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. 2006 Dec 7;35(1):175–185. doi: 10.1093/nar/gkl1034

Figure 1.

Figure 1

Interaction of TBP with CDX1 but not with CDX2. (A) Specific co-immunoprecipitation of TBP and HA-CDX1. HCT116 cells were co-transfected with the plasmids encoding TBP and either HA-CDX1, HA-CDX2 or the control empty vector, as indicated. Proteins immunoprecipitated with anti-HA antibody were detected by western blots using anti-HA to control the immunoprecipitation step and anti-TBP antibody to detect the co-immunoprecipitation of TBP. TBP was recovered in the fraction immunoprecipitated with HA-CDX1 but not with HA-CDX2. The presence of TBP in the cell extracts prior to HA-immunoprecipitation was controlled by western blot using anti-TBP antibody (Input). (B) Specific GST-pulldown of overexpressed TBP with GST-CDX1. HCT116 cells were co-transfected with the plasmids encoding TBP and either GST-CDX1, GST-CDX2 or the control GST vector, pBC. GST-pulldown extracts were analyzed by western blots using anti-GST antibody and assayed for the presence of TBP using anti-TBP antibody. TBP was recovered in the fraction containing GST-CDX1 but not GST-CDX2. The presence of TBP in the cell extracts prior to GST-pulldown was controlled by western blot using anti-TBP antibody (Input). The lower panel demonstrates overexpression of TBP in total extracts of HCT116 cells transfected with the TBP-encoding plasmid as compared to cells transfected with the empty vector. (C) Specific co-immunoprecipitation of endogenous TBP by HA-CDX1. HepG2 cells were transfected with the plasmids encoding HA-CDX1, HA-CDX2 or the control plasmid. Immunoprecipitation was performed as described in A with anti-HA antibody followed by western blot analysis with anti-HA or anti-TBP. HA-CDX1, but not HA-CDX2, was able to interact with endogenous TBP. The presence of TBP in the cell extracts prior to HA-immunoprecipitation was controlled by western blot using anti-TBP antibody (Input).