Fig. 7.

ADAM metalloproteinases can influence autocrine, paracrine and juxtacrine signalling. The schematic depicts the potential actions of ADAMs (scissors) on receptor–ligand pairs, acting to release ligand that acts upon receptors on the cell of origin (autocrine), or on distant cells (paracrine). Juxtacrine signalling involving adjacent cells may involve ADAMs for correct presentation of the ligand, or for cleavage of the ligand following receptor engagement, or for receptor activation. Shed receptors may act as decoys, or cleavage of the receptor may itself activate or modulate signalling.