7rlb | pdb_00007rlb
Cryo-EM structure of human p97-A232E mutant bound to ADP
Structural highlights
Disease[TERA_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] Function[TERA_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 human AAA ATPase p97, a potential target for cancer therapeutics, plays a vital role in the clearing of misfolded proteins. p97 dysfunction is also known to play a crucial role in several neurodegenerative disorders, such as MultiSystem Proteinopathy 1 (MSP-1) and Familial Amyotrophic Lateral Sclerosis (ALS). However, the structural basis of its role in such diseases remain elusive. Here, we present cryo-EM structural analyses of four disease mutants p97R155H, p97R191Q, p97A232E, p97D592N, as well as p97E470D, implicated in resistance to the drug CB-5083, a potent p97 inhibitor. Our cryo-EM structures demonstrate that these mutations affect nucleotide-driven allosteric activation across the three principal p97 domains (N, D1 and D2) by predominantly interfering with either 1) the coupling between the D1 and N-terminal domains (p97R155H and p97R191Q), 2) the inter-protomer interactions (p97A232E), or 3) the coupling between D1 and D2 nucleotide domains (p97D592N, p97E470D). We also show that binding of the competitive inhibitor, CB-5083, to the D2 domain prevents conformational changes similar to those seen for mutations that affect coupling between the D1 and D2 domains. Our studies enable tracing of the path of allosteric activation across p97 and establish a common mechanistic link between active site inhibition and defects in allosteric activation by disease-causing mutations, and have potential implications for the design of novel allosteric compounds that can modulate p97 function. Common mutations of AAA ATPase p97 and inhibitor binding disrupt inter-domain coupling and subsequent allosteric activation.,Caffrey B, Zhu X, Berezuk A, Tuttle K, Chittori S, Subramaniam S J Biol Chem. 2021 Sep 11:101187. doi: 10.1016/j.jbc.2021.101187. PMID:34520757[14] From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine. References
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