Coimmunoprecipitation of HA-Enigma and skeletal β-TM in transfected 293 cells. Proteins were expressed via transient transfection of 293 cells using the indicated pcDNA3 constructs: lane 1, skeletal β-TM; lane 2, skeletal β-TM and HA-tagged full-length Enigma; lane 3, skeletal β-TM and HA-tagged Enigma LIM domains (HA-EnigmaΔPDZ); lane 4, HA-tagged full-length Enigma; lane 5, HA-EnigmaΔPDZ; and lane 6, empty vector. Antibodies against the HA epitope were used to coprecipitate HA-Enigma with associated proteins. (A) Anti-TM Western blot indicates that skeletal β-TM associates with HA-Enigma (lane 2) but not with HA-EnigmaΔPDZ (lane 3). (B) Anti-TM Western blot of transfected cell lysates before immunoprecipitation (2% of input). (C) The blot in A was stripped and reprobed with anti-HA antibodies. Bands at ∼56 and ∼25 kDa indicate that both HA-Enigma (lanes 2 and 4) and HA-EnigmaΔPDZ (lanes 3 and 5) were immunoprecipitated by the anti-HA antibodies.