Agrin in Postsynaptic Differentiation
The heparan sulphate proteoglycan agrin is well known as the key assembly factor of postsynaptic differentiation at the neuromuscular junction (NMJ), but recent data suggest it also plays a direct role in the organization of the cytoskeleton in the skeletal muscle. Signaling through muscle-specific proteins such as muscle specific kinase (MuSK) and or acetylcholine receptor (AchRs)/rapsyn, agrin can activate ubiquitously expressed Rac, Cdc42, and p21-activated kinase (PAK) that are involved in actin polymerization. Agrin also engages signaling pathways of several potent oncogenes (i.e., SFK, ErbB receptors, and cortactin).
Contributor: Kosi Gramatikoff, PhD
REFERENCES: Bezakova G, Ruegg MA. New insights into the roles of agrin. Nat Rev Mol Cell Biol. 2003 Apr;4(4):295-308. Moll J et al. An agrin minigene rescues dystrophic symptoms in a mouse model for congenital muscular dystrophy. Nature. 2001 Sep 20;413(6853):302-7.
