Publication Date:
2015-01-24
Description:
The 26S proteasome is a key player in eukaryotic protein quality control and in the regulation of numerous cellular processes. Here, we describe quantitative in situ structural studies of this highly dynamic molecular machine in intact hippocampal neurons. We used electron cryotomography with the Volta phase plate, which allowed high fidelity and nanometer precision localization of 26S proteasomes. We undertook a molecular census of single- and double-capped proteasomes and assessed the conformational states of individual complexes. Under the conditions of the experiment-that is, in the absence of proteotoxic stress-only 20% of the 26S proteasomes were engaged in substrate processing. The remainder was in the substrate-accepting ground state. These findings suggest that in the absence of stress, the capacity of the proteasome system is not fully used.〈br /〉〈span class="detail_caption"〉Notes: 〈/span〉Asano, Shoh -- Fukuda, Yoshiyuki -- Beck, Florian -- Aufderheide, Antje -- Forster, Friedrich -- Danev, Radostin -- Baumeister, Wolfgang -- New York, N.Y. -- Science. 2015 Jan 23;347(6220):439-42. doi: 10.1126/science.1261197.〈br /〉〈span class="detail_caption"〉Author address: 〈/span〉Department of Molecular Structural Biology, Max-Planck Institute of Biochemistry, 82152 Martinsried, Germany. ; Department of Molecular Structural Biology, Max-Planck Institute of Biochemistry, 82152 Martinsried, Germany. baumeist@biochem.mpg.de.〈br /〉〈span class="detail_caption"〉Record origin:〈/span〉 〈a href="http://www.ncbi.nlm.nih.gov/pubmed/25613890" target="_blank"〉PubMed〈/a〉
Keywords:
Animals
;
Cells, Cultured
;
Hippocampus/*cytology/enzymology
;
Neurons/*enzymology/*ultrastructure
;
Proteasome Endopeptidase Complex/*chemistry
;
Protein Conformation
;
Rats
;
Stress, Physiological
Print ISSN:
0036-8075
Electronic ISSN:
1095-9203
Topics:
Biology
,
Chemistry and Pharmacology
,
Computer Science
,
Medicine
,
Natural Sciences in General
,
Physics
