diphosphate endocrine system Proline Molecular Sequence Data Biochemistry Models Biological Cell Line chemistry.chemical_compound Gene expression Animals Humans Phosphatidylinositol Amino Acid Sequence RNA Messenger Phosphorylation Protein kinase A Molecular Biology Polymerase Sequence Deletion biology Kinase Casein Kinase Ialpha Polynucleotide Adenylyltransferase Cell Biology Nucleotidyltransferases female genital diseases and pregnancy complications Rats RNA: Processing and Catalysis Phosphotransferases (Alcohol Group Acceptor) chemistry Gene Expression Regulation biology.protein Casein kinase 1 Signal transduction Protein Kinases Protein Binding |
| Popis: | 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. |
| Databáze: | OpenAIRE |
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