N-glycosylation of JIP21. Two micrograms of JIP21 purified protein, ovoalbumin (OA), used as a positive control, and bovine serum albumin (BSA), used as a negative control, were separated in 14% SDS-PAGE. A, Proteins stained with Coomassie Brilliant Blue R-250. B, Proteins transferred onto Immobilon membrane and stained with Ponceau-S. C, Proteins transferred onto Immobilon membrane and stained with periodic acid-Schiff reagent. Lane M, Mr standards.