Related Experiment Video
Updated: Feb 22, 2026
Evaluation of Substrate Ubiquitylation by E3 Ubiquitin-ligase in Mammalian Cell Lysates
Published on: May 10, 2022
14-3-3ζ binds the proteasome, limits proteolytic function and enhances sensitivity to proteasome inhibitors
1Department of Hematology and Medical Oncology, Emory University, Atlanta, USA.
Abstract:
14-3-3 proteins are a family of master regulators of intracellular signaling, yet their impact on proteasome function is unknown. We demonstrate that 14-3-3ζ binds the 11S proteasome activator, limiting proteasome assembly and cellular capacity for protein degradation. To define the functional impact of 14-3-3ζ proteasomal binding in myeloma cells, silencing and overexpression experiments are performed. We find that downregulation of 14-3-3ζ impairs myeloma cell growth and confers resistance to clinically used proteasome inhibitors. In a large cohort of newly diagnosed myeloma patients, elevated expression of 14-3-3ζ is associated with high risk myeloma genetic subtypes and worse prognosis overall. Our work demonstrates the important role of 14-3-3ζ in regulating proteasome function, myeloma cell growth and sensitivity to therapeutics, and suggests regulation of 14-3-3ζ as a new approach in myeloma therapy.
Insights
14-3-3ζ protein regulates proteasome assembly and function. Downregulating 14-3-3ζ impairs myeloma cell growth and suggests it as a therapeutic target for multiple myeloma.
Area of Science:
- Cell Biology
- Molecular Biology
- Cancer Research
Background:
- 14-3-3 proteins are key intracellular signaling regulators.
- Their role in proteasome function and multiple myeloma remains unclear.
Purpose of the Study:
- To investigate the impact of 14-3-3ζ on proteasome assembly and function.
- To determine the role of 14-3-3ζ in multiple myeloma cell growth and therapeutic response.
Main Methods:
- Demonstrated 14-3-3ζ binding to the 11S proteasome activator.
- Utilized silencing and overexpression experiments in myeloma cells.
- Analyzed patient data from a cohort of newly diagnosed myeloma patients.
Main Results:
- 14-3-3ζ binding limits proteasome assembly and protein degradation capacity.
- Downregulation of 14-3-3ζ inhibits myeloma cell proliferation.
- Reduced 14-3-3ζ confers resistance to proteasome inhibitors.
- Elevated 14-3-3ζ expression correlates with high-risk myeloma subtypes and poor prognosis.
Conclusions:
- 14-3-3ζ is a critical regulator of proteasome function in myeloma.
- Targeting 14-3-3ζ may offer a novel therapeutic strategy for multiple myeloma.
- 14-3-3ζ expression serves as a prognostic biomarker in myeloma.
Related Concept Videos
01:13The Proteasome
In this pathway, the target proteins are first tagged with small proteins called ubiquitin. This involves participation of a series of enzymes including— E1 (ubiquitin-activating enzyme), E2 (ubiquitin-conjugating enzyme), and E3...
02:18The Proteasome
In this pathway, the target proteins are first tagged with small proteins called ubiquitin. A series of enzymes carry out the ubiquitination of the target proteins - E1 (ubiquitin-activating enzyme), E2 (ubiquitin-conjugating enzyme), and E3...
02:18The Proteasome
01:17The Proteasome Structure
The proteasome is an...
02:58Regulated Protein Degradation
Protein degradation plays two important roles in the cells. It helps to protect cells from misfolded or damaged proteins before they lead to a...
01:19Allosteric Proteins-ATCase
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...