0 -> cyclin
cyclin -> 0
cdc2 + cyclin -> dimer
dimer_p -> dimer
dimer -> p_dimer
dimer -> dimer_p
dimer -> 0
p_dimer -> dimer
p_dimer -> p_dimer_p
p_dimer -> 0
p_dimer_p -> p_dimer
dimer_p -> p_dimer_p
p_dimer_p -> dimer_p
p_dimer_p -> 0
dimer_p -> 0
cdc25 -> cdc25_p
cdc25_p -> cdc25
wee1 -> wee1_p
wee1_p -> wee1
IE -> IE_p
IE_p -> IE
UbE -> UbE_star
UbE_star -> UbE