ATP Binding Induces Large Conformational Changes in the Apical and Equatorial Domains of the Eukaryotic Chaperonin Containing TCP-1 Complex

Llorca, Óscar; Smyth, Martin G.; Marco, Sergio; Carrascosa, José L.; Willison, Keith R.; Valpuesta, José M.

doi:10.1074/jbc.273.17.10091

Cited by 57 publications

(45 citation statements)

References 36 publications

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“…2 Third, the conformations in the nucleotide-free state and the ADP-bound state are the same or very similar to each other. This is consistent with previous results of electron microscopy and small angle neutron scattering measurement showing that the binding of ADP does not induce a major change in structure among group II chaperonins (12)(13)(14)29). Melki et al (30) pointed out that there are large differences between ADPAlF 4 Ϫ -CCT, corresponding to the state of transition of ATP hydrolysis, and ADP-CCT in electron microscopic images and hydrodynamic properties.…”

Section: Model Of the Functional Cycle Of T Ks-1 ␣ Subunit Chaperonin-supporting

confidence: 81%

“…On the other hand, Llorca et al (11) showed that the binding of AMP-PNP to CCT results in the cavity being closed off by the helical protrusions of the apical domains. Also, they showed that ATP induces an asymmetric structure; one of the rings in the conformation is similar to that of the nucleotide-free CCT, whereas the other presents a more open conformation (12,13). Gutsche and colleagues (14) pointed out that the binding of ATP or AMP-PNP to the thermosome induces the closed conformation.…”

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confidence: 99%

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ATP Binding Is Critical for the Conformational Change from an Open to Closed State in Archaeal Group II Chaperonin

Iizuka

Yoshida

Shomura

et al. 2003

Journal of Biological Chemistry

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Group II chaperonins, found in archaea and in eukaryotic cytosol, do not have a co-chaperonin corresponding to GroES. Instead, it is suggested that the helical protrusion extending from the apical domain acts as a built-in lid for the central cavity and that the opening and closing of the lid is regulated by ATP binding and hydrolysis. However, details of this conformational change remain unclear. To investigate the conformational change associated with the ATP-driven cycle, we conducted protease sensitivity analyses and tryptophan fluorescence spectroscopy of ␣-chaperonin from a hyperthermophilic archaeum, Thermococcus strain KS-1. In the nucleotide-free or ADP-bound state, the chaperonin, especially in the helical protrusion region, was highly sensitive to proteases. Addition of ATP and ammonium sulfate induced the transition to the relatively protease-resistant form. The fluorescence intensity of the tryptophan residue introduced at the tip of the helical protrusion was enhanced by the presence of ATP or ammonium sulfate. We conclude that ATP binding induces the conformational change from the lid-open to lid-closed form in archaeal group II chaperonin.Chaperonins, one of the principal molecular chaperones, capture non-native proteins and promote folding in vivo and in vitro in an ATP-dependent manner. They form large cylindrical complexes composed of two stacked rings of 7-9 subunits, each about 60 kDa in size. There is a large cavity in the center of the complex, where unfolded proteins may be encapsulated and undergo productive folding (1, 2). Based on protein sequence similarity and structural features, chaperonins are grouped into two subfamilies (3, 4). Group I chaperonins are found in bacteria and eukaryotic organelles, mitochondria and chloroplasts. The Escherichia coli chaperonin, GroEL, is the most extensively characterized member of the chaperonins. GroEL facilitates protein folding with a cofactor termed GroES in an ATP-dependent manner. GroES has two functions; it acts as a lid to cap the cavity of GroEL, and then induces the release of bound substrate protein into the GroEL-GroES cavity where it can undergo folding (5).The group II chaperonins are found in archaea (as thermosome) and in the cytosol of eukaryotic cells (as CCT or TRiC). 1Group II chaperonins do not have a co-chaperonin corresponding to GroES. The crystal structure of the group II chaperonin from an acidothermophilic archaeum, Thermoplasma acidophilum, suggested that the function of GroES is replaced by long helical protrusions from the apical domain (6, 7). These protrusions are thought to function as a "built-in lid" for the central cavity. Presumably, ATP binding drives group II chaperonins from the lid-open, substrate binding conformation, into the lid-closed conformation, where substrate folds within the central cavity (6 -9). However, the exact relationship between the nucleotide-bound state and the conformation is still controversial in group II chaperonins. Szpikowska et al. (10) reported that CCT is more resistant to tryp...

