Functional analysis of an ADAMTS10 signal peptide mutation in Weill-Marchesani syndrome demonstrates a long-range effect on secretion of the full-length enzyme.
We report the identification and functional analysis of the first missense ADAMTS10 mutation (c.73G>A; p.Ala25Thr) causing recessive Weill-Marchesani syndrome (WMS). The Ala25 residue affected by the missense mutation is at the -1 position relative to the ADAMTS10 signal peptidase cleavage site. p.Ala25Thr substituted full-length ADAMTS10 showed consistent and significantly diminished secretion in both HEK293F and Cos-1 cells. However, a C-terminally truncated construct lacking the ancillary domain and containing only the signal peptide, the propeptide and the catalytic domain (p.Ala25Thr Pro-Cat) was efficiently secreted in both HEK293F cells and Cos-1 cells. Edman degradation of purified p.Ala25Thr Pro-Cat and p.Ala25Thr substituted full-length ADAMTS10 from HEK293F cells demonstrated correct signal peptide processing. Thus, the p.Ala25Thr substitution hinders secretion of full-length ADAMTS10, but not Pro-Cat from cells, yet permits signal peptide removal. We infer that folding of the complex C-terminal ancillary domain is the rate-limiting step in biosynthesis of ADAMTS10, and that it (but not Pro-Cat) is sensitive to subtle changes in efficiency of signal peptide cleavage. These observations represent an unprecedented effect of a signal peptide mutation and support a model in which the initial cotranslational processing events during protein biosynthesis can have long-range effects on protein folding and secretion.
Department of Biomedical Engineering and Orthopaedic Research Center, Lerner Research Institute, Cleveland Clinic, Cleveland, Ohio 44195, USA.
Wendy E
WE
Kutz
Lauren W
LW
Wang
Nathalie
N
Dagoneau
Kazimir J
KJ
Odrcic
Valerie
V
Cormier-Daire
Elias I
EI
Traboulsi
Suneel S
SS
Apte
D051722:ADAM Proteins / Q000737:chemistry / Q000235:genetics*; D000071096:ADAMTS Proteins; D000369:Aged, 80 and over; D000818:Animals; D019556:COS Cells; D002460:Cell Line; D002522:Chlorocebus aethiops; D004252:DNA Mutational Analysis; D006130:Growth Disorders / Q000235:genetics*; D006801:Humans; D009154:Mutation; D021382:Protein Sorting Signals; D017434:Protein Structure, Tertiary; D013577:Syndrome
D021382:Protein Sorting Signals; D051722:ADAM Proteins; D000071096:ADAMTS Proteins; C494614:ADAMTS10 protein, human