PXD066622

PXD066622 is an original dataset announced via ProteomeXchange.

Title	Single molecule dynamics of the TRiC chaperonin system in vivo
Description	The essential chaperonin TRiC/CCT mediates protein folding in cooperation with the co-chaperone prefoldin (PFD). As shown in vitro, the cylindrical TRiC complex facilitates folding through ATP-regulated client protein encapsulation. However, the functional dynamics of the chaperonin system in vivo remain unexplored. Here, we developed single-particle tracking in human cells to monitor the interactions of TRiC/PFD with newly synthesized proteins. Both chaperones engaged nascent polypeptides repeatedly in brief probing events, typically lasting around one second, with PFD recruiting TRiC. As shown with the chaperonin client actin, the co-translational interactions of PFD and TRiC increased in frequency and lifetime during chain elongation. Close to translation termination, PFD bound for several seconds, facilitating TRiC recruitment for post-translational folding involving multiple reaction cycles of ~2.5 s. Notably, the lifetimes of TRiC interactions with a folding-defective actin mutant were markedly prolonged, indicating that client conformational properties modulate TRiC function. Mutant actin continued cycling on TRiC until targeted for degradation. Surprisingly, TRiC often remained confined near its client protein between successive binding cycles, suggesting that the chaperonin machinery operates within a localized ‘protective zone’ where free diffusion is restricted. Together, these findings offer detailed insight into the single-molecule dynamics and supramolecular organization of the chaperonin system in the cellular environment.
HostingRepository	PRIDE
AnnounceDate	2025-11-26
AnnouncementXML	Submission_2025-11-26_10:14:46.447.xml
DigitalObjectIdentifier
ReviewLevel	Peer-reviewed dataset
DatasetOrigin	Original dataset
RepositorySupport	Unsupported dataset by repository
PrimarySubmitter	Barbara Steigenberger
SpeciesList	scientific name: Homo sapiens (Human); NCBI TaxID: NEWT:9606;
ModificationList	No PTMs are included in the dataset
Instrument	Q Exactive HF; Orbitrap Exploris 480

Revision	Datetime	Status	ChangeLog Entry
0	2025-07-27 11:06:28	ID requested
⏵ 1	2025-11-26 10:14:46	announced

Dataset with its publication pending

submitter keyword: None

F. Ulrich
contact affiliation	Department of Cellular Biochemistry, Max Planck Institute of Biochemistry, Martinsried, Germany
contact email	uhartl@biochem.mpg.de
lab head
Barbara Steigenberger
contact affiliation	MPI of Biochemistry
contact email	steigenberger@biochem.mpg.de
dataset submitter

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PRIDE project URI

• PRIDE
  1. PXD066622
     1. Label: PRIDE project
     2. Name: Single molecule dynamics of the TRiC chaperonin system in vivo