TY - JOUR
T1 - The serine protease HtrA1 cleaves misfolded transforming growth factor β-induced protein (TGFBIp) and induces amyloid formation
AU - Poulsen, Ebbe Toftgaard
AU - Nielsen, Nadia Sukusu
AU - Scavenius, Carsten
AU - Mogensen, Emilie Hage
AU - Risør, Michael W
AU - Runager, Kasper
AU - Lukassen, Marie V
AU - Rasmussen, Casper B
AU - Christiansen, Gunna
AU - Richner, Mette
AU - Vorum, Henrik
AU - Enghild, Jan J
N1 - © 2019 Poulsen et al.
PY - 2019/8/2
Y1 - 2019/8/2
N2 - The serine protease high-temperature requirement protein A1 (HtrA1) is associated with protein-misfolding disorders such as Alzheimer's disease and transforming growth factor β-induced protein (TGFBIp)-linked corneal dystrophy. In this study, using several biochemical and biophysical approaches, including recombinant protein expression, LC-MS/MS and 2DE analyses, and thioflavin T (ThT) fluorescence assays for amyloid fibril detection, and FTIR assays, we investigated the role of HtrA1 both in normal TGFBIp turnover and in corneal amyloid formation. We show that HtrA1 can cleave WT TGFBIp but prefers amyloidogenic variants. Corneal TGFBIp is extensively processed in healthy people, resulting in C-terminal degradation products spanning the FAS1-4 domain of TGFBIp. We show here that HtrA1 cleaves the WT FAS1-4 domain only inefficiently, whereas the amyloidogenic FAS1-4 mutations transform this domain into a considerably better HTRA1 substrate. Moreover, HtrA1 cleavage of the mutant FAS1-4 domains generated peptides capable of forming
in vitro amyloid aggregates. Significantly, these peptides have been previously identified in amyloid deposits
in vivo, supporting the idea that HtrA1 is a causative agent for TGFBIp-associated amyloidosis in corneal dystrophy. In summary, our results indicate that TGFBIp is an HtrA1 substrate and that some mutations in the gene encoding TGFBIp cause aberrant HtrA1-mediated processing that results in amyloidogenesis in corneal dystrophies.
AB - The serine protease high-temperature requirement protein A1 (HtrA1) is associated with protein-misfolding disorders such as Alzheimer's disease and transforming growth factor β-induced protein (TGFBIp)-linked corneal dystrophy. In this study, using several biochemical and biophysical approaches, including recombinant protein expression, LC-MS/MS and 2DE analyses, and thioflavin T (ThT) fluorescence assays for amyloid fibril detection, and FTIR assays, we investigated the role of HtrA1 both in normal TGFBIp turnover and in corneal amyloid formation. We show that HtrA1 can cleave WT TGFBIp but prefers amyloidogenic variants. Corneal TGFBIp is extensively processed in healthy people, resulting in C-terminal degradation products spanning the FAS1-4 domain of TGFBIp. We show here that HtrA1 cleaves the WT FAS1-4 domain only inefficiently, whereas the amyloidogenic FAS1-4 mutations transform this domain into a considerably better HTRA1 substrate. Moreover, HtrA1 cleavage of the mutant FAS1-4 domains generated peptides capable of forming
in vitro amyloid aggregates. Significantly, these peptides have been previously identified in amyloid deposits
in vivo, supporting the idea that HtrA1 is a causative agent for TGFBIp-associated amyloidosis in corneal dystrophy. In summary, our results indicate that TGFBIp is an HtrA1 substrate and that some mutations in the gene encoding TGFBIp cause aberrant HtrA1-mediated processing that results in amyloidogenesis in corneal dystrophies.
UR - http://www.scopus.com/inward/record.url?scp=85070745851&partnerID=8YFLogxK
U2 - 10.1074/jbc.RA119.009050
DO - 10.1074/jbc.RA119.009050
M3 - Journal article
C2 - 31197037
SN - 1083-351X
VL - 294
SP - 11817
EP - 11828
JO - The Journal of Biological Chemistry
JF - The Journal of Biological Chemistry
IS - 31
ER -