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  • The EMBO Journal (2003) 22, 925 - 934
  • doi:10.1093/emboj/cdg077

The C-terminal domain of pol II and a DRB-sensitive kinase are required for 3' processing of U2 snRNA

Joanne E. Medlin1, Patricia Uguen1, Alice Taylor1, David L. Bentley2 and Shona Murphy1

  1. Sir William Dunn School of Pathology, University of Oxford, South Parks Road, Oxford OX1 3RE, UK
  2. Department of Biochemistry and Molecular Genetics, University of Colorado Health Sciences Center, B121, 4200 East 9th Avenue, Denver, CO 80262, USA

Correspondence to:

Shona Murphy, E-mail: shona.murphy@pathology.ox.ac.uk

Received 9 July 2002; Accepted 16 December 2002; Revised 11 November 2002

The human snRNA genes transcribed by RNA polymerase II (e.g. U1 and U2) have a characteristic TATA-less promoter containing an essential proximal sequence element. Formation of the 3' end of these non-polyadenylated RNAs requires a specialized 3' box element whose function is promoter specific. Here we show that truncation of the C-terminal domain (CTD) of RNA polymerase II and treatment of cells with CTD kinase inhibitors, including DRB (5,6-dichloro-1-beta-D-ribofuranosylbenzimidazole), causes a dramatic reduction in proper 3' end formation of U2 transcripts. Activation of 3' box recognition by the phosphorylated CTD would be consistent with the role of phospho-CTD in mRNA processing. CTD kinase inhibitors, however, have little effect on initiation or elongation of transcription of the U2 genes, whereas elongation of transcription of the beta-actin gene is severely affected. This result highlights differences in transcription of snRNA and mRNA genes.

  • Keywords:

    • CTD,
    • pol II,
    • RNA processing,
    • snRNA,
    • transcription