Rsp5p associates with the membrane fraction of a
cell lysate. (A) Differential centrifugation of a lysate prepared from
cells expressing HA-Rsp5p (LHY2066). LHY2066 cells were propagated at
24°C in YPUA galactose medium; 13,000 × g (P13),
100,000 × g (P100), and soluble (S) cell fractions
were resolved by SDS-PAGE, transferred to nitrocellulose, and probed
with HA antibodies. (B) Differential centrifugation after biochemical
treatments. LHY896 cells were grown in YPUAD medium at 30°C. The cell
lysate was mock (buffer) treated, treated with 2.5 M urea, or treated
with 1.0% (vol/vol) Triton X-100 (TX100) and 0.2% (wt/vol) dodecyl
β-d-maltoside (β-DM) for 1 h on ice before
fractionation. Fractions were analyzed as in A by
immunoblotting with HA, c-myc, or hexokinase antibodies
to detect HA-Rsp5p, myc-Emp47p, and hexokinase, respectively. An
equivalent amount of the total cell extract is shown for comparison.
SUP, supernatant.