| Structural highlights
Function
[AGRIN_CHICK] 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 funtion in neurons is highly regulated by alternative splicing, glycan binding and proteolytic processing. Modulates calcium ion homestasis 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.[1] [2] [3] [4] [5] [6] [7] 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.[8] [9] [10] [11] [12] [13] [14] 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.[15] [16] [17] [18] [19] [20] [21] 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.[22] [23] [24] [25] [26] [27] [28] Agrin N-terminal 110 kDa subunit: is involved in modulation of growth factor signaling (By similarity). 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.[29] [30] [31] [32] [33] [34] [35] Agrin C-terminal 22 kDa fragment: this released fragment is important for agrin signaling and to exert a maximal dendritic filopodia-inducing effect. All 'B' splice variants of this fragment also show an increase in the number of filopodia.[36] [37] [38] [39] [40] [41] [42]
Evolutionary Conservation
Check, as determined by ConSurfDB. You may read the explanation of the method and the full data available from ConSurf.
Publication Abstract from PubMed
The aggregation of acetylcholine receptors on postsynaptic membranes is a key step in neuromuscular junction development. This process depends on alternatively spliced forms of the proteoglycan agrin with "B-inserts" of 8, 11, or 19 residues in the protein's globular C-terminal domain, G3. Structures of the neural B8 and B11 forms of agrin-G3 were determined by X-ray crystallography. The structure of G3-B0, which lacks inserts, was determined by NMR. The agrin-G3 domain adopts a beta jellyroll fold. The B insert site is flanked by four loops on one edge of the beta sandwich. The loops form a surface that corresponds to a versatile interaction interface in the family of structurally related LNS proteins. NMR and X-ray data indicate that this interaction interface is flexible in agrin-G3 and that flexibility is reduced by Ca(2+) binding. The plasticity of the interaction interface could enable different splice forms of agrin to select between multiple binding partners.
Modulation of agrin function by alternative splicing and Ca2+ binding.,Stetefeld J, Alexandrescu AT, Maciejewski MW, Jenny M, Rathgeb-Szabo K, Schulthess T, Landwehr R, Frank S, Ruegg MA, Kammerer RA Structure. 2004 Mar;12(3):503-15. PMID:15016366[43]
From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine.
References
- ↑ Gesemann M, Denzer AJ, Ruegg MA. Acetylcholine receptor-aggregating activity of agrin isoforms and mapping of the active site. J Cell Biol. 1995 Feb;128(4):625-36. PMID:7860635
- ↑ Bezakova G, Helm JP, Francolini M, Lomo T. Effects of purified recombinant neural and muscle agrin on skeletal muscle fibers in vivo. J Cell Biol. 2001 Jun 25;153(7):1441-52. PMID:11425874
- ↑ Baerwald-de la Torre K, Winzen U, Halfter W, Bixby JL. Glycosaminoglycan-dependent and -independent inhibition of neurite outgrowth by agrin. J Neurochem. 2004 Jul;90(1):50-61. PMID:15198666 doi:http://dx.doi.org/10.1111/j.1471-4159.2004.02454.x
- ↑ Scotton P, Bleckmann D, Stebler M, Sciandra F, Brancaccio A, Meier T, Stetefeld J, Ruegg MA. Activation of muscle-specific receptor tyrosine kinase and binding to dystroglycan are regulated by alternative mRNA splicing of agrin. J Biol Chem. 2006 Dec 1;281(48):36835-45. Epub 2006 Sep 29. PMID:17012237 doi:http://dx.doi.org/10.1074/jbc.M607887200
