(a) 293T cells were co-transfected with plasmids encoding full-length FLAG-tagged LYRIC/AEG-1 with empty HA-vector (lanes1&4), HA-BCCIPc (lanes 2&5) or HA-BCCIPα (lanes 3&6). Expression was verified by Western blotting of cell lysates with anti-FLAG and anti-HA (lanes 1–3). FLAG-LYRIC was immunoprecipitated using anti-FLAG agarose (lanes 4–6, upper), and both isoforms of BCCIP co-precipitated (lanes 4–6, lower). (b) HA-BCCIPα (+) or empty vector (−) were transfected into 293T and endogenous LYRIC was IP’d using PAb5393. IP with pre-immune rabbit serum (IgG) was the negative control. BCCIPα co-precipitated with LYRIC (upper), and precipitation of LYRIC was confirmed by blotting with PAb5393 (lower). (c) HA-BCCIPα was transfected into 293T and IP’d with anti-HA agarose. Endogenous LYRIC co-precipitated and was detected with PAb5393.