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Farrell K, Auerbach A, Musaus M, Navabpour S, Liu C, Lin Y, Xie H, Jarome TJ. Phosphorylation of RPT6 Controls Its Ability to Bind DNA and Regulate Gene Expression in the Hippocampus of Male Rats during Memory Formation. J Neurosci 2024; 44:e1453232023. [PMID: 38124005 PMCID: PMC10860611 DOI: 10.1523/jneurosci.1453-23.2023] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/01/2023] [Revised: 10/31/2023] [Accepted: 11/29/2023] [Indexed: 12/23/2023] Open
Abstract
Memory formation requires coordinated control of gene expression, protein synthesis, and ubiquitin-proteasome system (UPS)-mediated protein degradation. The catalytic component of the UPS, the 26S proteasome, contains a 20S catalytic core surrounded by two 19S regulatory caps, and phosphorylation of the 19S cap regulatory subunit RPT6 at serine 120 (pRPT6-S120) has been widely implicated in controlling activity-dependent increases in proteasome activity. Recently, RPT6 was also shown to act outside the proteasome where it has a transcription factor-like role in the hippocampus during memory formation. However, little is known about the proteasome-independent function of "free" RPT6 in the brain or during memory formation and whether phosphorylation of S120 is required for this transcriptional control function. Here, we used RNA-sequencing along with novel genetic approaches and biochemical, molecular, and behavioral assays to test the hypothesis that pRPT6-S120 functions independently of the proteasome to bind DNA and regulate gene expression during memory formation. RNA-sequencing following siRNA-mediated knockdown of free RPT6 revealed 46 gene targets in the dorsal hippocampus of male rats following fear conditioning, where RPT6 was involved in transcriptional activation and repression. Through CRISPR-dCas9-mediated artificial placement of RPT6 at a target gene, we found that RPT6 DNA binding alone may be important for altering gene expression following learning. Further, CRISPR-dCas13-mediated conversion of S120 to glycine on RPT6 revealed that phosphorylation at S120 is necessary for RPT6 to bind DNA and properly regulate transcription during memory formation. Together, we reveal a novel function for phosphorylation of RPT6 in controlling gene transcription during memory formation.
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Affiliation(s)
- Kayla Farrell
- Departments of School of Animal Sciences, Virginia Polytechnic Institute and State University, Blacksburg 24060, Virginia
| | - Aubrey Auerbach
- Biological Sciences, Virginia Polytechnic Institute and State University, Blacksburg 24060, Virginia
| | - Madeline Musaus
- School of Neuroscience, Virginia Polytechnic Institute and State University, Blacksburg 24060, Virginia
| | - Shaghayegh Navabpour
- Translational Biology, Medicine, and Health Graduate Program, Virginia Polytechnic Institute and State University, Blacksburg 24060, Virginia
| | - Catherine Liu
- Departments of School of Animal Sciences, Virginia Polytechnic Institute and State University, Blacksburg 24060, Virginia
| | - Yu Lin
- Department of Biomedical Sciences and Pathobiology, Virginia-Maryland College of Veterinary Medicine, Blacksburg 24060, Virginia
| | - Hehuang Xie
- School of Neuroscience, Virginia Polytechnic Institute and State University, Blacksburg 24060, Virginia
- Department of Biomedical Sciences and Pathobiology, Virginia-Maryland College of Veterinary Medicine, Blacksburg 24060, Virginia
- Fralin Life Science Institute at Virginia Tech, Blacksburg 24060, Virginia
| | - Timothy J Jarome
- Departments of School of Animal Sciences, Virginia Polytechnic Institute and State University, Blacksburg 24060, Virginia
- School of Neuroscience, Virginia Polytechnic Institute and State University, Blacksburg 24060, Virginia
- Translational Biology, Medicine, and Health Graduate Program, Virginia Polytechnic Institute and State University, Blacksburg 24060, Virginia
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Patrick MB, Omar N, Werner CT, Mitra S, Jarome TJ. The ubiquitin-proteasome system and learning-dependent synaptic plasticity - A 10 year update. Neurosci Biobehav Rev 2023; 152:105280. [PMID: 37315660 DOI: 10.1016/j.neubiorev.2023.105280] [Citation(s) in RCA: 4] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/26/2023] [Revised: 05/22/2023] [Accepted: 06/08/2023] [Indexed: 06/16/2023]
Abstract
Over 25 years ago, a seminal paper demonstrated that the ubiquitin-proteasome system (UPS) was involved in activity-dependent synaptic plasticity. Interest in this topic began to expand around 2008 following another seminal paper showing that UPS-mediated protein degradation controlled the "destabilization" of memories following retrieval, though we remained with only a basic understanding of how the UPS regulated activity- and learning-dependent synaptic plasticity. However, over the last 10 years there has been an explosion of papers on this topic that has significantly changed our understanding of how ubiquitin-proteasome signaling regulates synaptic plasticity and memory formation. Importantly, we now know that the UPS controls much more than protein degradation, is involved in plasticity underlying drugs of abuse and that there are significant sex differences in how ubiquitin-proteasome signaling is used for memory storage processes. Here, we aim to provide a critical 10-year update on the role of ubiquitin-proteasome signaling in synaptic plasticity and memory formation, including updated cellular models of how ubiquitin-proteasome activity could be regulating learning-dependent synaptic plasticity in the brain.
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Affiliation(s)
- Morgan B Patrick
- School of Neuroscience, Virginia Polytechnic Institute and State University, Blacksburg, VA, USA
| | - Nour Omar
- School of Neuroscience, Virginia Polytechnic Institute and State University, Blacksburg, VA, USA
| | - Craig T Werner
- Department of Pharmacology and Physiology, Oklahoma State University Center for Health Sciences, Tulsa, OK, USA; National Center for Wellness and Recovery, Oklahoma State University Center for Health Sciences, Tulsa, OK, USA.
| | - Swarup Mitra
- Department of Biomedical Sciences, Joan C Edwards School of Medicine, Marshall University, Huntington, WV, USA.
| | - Timothy J Jarome
- School of Neuroscience, Virginia Polytechnic Institute and State University, Blacksburg, VA, USA; School of Animal Sciences, Virginia Polytechnic Institute and State University, Blacksburg, VA, USA.
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