- ↑ Sallum CO, Kammerer RA, Alexandrescu AT. Thermodynamic and structural studies of carbohydrate binding by the agrin-G3 domain. Biochemistry. 2007 Aug 21;46(33):9541-50. Epub 2007 Jul 25. PMID:17649979 doi:http://dx.doi.org/10.1021/bi7006383
- ↑ Porten E, Seliger B, Schneider VA, Woll S, Stangel D, Ramseger R, Kroger S. The process-inducing activity of transmembrane agrin requires follistatin-like domains. J Biol Chem. 2010 Jan 29;285(5):3114-25. doi: 10.1074/jbc.M109.039420. Epub 2009 , Nov 25. PMID:19940118 doi:http://dx.doi.org/10.1074/jbc.M109.039420
- ↑ Patel TR, Butler G, McFarlane A, Xie I, Overall CM, Stetefeld J. Site specific cleavage mediated by MMPs regulates function of agrin. PLoS One. 2012;7(9):e43669. doi: 10.1371/journal.pone.0043669. Epub 2012 Sep 11. PMID:22984437 doi:http://dx.doi.org/10.1371/journal.pone.0043669
- ↑ Gesemann M, Denzer AJ, Ruegg MA. Acetylcholine receptor-aggregating activity of agrin isoforms and mapping of the active site. J Cell Biol. 1995 Feb;128(4):625-36. PMID:7860635
- ↑ Bezakova G, Helm JP, Francolini M, Lomo T. Effects of purified recombinant neural and muscle agrin on skeletal muscle fibers in vivo. J Cell Biol. 2001 Jun 25;153(7):1441-52. PMID:11425874
- ↑ Baerwald-de la Torre K, Winzen U, Halfter W, Bixby JL. Glycosaminoglycan-dependent and -independent inhibition of neurite outgrowth by agrin. J Neurochem. 2004 Jul;90(1):50-61. PMID:15198666 doi:http://dx.doi.org/10.1111/j.1471-4159.2004.02454.x
- ↑ Scotton P, Bleckmann D, Stebler M, Sciandra F, Brancaccio A, Meier T, Stetefeld J, Ruegg MA. Activation of muscle-specific receptor tyrosine kinase and binding to dystroglycan are regulated by alternative mRNA splicing of agrin. J Biol Chem. 2006 Dec 1;281(48):36835-45. Epub 2006 Sep 29. PMID:17012237 doi:http://dx.doi.org/10.1074/jbc.M607887200
- ↑ Sallum CO, Kammerer RA, Alexandrescu AT. Thermodynamic and structural studies of carbohydrate binding by the agrin-G3 domain. Biochemistry. 2007 Aug 21;46(33):9541-50. Epub 2007 Jul 25. PMID:17649979 doi:http://dx.doi.org/10.1021/bi7006383
- ↑ Porten E, Seliger B, Schneider VA, Woll S, Stangel D, Ramseger R, Kroger S. The process-inducing activity of transmembrane agrin requires follistatin-like domains. J Biol Chem. 2010 Jan 29;285(5):3114-25. doi: 10.1074/jbc.M109.039420. Epub 2009 , Nov 25. PMID:19940118 doi:http://dx.doi.org/10.1074/jbc.M109.039420
- ↑ Patel TR, Butler G, McFarlane A, Xie I, Overall CM, Stetefeld J. Site specific cleavage mediated by MMPs regulates function of agrin. PLoS One. 2012;7(9):e43669. doi: 10.1371/journal.pone.0043669. Epub 2012 Sep 11. PMID:22984437 doi:http://dx.doi.org/10.1371/journal.pone.0043669
- ↑ Gesemann M, Denzer AJ, Ruegg MA. Acetylcholine receptor-aggregating activity of agrin isoforms and mapping of the active site. J Cell Biol. 1995 Feb;128(4):625-36. PMID:7860635
- ↑ Bezakova G, Helm JP, Francolini M, Lomo T. Effects of purified recombinant neural and muscle agrin on skeletal muscle fibers in vivo. J Cell Biol. 2001 Jun 25;153(7):1441-52. PMID:11425874
- ↑ Baerwald-de la Torre K, Winzen U, Halfter W, Bixby JL. Glycosaminoglycan-dependent and -independent inhibition of neurite outgrowth by agrin. J Neurochem. 2004 Jul;90(1):50-61. PMID:15198666 doi:http://dx.doi.org/10.1111/j.1471-4159.2004.02454.x
