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Poly(A) polymerase phosphorylation is dependent on novel interactions with cyclins.
- Source :
-
Molecular and cellular biology [Mol Cell Biol] 2000 Jul; Vol. 20 (14), pp. 5310-20. - Publication Year :
- 2000
-
Abstract
- We have previously shown that poly(A) polymerase (PAP) is negatively regulated by cyclin B-cdc2 kinase hyperphosphorylation in the M phase of the cell cycle. Here we show that cyclin B(1) binds PAP directly, and we demonstrate further that this interaction is mediated by a stretch of amino acids in PAP with homology to the cyclin recognition motif (CRM), a sequence previously shown in several cell cycle regulators to target specifically G(1)-phase-type cyclins. We find that PAP interacts with not only G(1)- but also G(2)-type cyclins via the CRM and is a substrate for phosphorylation by both types of cyclin-cdk pairs. PAP's CRM shows novel, concentration-dependent effects when introduced as an 8-mer peptide into binding and kinase assays. While higher concentrations of PAP's CRM block PAP-cyclin binding and phosphorylation, lower concentrations induce dramatic stimulation of both activities. Our data not only support the notion that PAP is directly regulated by cyclin-dependent kinases throughout the cell cycle but also introduce a novel type of CRM that functionally interacts with both G(1)- and G(2)-type cyclins in an unexpected way.
- Subjects :
- Amino Acid Motifs
Animals
CDC2 Protein Kinase genetics
CDC2 Protein Kinase metabolism
Cells, Cultured
Cyclin-Dependent Kinases metabolism
Cyclins genetics
G1 Phase physiology
G2 Phase physiology
Peptide Fragments metabolism
Phosphorylation
Polynucleotide Adenylyltransferase genetics
Cyclins metabolism
Polynucleotide Adenylyltransferase metabolism
Subjects
Details
- Language :
- English
- ISSN :
- 0270-7306
- Volume :
- 20
- Issue :
- 14
- Database :
- MEDLINE
- Journal :
- Molecular and cellular biology
- Publication Type :
- Academic Journal
- Accession number :
- 10866687
- Full Text :
- https://doi.org/10.1128/MCB.20.14.5310-5320.2000