Apoptosis

, Volume 14, Issue 10, pp 1154–1164

TPCK-induced apoptosis and labelling of the largest subunit of RNA polymerase II in Jurkat cells

Authors

  • Z. Fabian
    • Pharmacology and TherapeuticsSchool of Medicine and National Centre for Biomedical Engineering Science, School of Science, Room 213, Orbsen Building
    • Department of Medical BiologyUniversity of Pécs
  • P. O’Brien
    • Pharmacology and TherapeuticsSchool of Medicine and National Centre for Biomedical Engineering Science, School of Science, Room 213, Orbsen Building
  • K. Pajęcka
    • Science Foundation Ireland Undergraduate Research Experience and Knowledge Award Programme
    • Pharmacology and TherapeuticsSchool of Medicine and National Centre for Biomedical Engineering Science, School of Science, Room 213, Orbsen Building
Original Paper

DOI: 10.1007/s10495-009-0386-y

Cite this article as:
Fabian, Z., O’Brien, P., Pajęcka, K. et al. Apoptosis (2009) 14: 1154. doi:10.1007/s10495-009-0386-y

Abstract

N-α-Tosyl-l-phenylalanyl chloromethyl ketone (TPCK) is an affinity label for chymotrypsin-like proteases and has been extensively used as an experimental tool in apoptosis research to probe the role of proteases in cell death. While TPCK blocks some apoptotic changes and induces others, the cellular target or targets for TPCK have not been identified. Here we investigated for the first time the cellular targets for TPCK using a polyclonal anti-tosyl antibody. We have found that TPCK rapidly and irreversibly labels numerous intracellular proteins and have identified one as RPB1, the largest subunit of RNA polymerase II. We show that TPCK inhibits DNA binding by RNA polymerase and that TPCK inhibits transcription. Inhibition of transcription is known to induce apoptosis and while TPCK may trigger death through interaction with multiple targets, our data suggests that the pro-apoptotic effects of TPCK may be explained in part by the inhibition of RNA polymerase II activity.

Keywords

TPCKAnti-tosyl antibodyDFF40DFF35/45RNA polymerase IIRPB1

Copyright information

© Springer Science+Business Media, LLC 2009