- ↑ Scotton P, Bleckmann D, Stebler M, Sciandra F, Brancaccio A, Meier T, Stetefeld J, Ruegg MA. Activation of muscle-specific receptor tyrosine kinase and binding to dystroglycan are regulated by alternative mRNA splicing of agrin. J Biol Chem. 2006 Dec 1;281(48):36835-45. Epub 2006 Sep 29. PMID:17012237 doi:http://dx.doi.org/10.1074/jbc.M607887200
- ↑ Sallum CO, Kammerer RA, Alexandrescu AT. Thermodynamic and structural studies of carbohydrate binding by the agrin-G3 domain. Biochemistry. 2007 Aug 21;46(33):9541-50. Epub 2007 Jul 25. PMID:17649979 doi:http://dx.doi.org/10.1021/bi7006383
- ↑ Porten E, Seliger B, Schneider VA, Woll S, Stangel D, Ramseger R, Kroger S. The process-inducing activity of transmembrane agrin requires follistatin-like domains. J Biol Chem. 2010 Jan 29;285(5):3114-25. doi: 10.1074/jbc.M109.039420. Epub 2009 , Nov 25. PMID:19940118 doi:http://dx.doi.org/10.1074/jbc.M109.039420
- ↑ Patel TR, Butler G, McFarlane A, Xie I, Overall CM, Stetefeld J. Site specific cleavage mediated by MMPs regulates function of agrin. PLoS One. 2012;7(9):e43669. doi: 10.1371/journal.pone.0043669. Epub 2012 Sep 11. PMID:22984437 doi:http://dx.doi.org/10.1371/journal.pone.0043669
- ↑ Gesemann M, Denzer AJ, Ruegg MA. Acetylcholine receptor-aggregating activity of agrin isoforms and mapping of the active site. J Cell Biol. 1995 Feb;128(4):625-36. PMID:7860635
- ↑ Bezakova G, Helm JP, Francolini M, Lomo T. Effects of purified recombinant neural and muscle agrin on skeletal muscle fibers in vivo. J Cell Biol. 2001 Jun 25;153(7):1441-52. PMID:11425874
- ↑ Baerwald-de la Torre K, Winzen U, Halfter W, Bixby JL. Glycosaminoglycan-dependent and -independent inhibition of neurite outgrowth by agrin. J Neurochem. 2004 Jul;90(1):50-61. PMID:15198666 doi:http://dx.doi.org/10.1111/j.1471-4159.2004.02454.x
- ↑ Scotton P, Bleckmann D, Stebler M, Sciandra F, Brancaccio A, Meier T, Stetefeld J, Ruegg MA. Activation of muscle-specific receptor tyrosine kinase and binding to dystroglycan are regulated by alternative mRNA splicing of agrin. J Biol Chem. 2006 Dec 1;281(48):36835-45. Epub 2006 Sep 29. PMID:17012237 doi:http://dx.doi.org/10.1074/jbc.M607887200
- ↑ Sallum CO, Kammerer RA, Alexandrescu AT. Thermodynamic and structural studies of carbohydrate binding by the agrin-G3 domain. Biochemistry. 2007 Aug 21;46(33):9541-50. Epub 2007 Jul 25. PMID:17649979 doi:http://dx.doi.org/10.1021/bi7006383
- ↑ Porten E, Seliger B, Schneider VA, Woll S, Stangel D, Ramseger R, Kroger S. The process-inducing activity of transmembrane agrin requires follistatin-like domains. J Biol Chem. 2010 Jan 29;285(5):3114-25. doi: 10.1074/jbc.M109.039420. Epub 2009 , Nov 25. PMID:19940118 doi:http://dx.doi.org/10.1074/jbc.M109.039420
- ↑ Patel TR, Butler G, McFarlane A, Xie I, Overall CM, Stetefeld J. Site specific cleavage mediated by MMPs regulates function of agrin. PLoS One. 2012;7(9):e43669. doi: 10.1371/journal.pone.0043669. Epub 2012 Sep 11. PMID:22984437 doi:http://dx.doi.org/10.1371/journal.pone.0043669
- ↑ Gesemann M, Denzer AJ, Ruegg MA. Acetylcholine receptor-aggregating activity of agrin isoforms and mapping of the active site. J Cell Biol. 1995 Feb;128(4):625-36. PMID:7860635
- ↑ Bezakova G, Helm JP, Francolini M, Lomo T. Effects of purified recombinant neural and muscle agrin on skeletal muscle fibers in vivo. J Cell Biol. 2001 Jun 25;153(7):1441-52. PMID:11425874
- ↑ Baerwald-de la Torre K, Winzen U, Halfter W, Bixby JL. Glycosaminoglycan-dependent and -independent inhibition of neurite outgrowth by agrin. J Neurochem. 2004 Jul;90(1):50-61. PMID:15198666 doi:http://dx.doi.org/10.1111/j.1471-4159.2004.02454.x
