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PubMed · 10625661

Phosphorylation modulates the function of the vasoactive intestinal polypeptide receptor transcriptional repressor protein.

L Pei
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Abstract

The transcriptional repressor for rat vasoactive intestinal polypeptide receptor 1 (VIPR-RP) is a recently isolated transcription factor. In this study, we have characterized the functional domains of VIPR-RP and the importance of phosphorylation on VIPR-RP function. Using various regions of VIPR-RP in gel mobility shift assays, we show that the amino acid sequences between positions 367 and 475 play an essential role for VIPR-RP DNA binding. Transient transfection of fusion constructs containing GAL4 DNA binding domain and different parts of VIPR-RP indicated that there are two separate transcriptional repression domains in VIPR-RP, located between amino acids 50 and 101 and between 469 and 527. We demonstrated that VIPR-RP is phosphorylated in vitro by casein kinase II on Ser-69/71 and Thr-110, and by cAMP-dependent kinase on Ser-245/361. Furthermore, by site-directed mutagenesis, we show that phosphorylation of the casein kinase II sites potentiates VIPR-RP transcriptional repression activity by enhancing its nuclear translocation, and that phosphorylation by cAMP-dependent kinase inhibits VIPR- RP transcriptional repression function without affecting its subcellular localization. These observations suggest that phosphorylation plays an important role in regulating VIPR-RP function.

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Amino Acid SequenceAnimalsCOS CellsCasein Kinase IICell LineConsensus SequenceCyclic AMP-Dependent Protein KinasesMutagenesis, Site-DirectedPhosphorylationProtein BiosynthesisProtein Serine-Threonine KinasesRatsRecombinant Fusion ProteinsRecombinant ProteinsReplication Protein CRepressor ProteinsSerineThreonineTranscription FactorsTranscription, GeneticTransfectionJournal ArticleResearch Support, Non-U.S. Gov'tResearch Support, U.S. Gov't, P.H.S.

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L Pei. 2000-01-14. Phosphorylation modulates the function of the vasoactive intestinal polypeptide receptor transcriptional repressor protein.. https://doi.org/10.1074/jbc.275.2.1176

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