G -> G_a
G + HRP1 -> G_a + HRP1
G + HR -> G_a + HR
G_a + PIP2 -> DAG + G_a
DAG + PKC -> DAG + PKC_a
ERK + PKC_a -> GpERK + PKC_a
G_a -> G
DAG -> PIP2
PKC_a -> PKC
GpERK -> ERK
HR -> HRP1
HRP1 + barr1 -> Hbarr1RP1
Hbarr1RP1 -> HRP1 + barr1
HRP1 + barr2 -> Hbarr2RP1
Hbarr2RP1 -> HRP1 + barr2
Hbarr1RP1 -> HR + barr1
Hbarr2RP1 -> HR + barr2
HR -> HRP2
HRP2 -> HR
HR + barr2 -> HRbarr2
HRbarr2 -> HR + barr2
HRP2 + barr2 -> Hbarr2RP2
Hbarr2RP2 -> HRP2 + barr2
ERK + HRbarr2 -> HRbarr2 + bpERK
ERK + Hbarr2RP2 -> Hbarr2RP2 + bpERK
bpERK -> ERK