Identification and quantification of KPNA2 phosphorylation and interactome in response to hydrogen peroxide-induced oxidative stress

ABSTRACT: Karyopherin α 2 (KPNA2, importin α1) is involved in the nuclear import of proteins and participates in cellular processes and accumulates in the nucleus under cellular stresses including hydrogen peroxide-indeced oxidative stress via unknown mechanisms. We performed the immunoprecipitation assay and SILAC-based quantitative proteomic analysis in HeLa cells to reveal that hydrogen peroxide decreased the phosphorylation of KPNA2 at serine 62 (S62) and increased its interaction with nucleophosmin 1 (NPM1). Specifically, a reduction in phosphorylated S62 on KPNA2 was observed in the cytoplasmic fraction, but this phosphorylated KPNA2 was not detected in the nuclear fraction. We also identified fifty-four KPNA2-interacting proteins in the nuclear fraction. Among them, NPM1, RPLP0, and MYH9 interacted with KPNA2 in cells exposed to hydrogen peroxide but not in unstressed control cells. Furthermore, the subcellular fractionation, immunoprecipitation, western blotting, immunofluorescence assay, and qRT-PCR analyses were used to support a novel finding that S62 phosphorylation maintains KPNA2 in the cytoplasm, and hydrogen peroxide reduces the phosphorylation of KPNA2 S62 to promote KPNA2-NPM1 complex nuclear entry for gene regulation.

INSTRUMENT(S): LTQ Orbitrap Elite

ORGANISM(S): Homo Sapiens (human)

TISSUE(S): Permanent Cell Line Cell

DISEASE(S): Cervix Carcinoma

SUBMITTER: Chia-Jung Yu  

LAB HEAD: Chia-Jung Yu

PROVIDER: PXD051121 | Pride | 2024-10-17

REPOSITORIES: Pride