Following viral infection, serine 990, located in the WHEP linker, is phosphorylated to release EPRS from the MSC, after which the amino-terminal domain of EPRS (1–196 aa), which contains a GST-like domain (1–168 aa) and the linker region L1 (168–196 aa), interacts with poly(rC)-binding protein 2 (PCBP2). Here, PCBP2 is linked to viral infectious disease.