Figure 4.

Immunoblots of yeast lysate fractions. (A) Fractionation of wild-type and mutant Gga proteins. Total lysates (T) from strains expressing HA-tagged Gga2p, Gga1p, Gga2p^I207N, or Gga1p^L203Q were centrifuged at 100,000 × g to generate supernatant (S) and pellet (P) fractions. Duplicate gels were probed with antibodies to the HA tag (top) or Arf1p (bottom). Arf1p was predominantly in the soluble fraction, whereas all Gga proteins fractionated equally between the soluble and pellet fractions. (B) Fractionation of Gga2p in the absence of Arf1p. Fractions from wild-type or arf1Δ strain TT104 were prepared as in A, and probed with antibodies to Gga2p. Gga2p was predominantly in the pellet fraction in both strains.