Figure 2.

Coimmunoprecipitation of IGFBP-2 and PAPA-1 in LNCaP cells. LNCaP cells were transfected with myc-hPAPA-1 or myc vector control. IGFBP-2 bound to PAPA-1 was coimmunoprecipitated from 500 μg whole-cell extract (A) or subcellular fractions (B) by immunoprecipitation (IP) with IGFBP-2 or IgG control antibodies followed by immunoblotting (IB) for PAPA-1. Validity of fractionation was confirmed by immunoblot for HSP60 (cytoplasmic fraction, Cyto) and PARP (nuclear fraction, Nuc). Input refers to 20 μg whole-cell lysate or subcellular fraction used for coimmunoprecipitations, as described.