Role of inorganic polyphosphate in promoting ribosomal protein degradation by the Lon protease in E. coli.
Inorganic polyphosphate (polyP), a polymer of hundreds of phosphate (Pi) residues, accumulates in Escherichia coli in response to stresses, including amino acid starvation. Here we show that the adenosine 5'-triphosphate-dependent protease Lon formed a complex with polyP and degraded most of the ribosomal proteins, including S2, L9, and L13. Purified S2 also bound to polyP and formed a complex with Lon in the presence of polyP. Thus, polyP may promote ribosomal protein degradation by the Lon protease, thereby supplying the amino acids needed to respond to starvation.
Kuroda
A
A
Department of Molecular Biotechnology, Graduate School of Advanced Sciences of Matter, Hiroshima University, 1-4-1 Kagamiyama, Hiroshima 739-8527, Japan. akuroda@hiroshima-u.ac.jp
Nomura
K
K
Ohtomo
R
R
Kato
J
J
Ikeda
T
T
Takiguchi
N
N
Ohtake
H
H
Kornberg
A
A
D049069:ATP-Dependent Proteases; D000222:Adaptation, Physiological; D000251:Adenosine Triphosphatases / Q000235:genetics / Q000378:metabolism; D000255:Adenosine Triphosphate / Q000378:metabolism; D000595:Amino Acid Sequence; D000596:Amino Acids / Q000378:metabolism; D001426:Bacterial Proteins / Q000737:chemistry / Q000378:metabolism*; D049071:Endopeptidase Clp; D004926:Escherichia coli / Q000235:genetics / Q000378:metabolism*; D029968:Escherichia coli Proteins; D006360:Heat-Shock Proteins / Q000235:genetics / Q000378:metabolism*; D008969:Molecular Sequence Data; D009154:Mutation; D017856:Phosphotransferases (Phosphate Group Acceptor) / Q000235:genetics / Q000378:metabolism; D011122:Polyphosphates / Q000378:metabolism*; D049070:Protease La; D012269:Ribosomal Proteins / Q000737:chemistry / Q000378:metabolism*; D012270:Ribosomes / Q000378:metabolism; D012697:Serine Endopeptidases / Q000235:genetics / Q000378:metabolism*
D000596:Amino Acids; D001426:Bacterial Proteins; D029968:Escherichia coli Proteins; D006360:Heat-Shock Proteins; D011122:Polyphosphates; D012269:Ribosomal Proteins; C049650:ribosomal protein L9; C030004:ribosomal protein S2; D000255:Adenosine Triphosphate; D017856:Phosphotransferases (Phosphate Group Acceptor); C022424:polyphosphate kinase; D049069:ATP-Dependent Proteases; D012697:Serine Endopeptidases; C483567:Lon protein, E coli; D049070:Protease La; D049071:Endopeptidase Clp; D000251:Adenosine Triphosphatases