1. The role of CK2 in IGFBP-5 phosphorylation
The role of CK2 in IGFBP-5 phosphorylation.a, metabolic labeling of T47D breast carcinoma cells using [32P]orthophosphoric acid in the absence or presence of either 0.01 or 0.1 mm DRB. IGFBP-5 was extracted from media on IGF-I-agarose and subjected to SDS-PAGE and Western immunoblotting (WIB) followed by autoradiography (AR). b, subsequent densitometry analysis was used to quantitate the effect of including DRB, internally normalized to immunostaining.
The role of CK2 in IGFBP-5 phosphorylation.a, metabolic labeling of T47D breast carcinoma cells using [32P]orthophosphoric acid in the absence or presence of either 0.01 or 0.1 mm DRB. IGFBP-5 was extracted from media on IGF-I-agarose and subjected to SDS-PAGE and Western immunoblotting (WIB) followed by autoradiography (AR). b, subsequent densitometry analysis was used to quantitate the effect of including DRB, internally normalized to immunostaining. Data are the mean of three independent experiments, performed in duplicate, expressed as a percentage of the 16-h control. (▪, 0 mm DRB; •, 0.01 mm DRB; ♦, 0.1 mm DRB). c, IGFBP-5 is a substrate for CK2 in vitro. IGFBP-5 (untreated, lanes 1 and 2; Antarctic phosphatase (AP)-treated, lanes 3 and 4) was incubated with [γ-32P]ATP in the absence (lanes 1 and 3) or presence (lanes 2 and 4) of CK2 and analyzed by both Western immunoblotting (WIB) and autoradiography (AR). Lane 5 illustrates the autophosphorylation of CK2 in the absence of IGFBP-5.
Mark E. Graham et al. Mol Cell Proteomics 2007;6:
© 2007 The American Society for Biochemistry and Molecular Biology