Fig. 4.

CIRP co-precipitates with HuR. A, GST pull-down assay: GST or GST-CIRP was incubated with MCF-7 cell extract. GST-CIRP was pulled down with Glutathione-Sepharose and eluted proteins immunoblotted for HuR. B, MCF-7 cell extract treated with or without RNase A was incubated with CIRP antibody (α-CIRP) or normal IgG followed by protein A/G agarose beads. The co-precipitated proteins eluted from the beads (Beads) were resolved on a 10% SDS-polyacrylamide gel and immunoblotted for CIRP or HuR. The supernatants (Sup) were immunoblotted for β-actin to monitor equal amounts of starting protein. Experiments were repeated at least 3 times.