Agrin (AGRN) ELISA Kit for Rat

Isoform 1: heparan sulfate basal lamina glycoprotein that plays a central role in the formation and the maintenance of the neuromuscular junction (NMJ) and directs key events in postsynaptic differentiation. Component of the AGRN-LRP4 receptor complex that induces the phosphorylation and activation of MUSK. The activation of MUSK in myotubes induces the formation of NMJ by regulating different processes including the transcription of specific genes and the clustering of AChR in the postsynaptic membrane. Calcium ions are required for maximal AChR clustering. AGRN function in neurons is highly regulated by alternative splicing, glycan binding and proteolytic processing. Modulates calcium ion homeostasis in neurons, specifically by inducing an increase in cytoplasmic calcium ions. Functions differentially in the central nervous system (CNS) by inhibiting the alpha(3)-subtype of Na+/K+-ATPase and evoking depolarization at CNS synapses.Isoform 9: transmembrane agrin (TM-agrin), the predominant form in neurons of the brain, induces dendritic filopodia and synapse formation in mature hippocampal neurons in large part due to the attached glycosaminoglycan chains and the action of Rho-family GTPases.Isoform 2, isoform 4 and isoform 7: muscle agrin isoforms, which lack the 8-amino acid insert at the 'B' site, but with the insert at the'A' site have no AChr clustering activity nor MUSK activation but bind heparin. Bind alpha-dystroglycan with lower affinity.Isoform 5: muscle agrin A0B0 lacking inserts at both 'A' and 'B' sites has no heparin-binding nor AChR clustering activity but binds strongly alpha-dystroglycan.Agrin N-terminal 110 kDa subunit: is involved in modulation of growth factor signaling (). Involved also in the regulation of neurite outgrowth probably due to the presence of the glycosaminoglcan (GAG) side chains of heparan and chondroitin sulfate attached to the Ser/Thr- and Gly/Ser-rich regions. Also involved in modulation of growth factor signaling.