9UNW

mouse PDCD5-TRiC complex

Summary for 9UNW

• Entry DOI: 10.2210/pdb9unw/pdb
• EMDB information: 64367
• Descriptor: T-complex protein 1 subunit alpha, T-complex protein 1 subunit beta, T-complex protein 1 subunit gamma, ... (9 entities in total)
• Functional Keywords: complex, cofactor, chaperone
• Biological source: Mus musculus (house mouse); More
• Total number of polymer chains: 9
• Total formula weight: 493120.61

Authors

Song, Q.Q.,Cong, Y. (deposition date: 2025-04-24, release date: 2026-03-25)

Primary citation

Wei, H.,Song, Q.,Wang, L.,Deng, Q.,Wu, B.,Chen, Y.,Han, T.,Guo, Y.,Li, Z.,Dong, F.,Ma, S.,Zhao, Q.,Shi, X.,Pan, C.,Jiang, W.,Liu, X.,Chen, Y.,Jiao, R.,Yuan, L.,Liu, C.,Guo, X.,Cong, Y.,Li, W.
PDCD5 promotes substrate release from the TRiC complex in cilia and flagella.
Mol.Cell, 86:376-392.e11, 2026

PubMed Abstract: Approximately 10% of eukaryotic proteins are folded by the TRiC/CCT complex (TCP1-ring complex, also called CCT for cytosolic chaperonin containing TCP1), and only open-state TRiC can bind with programmed cell death 5 (PDCD5). However, the physiological role of the PDCD5-TRiC interaction remains elusive. Here, we show that PDCD5 is required for flagellum biogenesis and ciliogenesis and present the PDCD5-TRiC structures in their open states at near-atomic resolution. Mechanically, we find that PDCD5 promotes substrates release by competing with PhLP2A to interact with TRiC, and the depletion of PDCD5 traps flagellum- and cilium-associated proteins within TRiC, finally leading to malformed flagella of spermatids and cilia in mouse ciliated cells. Moreover, we demonstrate that the function of PDCD5 in flagellum biogenesis and ciliogenesis depends on the interaction with TRiC by its C terminus. These findings identify PDCD5 as a TRiC regulator to promote a subset of proteins release.

PubMed: 41506263
DOI: 10.1016/j.molcel.2025.12.012

Experimental method

ELECTRON MICROSCOPY (3.55 Å)