Label-Free Protein-RNA Interactome Analysis Identifies Khsrp Signaling Downstream of the p38/Mk2 Kinase Complex as a Critical Modulator of Cell Cycle Progression
Fig 4
Mk2/3-dependent regulation of Khsrp and Cdkn1ap21.
(A) Mk2-/-;Mk3-/- cells show a differential protein-RNA interactome in response to etoposide exposure when compared to wildtype cells (most-significant changes are highlighted). (B) Khsrp RNA immunoprecipitations (RIP) followed by Cdkn1aP21 qPCR validates interactome changes seen in wildtype and Mk2-/-;Mk3-/- cells upon etoposide treatment. Upon etoposide exposure Khsrp is released from Cdkn1aP21 transcripts. In contrast, in Mk2-/-;Mk3-/- MEFs, Khsrp-bound Cdkn1aP21 transcripts increase upon etoposide exposure. (C) Despite a typical arrest in G2 upon etoposide treatment, (D) Mk2-/-;Mk3-/- MEFs show a decreased G1 population in comparison to wt cells. (E) Increased levels of the Cdkn1aP21 transcript in Mk2-/-;Mk3-/- cells upon etoposide treatment (F) fail to promote the upregulation of Cdkn1aP21 protein levels seen in wildtype cells.