Scaffold protein that plays an essential role in cytoplasmic stress granule formation which acts as a platform for antiviral signaling. Forms homooligomers (PubMed:23279204). Forms heterodimers with G3BP1 (PubMed:23279204). Interacts with NFKBIA (via N-terminus) (PubMed:10969074). Interacts with USP10 (PubMed:23279204). Interacts with PABPC1 (PubMed:23279204). (Microbial infection) Interacts with Sindbis virus non-structural protein 3 (via C-terminus); this interaction inhibits the formation of host stress granules on viral mRNAs and the nsp3-G3BP2 complexes bind viral RNAs and probably orchestrate the assembly of viral replication complexes. Arg-457 and Arg-468 are dimethylated, probably to asymmetric dimethylarginine. (Microbial infection) Cleaved by foot-and-mouth disease virus leader protease; this cleavage suppresses the formation of cytoplasmic stress granules.