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Substrate Specificity of the Kinase P-TEFb towards the RNA Polymerase II C-Terminal Domain.

ABSTRACT: The positive transcription elongation factor b (P-TEFb) promotes transcription elongation through phosphorylation of the RNA polymerase II C-terminal domain. This process is not well understood, partly due to difficulties in determining the specificity of P-TEFb toward the various heptad repeat motifs within the C-terminal domain. A simple assay using mass spectrometry was developed to identify the substrate specificity of the Drosophila melanogaster P-TEFb (DmP-TEFb) in vitro. This assay demonstrated that DmP-TEFb preferentially phosphorylates Ser5 and, surprisingly, that pre-phosphorylation or conserved amino acid variation at the 7-position in the heptad can alter DmP-TEFb specificity, leading to the creation of distinct double-phosphorylation marks.

SUBMITTER: Gibbs EB

PROVIDER: S-EPMC5685781 | biostudies-literature | 2017 Nov

REPOSITORIES: biostudies-literature

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Substrate Specificity of the Kinase P-TEFb towards the RNA Polymerase II C-Terminal Domain.

Gibbs Eric B EB Laremore Tatiana N TN Usher Grace A GA Portz Bede B Cook Erik C EC Showalter Scott A SA

Biophysical journal 20171006 9

The positive transcription elongation factor b (P-TEFb) promotes transcription elongation through phosphorylation of the RNA polymerase II C-terminal domain. This process is not well understood, partly due to difficulties in determining the specificity of P-TEFb toward the various heptad repeat motifs within the C-terminal domain. A simple assay using mass spectrometry was developed to identify the substrate specificity of the Drosophila melanogaster P-TEFb (DmP-TEFb) in vitro. This assay demons ...[more]

PMID: 28992937

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