Fig. 4. Molecular complexes identified in junctional plaques present in cytoskeletal fractions from lens fibers, as identified by immunoprecipitations followed by SDS-PAGE (6%), immunoblotting and MALDI-MS. (a) Coomassie-Blue-stained proteins present in immunoprecipitates from water-insoluble, 1%-Triton-X-100-soluble fractions from bovine lens fiber cells. (Lane 1) Major proteins of the supernatant used for immunoprecipitation are indicated by symbols on the left margin (from top): [spectrin/fodrin,
filensin, and
ezrin (81 kDa). (Lane 2) Immunoprecipitate obtained with the monoclonal ezrin antibody 3C12, showing from top:
desmoyokin (>600 kDa),
periplakin (
190 kDa), [periaxin (two bands of
170 kDa and
150 kDa) and
ezrin. (Lane 3) Immunoprecipitation with rabbit antibodies against desmoyokin (IP Dy), showing (from top):
desmoyokin,
periplakin and [periaxin. (Lane 4) Immunoprecipitate obtained with guinea pig antibodies against desmoyokin (IP Dy), showing (from top):
desmoyokin,
periplakin, together with
and
guinea pig immunoglobulin chains. (Lane 5) Immunoprecipitate obtained with guinea pig antibodies against periplakin (IP Ppl):
desmoyokin and
periplakin, together with
and
guinea pig immunoglobulin chains. (b) Immunoprecipitate obtained with ezrin antibody [as in (a), lane 2] was subjected to SDS-PAGE and probed with antibodies against periplakin (lane 1; Ppl), desmoyokin (lane 2; Dy), spectrin/fodrin (lane 3; Spec), showing the presence of these proteins in the immunoprecipitated ezrin complexes. Controls of proteins bound to blank Sepharose and to Sepharose coated with antibodies to desmoplakins or desmocollins were negative. Molecular weight markers are indicated on the left.