Details

Autor(en) / Beteiligte

• Rinaldi, Teresa
• Hofmann, Line
• Gambadoro, Alessia
• Cossard, Raynald
• Livnat-Levanon, Nurit
• Glickman, Michael H
• Frontali, Laura
• Delahodde, Agnès
• Shaw, Janet

Titel

Dissection of the carboxyl-terminal domain of the proteasomal subunit Rpn11 in maintenance of mitochondrial structure and function

Ist Teil von

• Molecular biology of the cell, 2008-03, Vol.19 (3), p.1022-1031

Ort / Verlag

United States: American Society for Cell Biology

Erscheinungsjahr

2008

Quelle

MEDLINE

Beschreibungen/Notizen

• We have previously demonstrated that the C-terminal part of Rpn11, a deubiquitinating enzyme in the lid of the proteasome, is essential for maintaining a correct cell cycle and normal mitochondrial morphology and function. The two roles are apparently unlinked as the mitochondrial role is mapped to the Carboxy-terminus, whereas the catalytic deubiquitinating activity is found within the N-terminal region. The mitochondrial defects are observed in rpn11-m1 (originally termed mpr1-1), a mutation that generates Rpn11 lacking the last 31 amino acids. No mitochondrial phenotypes are recorded for mutations in the MPN+/JAMM motif. In the present study, we investigated the participation of the last 31 amino acids of the Rpn11 protein by analysis of intragenic revertants and site-specific mutants. We identified a putative alpha-helix necessary for the maintenance of a correct cell cycle and determined that a very short region at the C-terminus of Rpn11 is essential for the maintenance of tubular mitochondrial morphology. Furthermore, we show that expression of the C-terminal part of Rpn11 is able to complement in trans all of the rpn11-m1 mitochondrial phenotypes. Finally, we investigate the mechanisms by which Rpn11 controls the mitochondrial shape and show that Rpn11 may regulate the mitochondrial fission and tubulation processes.