Ubiquitin’s Pup(py)?

Science Signaling  18 Nov 2008:
Vol. 1, Issue 46, pp. ec399
DOI: 10.1126/scisignal.146ec399

Ubiquitin is a universal modifier used by eukaryotes to tag proteins for degradation. Now Pearce et al. (see the Perspective by Mukherjee and Orth) describe a ubiquitin-like protein system they call Pup in prokaryotes. Pup appears to be required for protein degradation by the Mycobacterium tuberculosis (Mtb) proteasome. Because proteasome function is essential for the virulence of Mtb, the Pup conjugation pathway could potentially be targeted for the development of antituberculosis drugs.

M. J. Pearce, J. Mintseris, J. Ferreyra, S. P. Gygi, K. H. Darwin, Ubiquitin-like protein involved in the proteasome pathway of Mycobacterium tuberculosis. Science 322, 1104–1107 (2008). [Abstract] [Full Text]

S. Mukherjee, K. Orth, A protein pupylation paradigm. Science 322, 1062–1063 (2008). [Summary] [Full Text]