title: Post-liberation cleavage of signal peptides is catalyzed by the site-2 protease (S2P) in bacteria.
abstract: A signal peptide (SP) is cleaved off from presecretory proteins by signal peptidase during or immediately after insertion into the membrane. In metazoan cells, the cleaved SP then receives proteolysis by signal peptide peptidase, an intramembrane-cleaving protease (I-CLiP). However, bacteria lack any signal peptide peptidase member I-CLiP, and little is known about the metabolic fate of bacterial SPs. Here we show that Escherichia coli RseP, an site-2 protease (S2P) family I-CLiP, introduces a cleavage into SPs after their signal peptidase-mediated liberation from preproteins. A Bacillus subtilis S2P protease, RasP, is also shown to be involved in SP cleavage. These results uncover a physiological role of bacterial S2P proteases and update the basic knowledge about the fate of signal peptides in bacterial cells.
authors.affiliation: Institute for Virus Research, Kyoto University, Kyoto 606-8507, Japan.
authors.forename: Akira
authors.initials: A
authors.lastname: Saito
authors.forename: Yohei
authors.initials: Y
authors.lastname: Hizukuri
authors.forename: Ei-ichi
authors.initials: E
authors.lastname: Matsuo
authors.forename: Shinobu
authors.initials: S
authors.lastname: Chiba
authors.forename: Hiroyuki
authors.initials: H
authors.lastname: Mori
authors.forename: Osamu
authors.initials: O
authors.lastname: Nishimura
authors.forename: Koreaki
authors.initials: K
authors.lastname: Ito
authors.forename: Yoshinori
authors.initials: Y
authors.lastname: Akiyama
mesh_terms: D001412:Bacillus subtilis / Q000201:enzymology*; D002384:Catalysis; D010450:Endopeptidases / Q000378:metabolism*; D004926:Escherichia coli / Q000201:enzymology*; D029968:Escherichia coli Proteins / Q000378:metabolism*; D006868:Hydrolysis; D008565:Membrane Proteins / Q000378:metabolism*; D021382:Protein Sorting Signals
chemical_list: D029968:Escherichia coli Proteins; D008565:Membrane Proteins; D021382:Protein Sorting Signals; D010450:Endopeptidases; C440001:RseP protein, E coli