Role of PRKCM (PKC mu) in radiation-induced increase of JUN protooncogene mRNA levels in B-lineage lymphoid cells

Exposure of cells to ionizing radiation results in both activation of prote in kinase C (PRKC, also known as PKC) and induction of transcription of the JUN proto-oncogene, PRKC plays a pivotal role in radiation-induced JUN exp ression, since inhibition of PRKC abrogates the JUN signal. However, the sp ecific PRKC isoforms involved in radiation-induced elevation of JUN mRNA le vels have not been identified. Here we demonstrate that in DT40 B-lineage l ymphoid cells, the mu isoform of PRKC (PRKCM) is critical for the response of JUN to ionizing radiation. The zinc chelator, 1,10-phenanthroline, abrog ated induction of JUN after exposure to ionizing radiation, indicating that this PRKCM-mediated response is also dependent on zinc. (C) 2000 by Radiat ion Research Society.