Activity of the mycobacterial proteasomal ATPase Mpa is reversibly regulated by pupylation.
Pupylation is a bacterial post-translational modification of target proteins on lysine residues with prokaryotic ubiquitin-like protein Pup. Pup-tagged substrates are recognized by a proteasome-interacting ATPase termed Mpa in Mycobacterium tuberculosis. Mpa unfolds pupylated substrates and threads them into the proteasome core particle for degradation. Interestingly, Mpa itself is also a pupylation target. Here, we show that the Pup ligase PafA predominantly produces monopupylated Mpa modified homogeneously on a single lysine residue within its C-terminal region. We demonstrate that this modification renders Mpa functionally inactive. Pupylated Mpa can no longer support Pup-mediated proteasomal degradation due to its inability to associate with the proteasome core. Mpa is further inactivated by rapid Pup- and ATPase-driven deoligomerization of the hexameric Mpa ring. We show that pupylation of Mpa is chemically and functionally reversible. Mpa regains its enzymatic activity upon depupylation by the depupylase Dop, affording a rapid and reversible activity control over Mpa function.
Institute of Molecular Biology and Biophysics, ETH Zurich, 8093 Zurich, Switzerland.
Cyrille L
CL
Delley
Frank
F
Striebel
Franziska M
FM
Heydenreich
Dennis
D
Özcelik
Eilika
E
Weber-Ban
D000251:Adenosine Triphosphatases / Q000235:genetics / Q000378:metabolism*; D000581:Amidohydrolases / Q000235:genetics / Q000378:metabolism; D001426:Bacterial Proteins / Q000235:genetics / Q000378:metabolism*; D009169:Mycobacterium tuberculosis / Q000201:enzymology* / Q000235:genetics; D046988:Proteasome Endopeptidase Complex / Q000235:genetics / Q000378:metabolism*; D017510:Protein Folding; D011499:Protein Processing, Post-Translational / Q000502:physiology*; D059748:Proteolysis; D014452:Ubiquitins / Q000235:genetics / Q000378:metabolism*; D037521:Virulence Factors / Q000235:genetics / Q000378:metabolism
D001426:Bacterial Proteins; C533288:Pup protein, Mycobacterium tuberculosis; D014452:Ubiquitins; D037521:Virulence Factors; D046988:Proteasome Endopeptidase Complex; D000581:Amidohydrolases; C556013:Dop protein, Mycobacterium tuberculosis; D000251:Adenosine Triphosphatases