An atm/chk2 signaling pathway induces nuclear translocation of srpk2 in cisplatin-treated hela cells

Abstract

Chemotherapeutic agents are frequently used to treat various cancers, but the mechanisms mediating the cellular response to the drugs are still not fully understood. We previously reported that the nuclear translocation of serine/arginine protein kinases (SRPKs), triggered by the exposure of cells to DNA damage-inducers, plays a pivotal role in drug responsiveness. Here, we investigated the mechanism linking the nuclear accumulation of SRPK2 to the cisplatin treatment of HeLa cells. We present experimental evidence that nuclear SRPK2 acts downstream of Chk2 in the ATM/Chk2 cascade. The inhibition of ATM or Chk2 kinase activity by specific low-molecular-weight inhibitors restricted SRPK2 to the cytoplasm and conferred tolerance to cisplatin treatment. A similar effect was achieved by treating cells with SRPIN340, a selective SRPK1/2 inhibitor, thus confirming previous findings that kinase activity is indispensable for the nuclear import of SRPKs. These data add to previous findings that support a decisive role of SRPKs in coordinating cellular response to DNA damage.