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Phosphorylation-dependent interaction between the splicing factors SAP155 and NIPP1.
- Source :
-
The Journal of biological chemistry [J Biol Chem] 2002 Aug 30; Vol. 277 (35), pp. 31834-41. Date of Electronic Publication: 2002 Jun 24. - Publication Year :
- 2002
-
Abstract
- NIPP1 is a ubiquitously expressed nuclear protein that functions both as a regulator of protein Ser/Thr phosphatase-1 and as a splicing factor. The N-terminal part of NIPP1 consists of a phosphothreonine-interacting Forkhead-associated (FHA) domain. We show here that the FHA domain of NIPP1 interacts in vitro and in vivo with a TP dipeptide-rich fragment of the splicing factor SAP155/SF3b(155), a component of the U2 small nuclear ribonucleoprotein particle. The NIPP1-SAP155 interaction was entirely dependent on the phosphorylation of specific TP motifs in SAP155. Mutagenesis and competition studies revealed that various phosphorylated TP motifs competed for binding to the same site in the FHA domain. The SAP155 kinases in cell lysates were blocked by the Ca(2+) chelator EGTA and by the cyclin-dependent protein kinase inhibitor roscovitine. The phosphorylation level of SAP155 was dramatically increased during mitosis, and accordingly the activity of SAP155 kinases was augmented in mitotic lysates. We discuss how the interaction between NIPP1 and SAP155 could contribute to spliceosome (dis)assembly and the catalytic steps of splicing.
- Subjects :
- Adaptor Proteins, Signal Transducing
Amino Acid Sequence
Animals
Cloning, Molecular
Cyclin-Dependent Kinase 2
Cyclin-Dependent Kinases metabolism
Female
Glutathione Transferase genetics
Glutathione Transferase metabolism
Liver metabolism
Molecular Sequence Data
Oocytes physiology
Peptide Fragments chemistry
Phosphoprotein Phosphatases
Phosphorylation
Protein Phosphatase 1
Protein Serine-Threonine Kinases metabolism
Recombinant Fusion Proteins metabolism
Saccharomyces cerevisiae genetics
Spliceosomes metabolism
Xenopus Proteins
Xenopus laevis
CDC2-CDC28 Kinases
Carrier Proteins
Endoribonucleases
Intracellular Signaling Peptides and Proteins
Peptide Fragments metabolism
Phosphoproteins metabolism
RNA-Binding Proteins metabolism
Ribonucleoprotein, U2 Small Nuclear metabolism
Saccharomyces cerevisiae Proteins
Subjects
Details
- Language :
- English
- ISSN :
- 0021-9258
- Volume :
- 277
- Issue :
- 35
- Database :
- MEDLINE
- Journal :
- The Journal of biological chemistry
- Publication Type :
- Academic Journal
- Accession number :
- 12105215
- Full Text :
- https://doi.org/10.1074/jbc.M204427200