Activated p38 MAP kinase has been shown to phosphorylate and activate MAPKAP kinase 2 and to phosphorylate the transcription factors ATF2, Mac,  MEF2, and p53.
The passage describes the effects of activated p38 MAP kinase on several key proteins involved in cellular signaling and gene regulation: MAPKAP kinase 2, and transcription factors ATF2, Mac, MEF2, and p53.