As part of the heterotrimeric replication protein A complex (RPA/RP-A), binds and stabilizes single-stranded DNA intermediates, that form during DNA replication or upon DNA stress. It prevents their reannealing and in parallel, recruits and activates different proteins and complexes involved in DNA metabolism. Thereby, it plays an essential role both in DNA replication and the cellular response to DNA damage. Component of the replication protein A complex (RPA/RP-A), a heterotrimeric complex composed of RPA1, RPA2 and RPA3. Redistributes to discrete nuclear foci upon DNA damage in an ATR-dependent manner. Differentially phosphorylated throughout the cell cycle, becoming phosphorylated at the G1-S transition and dephosphorylated in late mitosis. Phosphorylation increases upon replication fork stalling (By similarity). Belongs to the replication factor A protein 2 family.