- ↑ Scotton P, Bleckmann D, Stebler M, Sciandra F, Brancaccio A, Meier T, Stetefeld J, Ruegg MA. Activation of muscle-specific receptor tyrosine kinase and binding to dystroglycan are regulated by alternative mRNA splicing of agrin. J Biol Chem. 2006 Dec 1;281(48):36835-45. Epub 2006 Sep 29. PMID:17012237 doi:http://dx.doi.org/10.1074/jbc.M607887200
- ↑ Sallum CO, Kammerer RA, Alexandrescu AT. Thermodynamic and structural studies of carbohydrate binding by the agrin-G3 domain. Biochemistry. 2007 Aug 21;46(33):9541-50. Epub 2007 Jul 25. PMID:17649979 doi:http://dx.doi.org/10.1021/bi7006383
- ↑ Porten E, Seliger B, Schneider VA, Woll S, Stangel D, Ramseger R, Kroger S. The process-inducing activity of transmembrane agrin requires follistatin-like domains. J Biol Chem. 2010 Jan 29;285(5):3114-25. doi: 10.1074/jbc.M109.039420. Epub 2009 , Nov 25. PMID:19940118 doi:http://dx.doi.org/10.1074/jbc.M109.039420
- ↑ Patel TR, Butler G, McFarlane A, Xie I, Overall CM, Stetefeld J. Site specific cleavage mediated by MMPs regulates function of agrin. PLoS One. 2012;7(9):e43669. doi: 10.1371/journal.pone.0043669. Epub 2012 Sep 11. PMID:22984437 doi:http://dx.doi.org/10.1371/journal.pone.0043669
- ↑ Gesemann M, Denzer AJ, Ruegg MA. Acetylcholine receptor-aggregating activity of agrin isoforms and mapping of the active site. J Cell Biol. 1995 Feb;128(4):625-36. PMID:7860635
- ↑ Bezakova G, Helm JP, Francolini M, Lomo T. Effects of purified recombinant neural and muscle agrin on skeletal muscle fibers in vivo. J Cell Biol. 2001 Jun 25;153(7):1441-52. PMID:11425874
- ↑ Baerwald-de la Torre K, Winzen U, Halfter W, Bixby JL. Glycosaminoglycan-dependent and -independent inhibition of neurite outgrowth by agrin. J Neurochem. 2004 Jul;90(1):50-61. PMID:15198666 doi:http://dx.doi.org/10.1111/j.1471-4159.2004.02454.x
- ↑ Scotton P, Bleckmann D, Stebler M, Sciandra F, Brancaccio A, Meier T, Stetefeld J, Ruegg MA. Activation of muscle-specific receptor tyrosine kinase and binding to dystroglycan are regulated by alternative mRNA splicing of agrin. J Biol Chem. 2006 Dec 1;281(48):36835-45. Epub 2006 Sep 29. PMID:17012237 doi:http://dx.doi.org/10.1074/jbc.M607887200
- ↑ Sallum CO, Kammerer RA, Alexandrescu AT. Thermodynamic and structural studies of carbohydrate binding by the agrin-G3 domain. Biochemistry. 2007 Aug 21;46(33):9541-50. Epub 2007 Jul 25. PMID:17649979 doi:http://dx.doi.org/10.1021/bi7006383
- ↑ Porten E, Seliger B, Schneider VA, Woll S, Stangel D, Ramseger R, Kroger S. The process-inducing activity of transmembrane agrin requires follistatin-like domains. J Biol Chem. 2010 Jan 29;285(5):3114-25. doi: 10.1074/jbc.M109.039420. Epub 2009 , Nov 25. PMID:19940118 doi:http://dx.doi.org/10.1074/jbc.M109.039420
- ↑ Patel TR, Butler G, McFarlane A, Xie I, Overall CM, Stetefeld J. Site specific cleavage mediated by MMPs regulates function of agrin. PLoS One. 2012;7(9):e43669. doi: 10.1371/journal.pone.0043669. Epub 2012 Sep 11. PMID:22984437 doi:http://dx.doi.org/10.1371/journal.pone.0043669
- ↑ Stetefeld J, Alexandrescu AT, Maciejewski MW, Jenny M, Rathgeb-Szabo K, Schulthess T, Landwehr R, Frank S, Ruegg MA, Kammerer RA. Modulation of agrin function by alternative splicing and Ca2+ binding. Structure. 2004 Mar;12(3):503-15. PMID:15016366 doi:http://dx.doi.org/10.1016/j.str.2004.02.001
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