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Fig. 2. Transport motifs bind to COPII components in vitro. Peptides comprising the
sequence of ERGIC-53 tail with the indicated C-terminal motifs were coupled to
thiol-activated Sepharose. The beads were incubated with detergent lysates of
HepG2 cells. Bound proteins were separated by SDS-PAGE, and nitrocellulose
blots were probed for COPII binding using antibodies against COPII subunits.
(A) A binding assay with peptides bearing double substitutions at XX position.
(B) A binding assay with peptides bearing single motifs. Lane C: lysate
corresponding to one quarter of the amount incubated with peptide beads.
Representative examples of at least three independent experiments are
shown.