Fig. 6. LUMA oligomerization. (A) HeLa cells were transfected with full-length LUMA 1-400 together with truncation mutants. Full-length LUMA was immunoprecipitated with anti-V5 antibody, and the precipitate analyzed for the presence of truncation mutants with either anti-LUMA antibody (lanes 1-8) or anti-Myc antibody (lanes 9 and 10). LUMAe, endogenous LUMA; , higher molecular mass bands of LUMA; HC, IgG heavy chain; LC, IgG light chain; , LUMA 53-309 and a fragment from LUMA 1-309. (B) Full-length LUMA 1-400, LUMAgal and LUMA 53-309 were ³⁵S-labeled by coupled in vitro transcription and translation in the presence of microsomes. The resulting hetero- and homooligomers were separated by BN gel electrophoresis in the presence or absence of SDS. The complexes were further resolved by second dimension SDS-PAGE and visualized by autoradiography. , SDS-resistant, low-molecular-mass complex of LUMA 1-400; , LUMA 1-400; , LUMAgal; , LUMA 53-309.