Equivalent Mutations in the Eight Subunits of the Chaperonin CCT Produce Dramatically Different Cellular and Gene Expression Phenotypes
Date
2010-08-20Author
Amit, M
Weisberg, SJ
Nadler-Holly, M
McCormack, EA
Feldmesser, E
Kaganovich, D
Willison, KR
Horovitz, A
Type
Journal Article
Metadata
Show full item recordAbstract
The eukaryotic cytoplasmic chaperonin-containing TCP-1 (CCT) is a complex formed by two back-to-back stacked hetero-octameric rings that assists the folding of actins, tubulins, and other proteins in an ATP-dependent manner. Here, we tested the significance of the hetero-oligomeric nature of CCT in its function by introducing, in each of the eight subunits in turn, an identical mutation at a position that is conserved in all the subunits and is involved in ATP hydrolysis, in order to establish the extent of ‘individuality’ of the various subunits. Our results show that these identical mutations lead to dramatically different phenotypes. For example, Saccharomyces cerevisiae yeast cells with the mutation in subunit CCT2 display heat sensitivity and cold sensitivity for growth, have an excess of actin patches, and are the only strain here generated that is pseudo-diploid. By contrast, cells with the mutation in subunit CCT7 are the only ones to accumulate juxtanuclear protein aggregates that may reflect an impaired stress response in this strain. System-level analysis of the strains using RNA microarrays reveals connections between CCT and several cellular networks, including ribosome biogenesis and TOR2, that help to explain the phenotypic variability observed. (C) 2010 Elsevier Ltd. All rights reserved.
Collections
Research team
Chromatin Regulation
Wigley Group
Language
eng
License start date
2010-08-20
Citation
JOURNAL OF MOLECULAR BIOLOGY, 2010, 401 pp. 532 - 543
Publisher
ACADEMIC PRESS LTD- ELSEVIER SCIENCE LTD