Implication of RPA32 phosphorylation in S-phase checkpoint signalling at replication forks stalled with aphidicolin in Xenopus egg extracts

► Phosphorylation mutants of RPA32 both nucleate at replication forks arrested with aphidicolin. ► RPA32 phosphomimetic mutant DOES NOT stimulate activation of the replication checkpoint. ► RPA32 kDa phosphorylation mutants do not interfere with DNA synthesis.