Inhibition of GDP/GTP exchange on ARF-1 by M69.
(A) GDP/GTP-exchange activity of cytohesin 1, C1-Sec7,
C2-Sec7, and Gea2-Sec7 on ARF-1 in the presence of M69 (solid bars) and
unselected RNA library (shaded bars). The amount of bound
[γ35-S]GTP after 30 min without RNA was defined as
100%. (B) Concentration dependence of inhibition of
cytohesin 1-catalyzed GDP/GTP exchange on ARF-1 by M69 (■)
and unselected pool (♦). (C) Time course of inhibition
of cytohesin 1-catalyzed GDP/GTP exchange on ARF-1 by M69
(▴) vs. noninhibited negative control (■).
(D) GDP/GTP-exchange activity of cytohesin 1, C1-Sec7,
C2-Sec7, and Gea2-Sec7 on ARF-1 in the presence of BFA.