AMPK activates autophagy by directly and indirectly activating ULK1. Natural killer cell activation is determined by the balance of inhibitory and activating receptor stimulation. These proteins allow caspase-1 activation by forming a multiprotein activating complex called Inflammasomes. Glutamate exerts its effects by binding to and activating cell surface receptors. Dopamine exerts its effects by binding to and activating cell surface receptors. Nicotine also counteracts anticholinergics by activating nicotinic acetylcholine receptors. Silent antagonists are competitive receptor antagonists that have zero intrinsic activity for activating a receptor. Inhibition of one hotspot results in the blunting of the effects of activating another hotspot. The dimer is responsible for activating the kinase JAK via binding. Clobetasol is believed to work by activating steroid receptors. The APC involved in activating T cells is usually a dendritic cell. The proenzymes are cleaved, creating a cascade of activating enzymes. There are 2 distinct subgroups of TI antigens, different in mechanism of activating B lymphocytes. Activating and repressing sites overlap in sequence. This amplifies the effect of activating glycogen phosphorylase.