FIGURE 9:

Ubiquitin is present in immunoprecipitated endogenous CD98 complexes in MARCH8-expressing cells. HeLa cells were transfected with MARCH3-FLAG or MARCH8-FLAG with or without HA-ubiquitin. After 18 h, CD98 was immunoprecipitated from whole-cell lysates as described in Materials and Methods. Ten percent of whole-cell lysates were immunoblotted with anti-CD98 antibodies (lanes 1–4). Molecular weights are identified in kDa. CD98 immunoreactive bands were detected at ∼90 and 110 kDA. Twenty percent of recovered CD98 immunoprecipitates were immunoblotted with anti-CD98 or anti-HA antibodies (lanes 5–8). Two HA-reactive bands were present in the MARCH8-expressing CD98 immunoprecipitates (lane 8 arrows).