|1kcq, resolution 1.65Å ()|
Human Gelsolin Domain 2 with a Cd2+ bound
Mutations in domain 2 (D2, residues 151-266) of the actin-binding protein gelsolin cause familial amyloidosis-Finnish type (FAF). These mutations, D187N or D187Y, lead to abnormal proteolysis of plasma gelsolin at residues 172-173 and a second hydrolysis at residue 243, resulting in an amyloidogenic fragment. Here we present the structure of human gelsolin D2 at 1.65 A and find that Asp 187 is part of a Cd2+ metal-binding site. Two Ca2+ ions are required for a conformational transition of gelsolin to its active form. Differential scanning calorimetry (DSC) and molecular dynamics (MD) simulations suggest that the Cd2+-binding site in D2 is one of these two Ca2+-binding sites and is essential to the stability of D2. Mutation of Asp 187 to Asn disrupts Ca2+ binding in D2, leading to instabilities upon Ca2+ activation. These instabilities make the domain a target for aberrant proteolysis, thereby enacting the first step in the cascade leading to FAF.
Loss of a metal-binding site in gelsolin leads to familial amyloidosis-Finnish type., Kazmirski SL, Isaacson RL, An C, Buckle A, Johnson CM, Daggett V, Fersht AR, Nat Struct Biol. 2002 Feb;9(2):112-6. PMID:11753432
From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine.
[GELS_HUMAN] Defects in GSN are the cause of amyloidosis type 5 (AMYL5) [MIM:105120]; also known as familial amyloidosis Finnish type. AMYL5 is a hereditary generalized amyloidosis due to gelsolin amyloid deposition. It is typically characterized by cranial neuropathy and lattice corneal dystrophy. Most patients have modest involvement of internal organs, but severe systemic disease can develop in some individuals causing peripheral polyneuropathy, amyloid cardiomyopathy, and nephrotic syndrome leading to renal failure.
[GELS_HUMAN] Calcium-regulated, actin-modulating protein that binds to the plus (or barbed) ends of actin monomers or filaments, preventing monomer exchange (end-blocking or capping). It can promote the assembly of monomers into filaments (nucleation) as well as sever filaments already formed. Plays a role in ciliogenesis.
About this Structure
- Kazmirski SL, Isaacson RL, An C, Buckle A, Johnson CM, Daggett V, Fersht AR. Loss of a metal-binding site in gelsolin leads to familial amyloidosis-Finnish type. Nat Struct Biol. 2002 Feb;9(2):112-6. PMID:11753432 doi:http://dx.doi.org/10.1038/nsb745
- ↑ Haltia M, Prelli F, Ghiso J, Kiuru S, Somer H, Palo J, Frangione B. Amyloid protein in familial amyloidosis (Finnish type) is homologous to gelsolin, an actin-binding protein. Biochem Biophys Res Commun. 1990 Mar 30;167(3):927-32. PMID:2157434
- ↑ Maury CP, Alli K, Baumann M. Finnish hereditary amyloidosis. Amino acid sequence homology between the amyloid fibril protein and human plasma gelsoline. FEBS Lett. 1990 Jan 15;260(1):85-7. PMID:2153578
- ↑ Ghiso J, Haltia M, Prelli F, Novello J, Frangione B. Gelsolin variant (Asn-187) in familial amyloidosis, Finnish type. Biochem J. 1990 Dec 15;272(3):827-30. PMID:2176481
- ↑ de la Chapelle A, Tolvanen R, Boysen G, Santavy J, Bleeker-Wagemakers L, Maury CP, Kere J. Gelsolin-derived familial amyloidosis caused by asparagine or tyrosine substitution for aspartic acid at residue 187. Nat Genet. 1992 Oct;2(2):157-60. PMID:1338910 doi:http://dx.doi.org/10.1038/ng1092-157
- ↑ Kim J, Lee JE, Heynen-Genel S, Suyama E, Ono K, Lee K, Ideker T, Aza-Blanc P, Gleeson JG. Functional genomic screen for modulators of ciliogenesis and cilium length. Nature. 2010 Apr 15;464(7291):1048-51. doi: 10.1038/nature08895. PMID:20393563 doi:10.1038/nature08895