Figure 2.

p21^cip1 interacts with p34^cdc2/cyclin complexes and does not inhibit the MAPK pathway. (A–D) Recovery of complexes bound to p21^cip1. Thirty prophase (P) or metaphase II (MII) oocytes were microinjected or not with p21^cip1 to an internal concentration of 1 μM and cultured for 1 h. After homogenization of oocytes, glutathione-agarose beads were added to the clear supernatant. Beads were washed, and bound proteins were electrophoresed and subjected to Western blot analysis for p34^cdc2 (A), cyclin B1 (B), cyclin B2 (C), and cyclin A (D). (E) Effect of p21^cip1 on the MAPK electrophoretic mobility shift induced by injection of MBP-Mos. Twenty prophase oocytes were microinjected or not with p21^cip1 (1 μM). One hour later, they were microinjected with 50 μg of recombinant MBP-Mos or treated with progesterone (Pg). Oocytes were collected at the time of 100% GVBD in MBP-Mos–injected oocytes. An amount equivalent to three oocytes was subjected to Western blot analysis for MAPK.