5n47

Structural highlights

Disease

[FINC_HUMAN] Defects in FN1 are the cause of glomerulopathy with fibronectin deposits type 2 (GFND2) [MIM:601894]; also known as familial glomerular nephritis with fibronectin deposits or fibronectin glomerulopathy. GFND is a genetically heterogeneous autosomal dominant disorder characterized clinically by proteinuria, microscopic hematuria, and hypertension that leads to end-stage renal failure in the second to fifth decade of life.^[1]

Function

[NGAL_HUMAN] Iron-trafficking protein involved in multiple processes such as apoptosis, innate immunity and renal development. Binds iron through association with 2,5-dihydroxybenzoic acid (2,5-DHBA), a siderophore that shares structural similarities with bacterial enterobactin, and delivers or removes iron from the cell, depending on the context. Iron-bound form (holo-24p3) is internalized following binding to the SLC22A17 (24p3R) receptor, leading to release of iron and subsequent increase of intracellular iron concentration. In contrast, association of the iron-free form (apo-24p3) with the SLC22A17 (24p3R) receptor is followed by association with an intracellular siderophore, iron chelation and iron transfer to the extracellular medium, thereby reducing intracellular iron concentration. Involved in apoptosis due to interleukin-3 (IL3) deprivation: iron-loaded form increases intracellular iron concentration without promoting apoptosis, while iron-free form decreases intracellular iron levels, inducing expression of the proapoptotic protein BCL2L11/BIM, resulting in apoptosis. Involved in innate immunity, possibly by sequestrating iron, leading to limit bacterial growth.^[2] [FINC_HUMAN] Fibronectins bind cell surfaces and various compounds including collagen, fibrin, heparin, DNA, and actin. Fibronectins are involved in cell adhesion, cell motility, opsonization, wound healing, and maintenance of cell shape.^{[3] [4] [5] [6]} Anastellin binds fibronectin and induces fibril formation. This fibronectin polymer, named superfibronectin, exhibits enhanced adhesive properties. Both anastellin and superfibronectin inhibit tumor growth, angiogenesis and metastasis. Anastellin activates p38 MAPK and inhibits lysophospholipid signaling.^{[7] [8] [9] [10]}

References

1. ↑ Castelletti F, Donadelli R, Banterla F, Hildebrandt F, Zipfel PF, Bresin E, Otto E, Skerka C, Renieri A, Todeschini M, Caprioli J, Caruso RM, Artuso R, Remuzzi G, Noris M. Mutations in FN1 cause glomerulopathy with fibronectin deposits. Proc Natl Acad Sci U S A. 2008 Feb 19;105(7):2538-43. Epub 2008 Feb 11. PMID:18268355 doi:0707730105
2. ↑ Yang J, Goetz D, Li JY, Wang W, Mori K, Setlik D, Du T, Erdjument-Bromage H, Tempst P, Strong R, Barasch J. An iron delivery pathway mediated by a lipocalin. Mol Cell. 2002 Nov;10(5):1045-56. PMID:12453413
3. ↑ Morla A, Zhang Z, Ruoslahti E. Superfibronectin is a functionally distinct form of fibronectin. Nature. 1994 Jan 13;367(6459):193-6. PMID:8114919 doi:http://dx.doi.org/10.1038/367193a0
4. ↑ Yi M, Ruoslahti E. A fibronectin fragment inhibits tumor growth, angiogenesis, and metastasis. Proc Natl Acad Sci U S A. 2001 Jan 16;98(2):620-4. PMID:11209058 doi:10.1073/pnas.98.2.620
5. ↑ Ambesi A, Klein RM, Pumiglia KM, McKeown-Longo PJ. Anastellin, a fragment of the first type III repeat of fibronectin, inhibits extracellular signal-regulated kinase and causes G(1) arrest in human microvessel endothelial cells. Cancer Res. 2005 Jan 1;65(1):148-56. PMID:15665290
6. ↑ You R, Klein RM, Zheng M, McKeown-Longo PJ. Regulation of p38 MAP kinase by anastellin is independent of anastellin's effect on matrix fibronectin. Matrix Biol. 2009 Mar;28(2):101-9. doi: 10.1016/j.matbio.2009.01.003. Epub 2009, Feb 4. PMID:19379667 doi:10.1016/j.matbio.2009.01.003
7. ↑ Morla A, Zhang Z, Ruoslahti E. Superfibronectin is a functionally distinct form of fibronectin. Nature. 1994 Jan 13;367(6459):193-6. PMID:8114919 doi:http://dx.doi.org/10.1038/367193a0
8. ↑ Yi M, Ruoslahti E. A fibronectin fragment inhibits tumor growth, angiogenesis, and metastasis. Proc Natl Acad Sci U S A. 2001 Jan 16;98(2):620-4. PMID:11209058 doi:10.1073/pnas.98.2.620
9. ↑ Ambesi A, Klein RM, Pumiglia KM, McKeown-Longo PJ. Anastellin, a fragment of the first type III repeat of fibronectin, inhibits extracellular signal-regulated kinase and causes G(1) arrest in human microvessel endothelial cells. Cancer Res. 2005 Jan 1;65(1):148-56. PMID:15665290
10. ↑ You R, Klein RM, Zheng M, McKeown-Longo PJ. Regulation of p38 MAP kinase by anastellin is independent of anastellin's effect on matrix fibronectin. Matrix Biol. 2009 Mar;28(2):101-9. doi: 10.1016/j.matbio.2009.01.003. Epub 2009, Feb 4. PMID:19379667 doi:10.1016/j.matbio.2009.01.003
11. ↑ Schiefner A, Gebauer M, Richter A, Skerra A. Anticalins Reveal High Plasticity in the Mode of Complex Formation with a Common Tumor Antigen. Structure. 2018 Mar 5. pii: S0969-2126(18)30043-1. doi:, 10.1016/j.str.2018.02.003. PMID:29526433 doi:http://dx.doi.org/10.1016/j.str.2018.02.003