Development of p97 AAA ATPase inhibitors
Tsui-Fen Chou1, Raymond J Deshaies
1Division of Biology, California Institute of Technology, Pasadena, CA, USA. tfchou@caltech.edu
Autophagy
|May 25, 2011
Summary
A new p97 inhibitor, DBeQ, rapidly blocks both ubiquitin-proteasome and autophagic degradation pathways, leading to cell death. Future research aims to develop targeted inhibitors for specific p97 functions.
Area of Science:
- Biochemistry
- Cell Biology
- Chemical Biology
Background:
- p97 (valosin-containing protein) is an essential ubiquitin-selective chaperone involved in multiple cellular processes.
- Genetic methods to study p97 have limitations due to slow depletion and secondary effects.
- Small molecule inhibitors offer a rapid and specific approach to investigate p97 function.
Purpose of the Study:
- To investigate the effects of a novel small molecule p97 inhibitor, DBeQ.
- To determine DBeQ's impact on protein degradation pathways and cell viability.
- To explore the potential of developing 'separation of function' p97 inhibitors.
Main Methods:
- Identification and characterization of the small molecule p97 inhibitor N(2),N(4)-dibenzylquinazoline-2,4-diamine (DBeQ).
- Assessment of DBeQ's effects on autophagic degradation (LC3-II) and proteasomal degradation of p97-dependent substrates.
- Evaluation of DBeQ's impact on cell death pathways.
Main Results:
- DBeQ rapidly inhibits both the ubiquitin-proteasome system (UPS) and autophagic degradation.
- DBeQ treatment leads to rapid cell death, distinct from conventional proteasome inhibitors.
- DBeQ affects both UPS and autophagy, highlighting its broad impact on p97-mediated processes.
Conclusions:
- DBeQ is a potent research tool for studying p97 biology due to its rapid and dual action on protein degradation pathways.
- Further investigation is needed to elucidate the precise mechanisms of DBeQ-induced cell death (autophagic vs. apoptotic).
- The development of 'separation of function' p97 inhibitors is a promising future direction for both mechanistic studies and therapeutic applications.
Related Concept Videos
01:30Inhibitors of Viral Protein Synthesis
Protein synthesis is indispensable for viral replication, as viruses lack the cellular machinery required for this process and must hijack the host's translational apparatus. In response, host cells deploy a critical innate immune defense involving interferons, specialized cytokines that play a central role in inhibiting viral propagation.Upon viral detection, infected cells release interferons that bind to receptors on adjacent uninfected cells, activating the JAK-STAT signaling pathway and...
01:19Inhibitors of Virion Maturation and Assembly
As part of their replication cycle, certain viruses synthesize long precursor proteins called polyproteins within infected host cells. In human immunodeficiency virus (HIV), two major polyproteins are produced: Gag and Gag-Pol. The Gag polyprotein supplies the structural components of the virus, while Gag-Pol includes essential viral enzymes such as reverse transcriptase, integrase, and protease. After synthesis, these polyproteins move to the host cell membrane, where they assemble into an...
01:31The Intrinsic Apoptotic Pathway
Internal cellular stress, such as cellular injury or hypoxia, triggers intrinsic apoptosis. The B-cell lymphoma 2 (Bcl-2) family of proteins are the primary regulators of the intrinsic apoptotic pathway. For example, during DNA damage, checkpoint proteins, such as Ataxia Telangiectasia Mutated (ATM protein) and Checkpoints Factor-2 (Chk2) proteins, are activated. These proteins phosphorylate p53 which further activates pro-apoptotic proteins, such as Bax, Bak, PUMA, and Noxa, and inhibits...
01:19Allosteric Proteins-ATCase
Binding sites linkages can regulate a protein's function. For example, enzyme activity is often regulated through a feedback mechanism where the end product of the biochemical process serves as an inhibitor.
Aspartate transcarbamoylase (ATCase) is a cytosolic enzyme that catalyzes the condensation of L-aspartate and carbamoyl phosphate to N-carbamoyl-L-aspartate. This reaction is the first step in pyrimidine biosynthesis. UTP and CTP, the end products of the pyrimidine synthesis pathway,...
Aspartate transcarbamoylase (ATCase) is a cytosolic enzyme that catalyzes the condensation of L-aspartate and carbamoyl phosphate to N-carbamoyl-L-aspartate. This reaction is the first step in pyrimidine biosynthesis. UTP and CTP, the end products of the pyrimidine synthesis pathway,...
01:22Antiviral Nucleoside Inhibitors
Antiviral Nucleoside InhibitorsAntiviral nucleoside inhibitors are structural analogs of natural nucleosides that interfere with viral DNA or RNA synthesis. These compounds selectively target viral polymerases due to their resemblance to host nucleosides, thereby disrupting viral genome replication.Mechanism of Acyclovir ActionAcyclovir is a guanosine analog with a three-carbon acyclic side chain. It selectively targets herpes simplex virus type 1 (HSV-1), herpes simplex virus type 2 (HSV-2),...
01:48ATP Synthase: Mechanism
In animals, the mitochondrial F1F0 ATP synthase is the key protein that synthesizes ATP molecules through a complex catalytic mechanism. While the nuclear genome encodes the majority of ATP synthase subunits, the mitochondrial genome encodes some of the enzyme's most critical components. The formation of this multi-subunit enzyme is a complex multi-step process regulated at the level of transcription, translation, and assembly. Defects in one or more of these steps can result in decreased ATP...