Fig. 6.
The MEK 1/2 inhibitor PD98059 prevents both phosphorylation of LSF and activation of ERK activity in PHA-stimulated human peripheral T cells. A: T cells stimulated for the indicated amounts of time with PHA were either mock treated (lanes 1–4) or preincubated with 50 µM PD98059 (lanes 5–8). The blot of separated nuclear extracts (40 µg per lane) was probed with α-LSFpep1–2 antibody. The position of LSF is bracketed. Note the slight curvature across the lanes in the relative mobilities of the proteins. B: The blot from panel A was reprobed with anti-phospho ERK antibody. The positions of phosphorylated p44 and p42 are indicated. The asterisk denotes a non-specific, cross-reacting band.