ATP Dependent Rotational Motion of Group II Chaperonin Observed by X-ray Single Molecule Tracking

Sekiguchi, Hiroshi; Nakagawa, Ayumi; Moriya, Kazuki; Makabe, Koki; Ichiyanagi, Kouhei; Nozawa, Shiro; Sato, Tokushi; Adachi, Shin‐ichi; Kuwajima, Kunihiro; Yohda, Masafumi; Sasaki, Y.

doi:10.1371/journal.pone.0064176

Cited by 38 publications

(42 citation statements)

References 28 publications

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“…This observation has been corroborated by directly monitoring movements resulting from ATP binding of the thermosome by diffracted X-ray tracking. The phase associated with ATP binding was observed to finish within 1s after the freeing of caged nucleotide [68]. Substrate binding sites on the apical domain are still accessible in this transient state, though not to the extent of the fully open complex.…”

Section: Nucleotide Driven Conformational Cycle Of the Group II Chapementioning

confidence: 99%

The Mechanism and Function of Group II Chaperonins

Lopez

Dalton

Frydman

2015

Journal of Molecular Biology

163

169

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Protein folding in the cell requires the assistance of enzymes collectively called chaperones. Among these, the chaperonins are 1 MDa ring-shaped oligomeric complexes that bind unfolded polypeptides and promote their folding within an isolated chamber in an ATP-dependent manner. Group II chaperonins, found in archaea and eukaryotes, contain a built-in lid that opens and closes over the central chamber. In eukaryotes, the chaperonin TRiC/CCT is hetero-oligomeric, consisting of two stacked rings of eight paralogous subunits each. TRiC facilitates folding of approximately 10% of the eukaryotic proteome, including many cytoskeletal components and cell cycle regulators. Folding of many cellular substrates of TRiC cannot be assisted by any other chaperone. A complete structural and mechanistic understanding of this highly conserved and essential chaperonin remains elusive. However, recent work is beginning to shed light on key aspects of chaperonin function, and how their unique properties underlie their contribution to maintaining cellular proteostasis.

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Section: Nucleotide Driven Conformational Cycle Of the Group II Chapementioning

confidence: 99%

The Mechanism and Function of Group II Chaperonins

Lopez

Dalton

Frydman

2015

Journal of Molecular Biology

163

169

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“…However, the conformational change from the closed to the open conformation has not been studied in detail. Our previous study showed the reverse rotational motion in the ATP hydrolysis cycle [8]. Thus, we propose that ADP or Pi release triggers the clockwise rotational motion to unfasten the closed conformation.…”

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confidence: 64%

“…Schematic illustration of the detection of internal motions of group II chaperonins by DXT . Reproduced from .…”

Section: Resultsmentioning

confidence: 99%

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Characterization of group II chaperonins from an acidothermophilic archaeon Picrophilus torridus

et al. 2016

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Chaperonins are a type of molecular chaperone that assist in the folding of proteins. Group II chaperonins play an important role in the proteostasis in the cytosol of archaea and eukarya. In this study, we expressed, purified, and characterized group II chaperonins from an acidothermophilic archaeon Picrophilus torridus . Two genes exist for group II chaperonins, and both of the gene products assemble to form double‐ring complexes similar to other archaeal group II chaperonins. One of the Picrophilus chaperonins, Pto CPN α, was able to refold denatured GFP at 50 °C. As expected, Pto CPN α exhibited an ATP ‐dependent conformational change that is observed by the change in fluorescence and diffracted X‐ray tracking ( DXT ). In contrast, Pto CPN α lost its protein folding ability at moderate temperatures, becoming unable to interact with unfolded proteins. At lower temperatures, the release rate of the captured GFP from Pto CPN α was accelerated, and the affinity of denatured protein to Pto CPN α was weakened at the lower temperatures. Unexpectedly, in the DXT experiment, the fine motions were enhanced at the lower temperatures. Taken together, the results suggest that the fine tilting motions of the apical domain might correlate with the affinity of group II chaperonins for denatured proteins.

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“…University of Leeds, Leeds, United Kingdom, 2 Hebei Medical University, Shijiazhuang, China. Ca 2þ -activated Cl-channels (CaCCs) are an important group of ion channels with diverse physiological roles whose molecular identity long time remained enigmatic.…”

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confidence: 99%

BDNF Modulates Presynaptic Functions at a Central Synapse

Baydyuk

Sheng

et al. 2014

Biophysical Journal

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In excitable cells, ion channels are often challenged by rapid and repetitive stimuli. Ion channel responses to repetitive stimulation shape cellular behaviors by regulating the duration and termination of bursting action potentials. Therefore, we have investigated the regulation of voltage-gated potassium (Kv) channels under high frequency stimuli, with a particular focus on the canonical delayed rectifier Kv1.2. Previous reports have demonstrated a unique prepulse potentiation behavior that is observed in Kv1.2 channels expressed in mammalian cell lines. In this study, we demonstrate that this prepulse potentiation enables Kv1.2 channels to exhibit marked use-dependent activation, with trains of brief depolarizations causing dramatic increases in elicited current. This property arises from a stabilization of the channel open state in potentiated channels by~2.5 kcal/mol, reflecting a 28 5 1 mV leftward shift in activation V1/2 after channel potentiation, and a marked acceleration of channel activation. Importantly, Kv subunits can assemble into heteromeric channels, generating diversity of function and sensitivity to signaling mechanisms. We demonstrate that although other Kv1 channel types are not prone to the use-dependent activation observed for Kv1.2, this property is conferred to other Kv1 subunits when they co-assemble with Kv1.2 in heteromeric channels. Our observations suggest a unique role for Kv1.2 subunits as potential suppressive components of heteromeric Kv1 channels, and describe a novel mechanism of channel regulation that will influence channel activity during bursts of cellular electrical activity. These findings illustrate that the functional output of heteromeric Kv channels integrates the biophysical properties and signaling sensitivities of their component subunits. We highlight the importance of expanding biophysical studies of Kv channels to better understand interactions between different subunit types in heteromeric complexes.

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ATP Dependent Rotational Motion of Group II Chaperonin Observed by X-ray Single Molecule Tracking

Cited by 38 publications

References 28 publications

The Mechanism and Function of Group II Chaperonins

The Mechanism and Function of Group II Chaperonins

Characterization of group II chaperonins from an acidothermophilic archaeon Picrophilus torridus

BDNF Modulates Presynaptic Functions at a Central Synapse

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