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Section: Model Of the Functional Cycle Of T Ks-1 ␣ Subunit Chaperonin-supporting

confidence: 81%

mentioning

confidence: 99%

ATP Binding Is Critical for the Conformational Change from an Open to Closed State in Archaeal Group II Chaperonin

Iizuka

Yoshida

Shomura

et al. 2003

Journal of Biological Chemistry

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“…The functional cycle of group II chaperonins is therefore likely to be more different from that of group I chaperonins than previously supposed (27). A mechanistic difference between the two chaperonin types is also indicated by the recent electron microscopy study of Llorca et al (31), which revealed very extensive loosening of both intra-and inter-ring contacts between subunits in just one of the two CCT rings upon binding of ATP or the non-hydrolyzable analog, AMP-PNP. No equivalent opening out occurs in GroEL upon ATP binding, but rather, large movements about hinge regions in the intermediate domain result in the movements of substrate binding sites on the apical domain up and away from the central cavity (3).…”

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confidence: 69%

“…Availability of pure components will also be required for an electron microscopic study of K ϩ -ATP-induced CCT disassembly. From the report of Llorca et al (31), we know at present that ATP, like AMP-PNP, binding to CCT causes extensive opening out of subunits within one of the two chaperonin rings, but since these specimens were prepared in the absence of K ϩ ions, structural changes consequent to ATP hydrolysis and the presence of the additional disassembly factor(s) could not have been observed. An electron microscopic examination will be particularly informative also because some idea of the time scale of the disassembly process will be obtained.…”

Section: Atp-dependent Disassembly Of the Cct Chaperoninmentioning

confidence: 99%

“…6, lower panel) correlated well with the order of subunit disassembly determined experimentally, with CCT␥ extending the longest loop and CCT␤, the shortest. Since this loop is in a good position to contribute to intra-ring subunit interactions, and is near the hinge region about which a large conformation change occurs on ATP binding (31), its length could well be a determining factor in the ease with which subunits can exit the core chaperonin particle. It is also interesting to note that the two subunits with the longest loop sequences (␥ and ␣) would be disposed opposite to each other in the ring orientation proposed by Liou , and CCT␤ (lower band).…”

Section: Fig 4 Cct Atpase Is Kmentioning

confidence: 99%

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Disassembly of the Cytosolic Chaperonin in Mammalian Cell Extracts at Intracellular Levels of K+ and ATP

Roobol

Grantham²,

Whitaker³

et al. 1999

Journal of Biological Chemistry

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The eukaryotic, cytoplasmic chaperonin, CCT, is essential for the biogenesis of actin-and tubulin-based cytoskeletal structures. CCT purifies as a doubly toroidal particle containing two eight-membered rings of ϳ60-kDa ATPase subunits, each encoded by an essential and highly conserved gene. However, immunofluorescence detection with subunit-specific antibodies has indicated that in cells CCT subunits do not always colocalize. We report here that CCT ATPase activity is highly dependent on K ؉ ion concentration and that in cell extracts, at physiological levels of K ؉ and ATP, there is considerable dissociation of CCT to a smaller oligomeric structure and free subunits. This dissociation is consequent to ATP hydrolysis and is readily reversed on removal of ATP. The ranking order for ease with which subunits can exit the chaperonin particle correlates well with the length of a loop structure, identified by homology modeling, in the intermediate domain of CCT subunits. K ؉ -ATP-induced disassembly is not an intrinsic property of purified CCT over a 40-fold concentration range and requires the presence of additional factor(s) present in cell extracts.The chaperonins are a group of molecular chaperones characterized by their double-ringed structure of ϳ60-kDa ATPase subunits enclosing a central cavity (1). Within this "Anfinsen cage" (2), folding substrates may be sequestered and undergo alternating cycles of nucleotide-dependent binding and release until a structure committed to forming the native state is achieved. Our current knowledge of the structure and mechanism of action of chaperonins rests largely on numerous studies of the homo-oligomeric tetradecameric chaperonin GroEL and its cochaperonin, GroES (e.g. Refs. 3 and 4), which facilitate the correct folding of a range of Escherichia coli proteins (5). Together with other eubacterial chaperonins and eukaryotic homologues in mitochondria and chloroplasts, these constitute group I type chaperonins (6), originally defined on the basis of amino acid sequence homology. Each GroEL subunit comprises three domains; the equatorial domain containing the ATP binding pocket and most intra-ring and all inter-ring contacts, which is connected via the intermediate domain to the apical domain, which contains binding sites for unfolded proteins and GroES (7). Folding substrate binding, ATP binding, GroES binding, folding substrate release, and ATP hydrolysis by GroEL subunits is a highly co-ordinated sequence of events (8), and this, together with their forming the enclosed central folding cavity, is likely to make the double-toroidal structure formed by the GroEL subunits essential to most of the protein folding activities of this chaperonin in vivo (9). Quite recently, however, recombinant GroEL apical domain "minichaperones" proved to have molecular chaperone activities for a limited range of substrates in vitro (10). Moreover, the activity of these minichaperones in vivo suggests functionality in protein folding for single GroEL subunits (11). However, there is no evidence...

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Structure and Function of the Cytosolic Chaperonin CCT

Valpuesta¹,

Carrascosa²,

Willison³

2005

Protein Folding Handbook

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ATP Binding Induces Large Conformational Changes in the Apical and Equatorial Domains of the Eukaryotic Chaperonin Containing TCP-1 Complex

Cited by 57 publications

References 36 publications

ATP Binding Is Critical for the Conformational Change from an Open to Closed State in Archaeal Group II Chaperonin

ATP Binding Is Critical for the Conformational Change from an Open to Closed State in Archaeal Group II Chaperonin

Disassembly of the Cytosolic Chaperonin in Mammalian Cell Extracts at Intracellular Levels of K+ and ATP

Structure and Function of the Cytosolic Chaperonin CCT

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