Agrin is a multidomain heparan sulphate proteoglycan, that is a key organiser for the induction of postsynaptic specialisations at the neuromuscular junction. Binding of agrin to basement membranes requires the amino terminal (NtA) domain [2]. This region mediates high affinity interaction with the coiled-coil domain of laminins. The binding of agrin to laminins via the NtA domain is subject to tissue-specific regulation. The NtA domain-containing form of agrin is expressed in non-neuronal cells or in neurons that project to non-neuronal cell such as motor neurons. The structure of this domain is an OB-fold [1].

1: The laminin-binding domain of agrin is structurally related to N-TIMP-1. Stetefeld J, Jenny M, Schulthess T, Landwehr R, Schumacher B, Frank S, Ruegg MA, Engel J, Kammerer RA; Nat Struct Biol 2001;8:705-709. PMID:11473262

2: Synaptic differentiation: the role of agrin in the formation and maintenance of the neuromuscular junction. Denzer AJ, Hauser DM, Gesemann M, Ruegg MA; Cell Tissue Res 1997;290:357-365. PMID:9321698