AAA cassettes of Pex1p and Pex6p are involved in the dissociation of the Pex26p·Pex14p complex.
A, FLAG-Pex26p was expressed in pex1 ZP107 together with Pex1p-HA and Pex6p-HA (lane 1) as well as Pex14p (lane 2) as indicated at the top. AAA cassette mutants of Pex6p were expressed in pex6 ZP164 together with FLAG-Pex26p, Pex1p-HA, and Pex14p (lanes 8–10). Proteins recovered with anti-FLAG antibody-conjugated beads were analyzed by SDS-PAGE and immunoblotting with antibodies to Pex26pC (IP, upper panel), HA (IP, middle panel), and Pex14pC (IP, lower panel). Input, 5% input. B, Pex14p bound to FLAG-Pex26p was quantified by densitometric scanning, normalized as a ratio of Pex14p to Pex26p density, and represented by taking as 1 that in the absence of Pex1p·Pex6p (lane 2). Filled column, Pex14p. Values are the means ± S.D. from three experiments.