Secretory Voted. idles containing alchol N Cell body of postsynaptic neuron Action
HO CH2CH2NHs Serotonin (5-Hydroxytryptamine)
COo H2N一CH CH2 CHa COO Glutamate
Insulin bound to ptor sites xtracellular space ATP Tyrosine T ki ( Tyr domains Autophos phorylatio Carboxyl-terminal site Target TyT-ADP Intracellular Cytosol
① Insulin receptor binds Insulin insulin and undergoe autophosphorylation on its T carboxyl-terminal Tyr residues Insulin receptor phosphorylates IRS-1 on its Tyr residues. SH2 domain of grb2 binds to(P-Tyr of IRS-I Sos binds IRS1 to grb2. then to ras causing GDP release and Cytosol GDP GTP binding to Ras. GTP ④ Activated ras binds and MEK activates Raf-1 Nucleus MEK on two Ser residues activating it. MEH MAPK MAPk phosphorylates MAPK CMAPK) on a Thr and a Tyr residue. activating it. MAPK moves into SRPEIkLP the nucleus and DNA phosphorylates nuclear transcription factors such as Elkl New proteins activating th Phosphorylated Elkl joins SRF to stimulate he transcription and translation of a set of genes needed for cell division