FIG. 5.

NSP5 is a substrate of CKII. Shown is SDS-PAGE analysis of an in vitro CKII phosphorylation assay with [γ-³²P]ATP. (A) The indicated GST-NSP5 mutants were used as substrates. Positive and negative controls are shown in lanes 1, 7, 8, and 9. −, no substrate added. (B) Purified, in vitro-translated ³⁵S-His₆-Δ1 was used as a substrate in the presence or absence of CKII. The two panels show autoradiography of the same gel, detecting ³⁵S plus ³²P (left) and ³²P (right). The solid and open arrowheads indicate His₆-Δ1 precursor and hyperphosphorylated forms, respectively. Autophosphorylated GST-α and GST-β CKII subunits are indicated. +, present; −, absent.