Calpastatin phosphorylation regulates radiation-induced calpain activity in glioblastoma.

ABSTRACT: Glioblastoma (GBM) is an aggressive, malignant brain tumor that inevitably develops resistance to conventional chemotherapy and radiation treatments. In order to identify signaling pathways involved in the development of radiation resistance, we performed mass spectrometry-based phospho-proteomic profiling of GBM cell lines and normal human astrocytes before and after radiation treatment. We found radiation induced phosphorylation of a number of proteins including calpastatin, specifically in GBM stem cells (GSCs). Herein, we focused on calpastatin, an endogenous inhibitor of calpain proteases. Radiation-induced phosphorylation of calpastatin at Ser-633 within the inhibitory domain was validated with a phospho-specific antibody. In order to test the functional significance of phosphorylate

SUBMITTER: Bassett EA 

PROVIDER: S-EPMC5865692 | biostudies-literature | 2018 Mar

REPOSITORIES: biostudies-literature