Funding Organization(s): Karolinska Institutet, Center for Biosciences, Swedish Research Council, Gustafsson Foundation for Research in Natural Sciences and Medicine, Sven and Ebba-Christina Hagberg foundation, European Molecular Biology Organization, European Union
Primary Citation of Related Structures:   4WRN, 5BUP
PubMed Abstract: 
Uromodulin (UMOD)/Tamm-Horsfall protein, the most abundant human urinary protein, plays a key role in chronic kidney diseases and is a promising therapeutic target for hypertension. Via its bipartite zona pellucida module (ZP-N/ZP-C), UMOD forms extracellular filaments that regulate kidney electrolyte balance and innate immunity, as well as protect against renal stones ...
Uromodulin (UMOD)/Tamm-Horsfall protein, the most abundant human urinary protein, plays a key role in chronic kidney diseases and is a promising therapeutic target for hypertension. Via its bipartite zona pellucida module (ZP-N/ZP-C), UMOD forms extracellular filaments that regulate kidney electrolyte balance and innate immunity, as well as protect against renal stones. Moreover, salt-dependent aggregation of UMOD filaments in the urine generates a soluble molecular net that captures uropathogenic bacteria and facilitates their clearance. Despite the functional importance of its homopolymers, no structural information is available on UMOD and how it self-assembles into filaments. Here, we report the crystal structures of polymerization regions of human UMOD and mouse ZP2, an essential sperm receptor protein that is structurally related to UMOD but forms heteropolymers. The structure of UMOD reveals that an extensive hydrophobic interface mediates ZP-N domain homodimerization. This arrangement is required for filament formation and is directed by an ordered ZP-N/ZP-C linker that is not observed in ZP2 but is conserved in the sequence of deafness/Crohn's disease-associated homopolymeric glycoproteins α-tectorin (TECTA) and glycoprotein 2 (GP2). Our data provide an example of how interdomain linker plasticity can modulate the function of structurally similar multidomain proteins. Moreover, the architecture of UMOD rationalizes numerous pathogenic mutations in both UMOD and TECTA genes.
Related Citations: 
Characterization and separation of an inhibitor of viral hemagglutination present in urine. Tamm, I., Horsfall, F.L. (1950) Proc Soc Exp Biol Med 74: 106
Isolation of the cDNA encoding glycoprotein-2 (GP-2), the major zymogen granule membrane protein. Homology to uromodulin/Tamm-Horsfall protein. Hoops, T.C., Rindler, M.J. (1991) J Biol Chem 266: 4257
Mutations in the human alpha-tectorin gene cause autosomal dominant non-syndromic hearing impairment. Verhoeven, K., Van Laer, L., Kirschhofer, K., Legan, P.K., Hughes, D.C., Schatteman, I., Verstreken, M., Van Hauwe, P., Coucke, P., Chen, A., Smith, R.J., Somers, T., Offeciers, F.E., Van de Heyning, P., Richardson, G.P., Wachtler, F., Kimberling, W.J., Willems, P.J., Govaerts, P.J., Van Camp, G. (1998) Nat Genet 19: 60
The ZP domain is a conserved module for polymerization of extracellular proteins. Jovine, L., Qi, H., Williams, Z., Litscher, E., Wassarman, P.M. (2002) Nat Cell Biol 4: 457
Tamm-Horsfall glycoprotein: biology and clinical relevance. Serafini-Cessi, F., Malagolini, N., Cavallone, D. (2003) Am J Kidney Dis 42: 658
A duplicated motif controls assembly of zona pellucida domain proteins. Jovine, L., Qi, H., Williams, Z., Litscher, E.S., Wassarman, P.M. (2004) Proc Natl Acad Sci U S A 101: 5922
Zona pellucida domain proteins. Jovine, L., Darie, C.C., Litscher, E.S., Wassarman, P.M. (2005) Annu Rev Biochem 74: 83
Insights into egg coat assembly and egg-sperm interaction from the X-ray structure of full-length ZP3. Han, L., Monne, M., Okumura, H., Schwend, T., Cherry, A.L., Flot, D., Matsuda, T., Jovine, L. (2010) Cell 143: 404
The rediscovery of uromodulin (Tamm-Horsfall protein): from tubulointerstitial nephropathy to chronic kidney disease. Rampoldi, L., Scolari, F., Amoroso, A., Ghiggeri, G., Devuyst, O. (2011) Kidney Int 80: 338
Organizational Affiliation: 
Department of Biosciences and Nutrition & Center for Innovative Medicine, Karolinska Institutet, SE-141 83 Huddinge, Sweden; luca.jovine@ki.se.