Electrophoretic mobility shift assay demonstrated that hnRNP A1DC retained the ability to bind the MHV (±)strand leader RNA and to form multimers with itself, similar to the wt hnRNP A1 (data not shown); this is consistent with the fact that both of its RBDs are intact ( Figure 1A) . Furthermore, UV-crosslinking experiments showed that increasing amounts of puri®ed glutathione S-transferase (GST)±hnRNP A1DC ef®ciently competed with the endogenous hnRNP A1 for the binding of the MHV (±)-strand leader RNA ( Figure 7A ), indicating that the binding of hnRNP A1DC to RNA was not affected. These results suggest that the RNA-binding properties of hnRNP A1DC were intact.