Fig. 1.

Subcellular localization of XOR. (a) Coimmunoprecipitation demonstrates association between NOS1 and XOR proteins. XOR coimmunoprecipitates with NOS1 (bands 1, 4, and 7) but not with NOS3 (bands 3, 6, or 9). The lysate bands (bands 2, 5, and 8) represent total heart protein extract revealing little XOR protein. (b) Purified SR fractions were probed with anti-XOR, anti-SERCA2a, and anti-NOS1 antibodies. As depicted, the 150-kDa monomer of XOR appears in the SR, with highest intensity in lane 4. Both NOS1 and SERCA2a are identified in the same fractions. TP, total heart protein; M, microsomal fraction; RC, rat cerebellum.