9llk
From Proteopedia
The cryo-EM structure of the heterododecameric human Derlin-1/p97 complex
Structural highlights
DiseaseTERA_HUMAN Defects in VCP are the cause of inclusion body myopathy with early-onset Paget disease and frontotemporal dementia (IBMPFD) [MIM:167320; also known as muscular dystrophy, limb-girdle, with Paget disease of bone or pagetoid amyotrophic lateral sclerosis or pagetoid neuroskeletal syndrome or lower motor neuron degeneration with Paget-like bone disease. IBMPFD features adult-onset proximal and distal muscle weakness (clinically resembling limb girdle muscular dystrophy), early-onset Paget disease of bone in most cases and premature frontotemporal dementia.[1] [2] [3] [4] [5] Defects in VCP are the cause of amyotrophic lateral sclerosis type 14 with or without frontotemporal dementia (ALS14) [MIM:613954. ALS14 is a neurodegenerative disorder affecting upper motor neurons in the brain and lower motor neurons in the brain stem and spinal cord, resulting in fatal paralysis. Sensory abnormalities are absent. The pathologic hallmarks of the disease include pallor of the corticospinal tract due to loss of motor neurons, presence of ubiquitin-positive inclusions within surviving motor neurons, and deposition of pathologic aggregates. The etiology of amyotrophic lateral sclerosis is likely to be multifactorial, involving both genetic and environmental factors. The disease is inherited in 5-10% of the cases. Patients with ALS14 may develop frontotemporal dementia.[6] FunctionTERA_HUMAN Necessary for the fragmentation of Golgi stacks during mitosis and for their reassembly after mitosis. Involved in the formation of the transitional endoplasmic reticulum (tER). The transfer of membranes from the endoplasmic reticulum to the Golgi apparatus occurs via 50-70 nm transition vesicles which derive from part-rough, part-smooth transitional elements of the endoplasmic reticulum (tER). Vesicle budding from the tER is an ATP-dependent process. The ternary complex containing UFD1L, VCP and NPLOC4 binds ubiquitinated proteins and is necessary for the export of misfolded proteins from the ER to the cytoplasm, where they are degraded by the proteasome. The NPLOC4-UFD1L-VCP complex regulates spindle disassembly at the end of mitosis and is necessary for the formation of a closed nuclear envelope. Regulates E3 ubiquitin-protein ligase activity of RNF19A (By similarity). Component of the VCP/p97-AMFR/gp78 complex that participates in the final step of the sterol-mediated ubiquitination and endoplasmic reticulum-associated degradation (ERAD) of HMGCR. Also involved in DNA damage response: recruited to double-strand breaks (DSBs) sites in a RNF8- and RNF168-dependent manner and promotes the recruitment of TP53BP1 at DNA damage sites. Recruited to stalled replication forks by SPRTN: may act by mediating extraction of DNA polymerase eta (POLH) to prevent excessive translesion DNA synthesis and limit the incidence of mutations induced by DNA damage.[7] [8] [9] [10] [11] [12] [13] Publication Abstract from PubMedThe ER-associated degradation (ERAD) pathway retrotranslocates misfolded proteins from the ER lumen to the cytoplasm for proteasomal degradation. Derlin-1 and p97 are central to this process, forming a canonical 4:6 complex with tetrameric Derlin-1. Using cryo-electron microscopy, we identify a novel human Derlin-1/p97 complex with a 6:6 stoichiometry, where hexameric Derlin-1 assembles as three dimers. This hexameric channel forms a significantly larger trans-ER membrane tunnel, potentially accommodating bulkier substrates. Structural comparisons revealed conformational flexibility in Derlin-1, suggesting the "U"-shaped tetramer may act as an intermediate in hexamer formation. The formation of this hexameric channel is mediated by interactions with p97 and appears dependent on p97's ATPase activity, which provides the driving force for the transition between the tetrameric channel conformation to the intermediate "U"-shaped conformation. These findings highlight the dynamic nature of the Derlin-1/p97 complex and its implications for understanding ERAD retrotranslocation. Cryo-EM structure of the human Derlin-1/p97 complex reveals a hexameric channel in ERAD.,Wang Q, Yao D, Rao B, Xia Y, Li W, Li S, Cao M, Shen Y, Qin A, Cao Y Commun Biol. 2025 Oct 17;8(1):1481. doi: 10.1038/s42003-025-08880-5. PMID:41107410[14] From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine. References
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Categories: Homo sapiens | Large Structures | Cao Y | Li S | Li W | Rao B | Shen Y | Wang Q | Xia Y | Yao D
