• Results from experimental autoimmune MG animal models indicate that anti-LRP4 antibodies are causal to MG. Clinical studies have begun to reveal the significance of the new biomarkers. (nih.gov)
  • Recently his team has led three international studies (laboratories and clinics from 13 countries with sera from ~800 'seronegative' MG patients for the extensive study of anti-LRP4 antibodies (Zisimopoulou et al. (neurodiagnostics.gr)
  • Agrin functions by activating the MuSK protein (for Muscle-Specific Kinase), which is a receptor tyrosine kinase required for the formation and maintenance of the neuromuscular junction. (wikipedia.org)
  • Agrin is required to activate MuSK. (wikipedia.org)
  • In addition to MuSK, agrin binds several other proteins on the surface of muscle, including dystroglycan and laminin. (wikipedia.org)
  • The requirement for Agrin and MuSK in the formation of the NMJ was demonstrated primarily by knockout mouse studies. (wikipedia.org)
  • The nerve secretes agrin, resulting in phosphorylation of the MuSK receptor. (wikipedia.org)
  • Since agrin fragments induce acetylcholine receptor aggregation as well as phosphorylation of the MuSK receptor, researchers spliced them and found that the variant did not trigger phosphorylation. (wikipedia.org)
  • Recruitment of AGRIN by LRP4 to the MUSK signaling complex induces phosphorylation and activation of MUSK, the kinase of the complex. (calixar.com)
  • The role of agrin, Lrp4 and MuSK during dendritic arborization and synaptogenesis in cultured embryonic CNS neurons. (mdc-berlin.de)
  • When secreted, agrin binds to several receptors on the surface of skeletal muscle. (wikipedia.org)
  • These, namely, are agrin or low-density lipoprotein receptor-related protein 4 (LRP4), which may be the cause of the disease. (myastheniagravisnews.com)
  • During development in humans, the growing end of motor neuron axons secrete a protein called agrin. (wikipedia.org)
  • There are three potential heparan sulfate (HS) attachment sites within the primary structure of agrin, but it is thought that only two of these actually carry HS chains when the protein is expressed. (wikipedia.org)
  • Heparan sulfate glycosaminoglycans covalently linked to the agrin protein have been shown to play a role in the clustering of AChR. (wikipedia.org)
  • It may be that rather than solely binding directly to the agrin protein core a number of components of the secondary scaffold may also interact with its heparan sulfate side-chains. (wikipedia.org)
  • A role in the retention of anionic macromolecules within the vasculature has also been suggested for agrin-linked HS at the glomerular or alveolar basement membrane. (wikipedia.org)
  • Agrin may play an important role in the basement membrane of the microvasculature as well as in synaptic plasticity. (wikipedia.org)