Assertion: ligand's receptor | /r/CapableOf | span the cell membrane
Facets:
value: just once
type: TEMPORAL
value: usually
type: TEMPORAL
Source sentences:
text: Receptors as enzymes: These receptors usually span the cell membrane just once, and in response to binding of a ligand, usually increase the phosphorylation of intracellular proteins, for example the tyrosine residues on vital regulatory components (Occasionally, serine or threonine residues are phosphorylated).