Sbh1p phosphorylation is dynamic. (A) SBH1Δsbh2 cells were labelled with [32P]phosphate for 10 min and chased for the indicated times. Cells were lysed, Sbh1p and Sec63p immunoprecipitated, proteins resolved by SDS-PAGE and detected by autoradiography (upper panels) and immunoblotting (lower panels). Signals were quantified using a phosphorimager and relative amounts of protein (yellow) and phosphoprotein (blue) shown in the graphs. (B) N-termini of Sbh1p homologues were aligned.