Figure 4.

p28-containing inner dynein arms are associated with part of the 17S complex in the cytoplasmic matrix. (a) Electrophoretograms of subunits of the 17S complex contained in chromatographic fractions that were eluted from a 0.3 ml DEAE-Sepharose (fast flow; Pharmacia) column. Elution was performed by a 4 ml 0.03–0.4 M NaCl gradient in 0.01 M Hepes (pH 6.8). Molecular weight standards are indicated on the left. Lines between lanes 24 and 25 indicate the presence of components 1–13 of the 17S complex. (b and c) Western blots of polypeptides by antibodies specific for p28. (b) Western blot of fractions that are shown in a. (c) Western blot of 11S inner dynein arms that were subjected to DEAE-Sepharose column chromatography as described in a. (d) Electrophoretograms of polypeptides that were precipitated from a sucrose gradient fraction containing the 17S complex. Lane 1 (indicated as −) shows polypetides precipitated by the protein A-agarose beads in the absence of antibodies. Lane 2 (indicated as +) shows polypetides precipitated by the protein A-agarose beads in the presence of antibodies specific for p28. Dynein heavy chains (HC), actin, and p28 that are present in the immunoprecipitate are indicated on the right.