title: Sequence-specific intramembrane proteolysis: identification of a recognition motif in rhomboid substrates.
abstract: Members of the widespread rhomboid family of intramembrane proteases cleave transmembrane domain (TMD) proteins to regulate processes as diverse as EGF receptor signaling, mitochondrial dynamics, and invasion by apicomplexan parasites. However, lack of information about their substrates means that the biological role of most rhomboids remains obscure. Knowledge of how rhomboids recognize their substrates would illuminate their mechanism and might also allow substrate prediction. Previous work has suggested that rhomboid substrates are specified by helical instability in their TMD. Here we demonstrate that rhomboids instead primarily recognize a specific sequence surrounding the cleavage site. This recognition motif is necessary for substrate cleavage, it determines the cleavage site, and it is more strictly required than TM helix-destabilizing residues. Our work demonstrates that intramembrane proteases can be sequence specific and that genome-wide substrate prediction based on their recognition motifs is feasible.
authors.affiliation: MRC Laboratory of Molecular Biology, Cambridge, UK.
authors.forename: Kvido
authors.initials: K
authors.lastname: Strisovsky
authors.forename: Hayley J
authors.initials: HJ
authors.lastname: Sharpe
authors.forename: Matthew
authors.initials: M
authors.lastname: Freeman
mesh_terms: D000595:Amino Acid Sequence; D000818:Animals; D001426:Bacterial Proteins / Q000235:genetics / Q000378:metabolism; D019556:COS Cells; D002522:Chlorocebus aethiops; D029721:Drosophila Proteins / Q000235:genetics / Q000378:metabolism; D004331:Drosophila melanogaster; D006868:Hydrolysis; D008565:Membrane Proteins / Q000235:genetics / Q000378:metabolism*; D008969:Molecular Sequence Data; D016297:Mutagenesis, Site-Directed; D011993:Recombinant Fusion Proteins / Q000235:genetics / Q000378:metabolism; D012697:Serine Endopeptidases / Q000235:genetics / Q000378:metabolism*; D013379:Substrate Specificity / Q000235:genetics*; D016211:Transforming Growth Factor alpha / Q000235:genetics / Q000378:metabolism
chemical_list: D001426:Bacterial Proteins; D029721:Drosophila Proteins; D008565:Membrane Proteins; D011993:Recombinant Fusion Proteins; D016211:Transforming Growth Factor alpha; C083730:grk protein, Drosophila; D012697:Serine Endopeptidases