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Principal Investigator: Eric J Bennett
Organization: UNIVERSITY OF CALIFORNIA, SAN DIEGO
Fiscal Year: 2024
Award: $590,920
Funding agency: National Institute of General Medical Sciences
PROJECT SUMMARY
Errors associated with DNA replication, transcription, mRNA processing, and protein biogenesis result in the
continuous production of potentially toxic defective proteins. The error-prone nature of these essential processes
requires robust quality control (QC) systems to effectively triage and destroy defective translation products.
Protein quality control is an essential component within the larger protein homeostasis (proteostasis) system and
proteostasis dysfunction has been implicated in human aging-related pathologies. On one hand, elevated protein
QC function is needed to enable neoplastic cell proliferation in cells with high mutational burdens or chromosomal
abnormalities. Conversely, impaired proteostasis and defects in protein QC function result in the enhanced
production of misfolded and toxic aggregation prone proteins that typify many neurodegenerative disorders.
These observations suggest that developing molecular strategies to predictably alter QC function to either
enhance, or limit QC capacity as needed can improve aging-associated disorders and extend human healthspan.
However, there is a surprising and substantial gap in our understanding of not only how QC systems selectively
engage their substrates, but also how substrates evade detection during proteostasis dysfunction. To make
substantive progress toward the goal of leveraging QC systems to combat aging-associated disorders, it is
necessary to identify and characterize cellular and molecular mechanisms that enable detection and degradation
of diverse QC substrates. Recent research progress from my lab has identified a spatially restricted QC pathway
that acts on stalled and collided ribosomal complexes both before and after translation initiation to target
defective translation products for degradation and recycle ribosomal complexes. Further, we have developed a
systematic pipeline for biochemical, structural, and cellular interrogation of enigmatic but critical QC ubiquitin
ligases that have been implicated in targeting diverse substrates for degradation by unknown mechanisms. We
have focused our initial studies on the ubiquitin ligase HUWE1. Our recently described HUWE1 structure
represents the first full-length structure of a HECT-domain ligase. We have generated a unique and powerful set
of genome-edited cell lines and HUWE1 variants that have and will enable molecular dissection of HUWE1
function, HUWE1 substrate identification, and identification of cellular stress conditions that require HUWE1 for
cellular survival and proliferation. Research outcomes achieved by the proposed studies will mechanistically
determine how terminally stalled ribosomes are sensed and resolved and how ribosome-associated QC
pathways can be manipulated to alter proteostasis function. Further, we will establish mechanisms by which QC
ligases engage substrates under normal and stressed conditions. Successful completion of the proposed
research will provide substantial progress toward our long-term goal of combating aging-associated human
pathology through the development of molecular strategies to modify cellular responses to chronic proteotoxic
stress and improve cellular fitness following proteostasis insults.
Terms: <APF-1><ATP-Dependent Proteolysis Factor 1><Aberrant Chromosome><Abscission><Biochemical><Biogenesis><Cell Body><Cell Growth in Number><Cell Line><Cell Multiplication><Cell Proliferation><CellLine><Cells><Cellular Proliferation><Cellular Stress><Cellular Stress Response><Chromosomal Aberrations><Chromosomal Abnormalities><Chromosomal Alterations><Chromosome Aberrations><Chromosome Alterations><Chromosome Anomalies><Chromosome abnormality><Chronic><Complex><Cytogenetic Aberrations><Cytogenetic Abnormalities><DNA Replication><DNA Synthesis><DNA biosynthesis><Defect><Degenerative Neurologic Disorders><Detection><Development><Disease><Disorder><Dissection><Excision><Extirpation><Gene Transcription><Genetic Alteration><Genetic Change><Genetic Transcription><Genetic defect><Goals><HMG-20><Health><High Mobility Protein 20><Human><Human Pathology><Length><Length of Life><Ligase><Ligase Gene><Link><Longevity><Messenger RNA><Modern Man><Molecular><Mutation><Nature><Nervous System Degenerative Diseases><Nervous System Diseases><Nervous System Disorder><Neural Degenerative Diseases><Neural degenerative Disorders><Neurodegenerative Diseases><Neurodegenerative Disorders><Neurologic Degenerative Conditions><Neurologic Disorders><Neurologic Dysfunctions><Neurological Disorders><Origin of Life><Outcomes Research><Pathology><Pathway interactions><Persons><Prevalence><Process><Production><Proliferating><Proteins><Proteome><Quality Control><RNA Expression><Recycling><Removal><Research><Ribosomes><Strains Cell Lines><Stress><Structure><Surgical Removal><Synthetases><System><Toxic effect><Toxicities><Transcription><Translation Initiation><Translations><Triage><Tumor Cell><Ubiquitin><Ubiquitin Ligase Component Gene><Ubiquitin Ligase Gene><Variant><Variation><abnormal protein homeostasis><abnormal proteostasis><aging associated><aging related><cell stress><chromosomal defect><chromosome defect><combat><cultured cell line><defective proteostasis><degenerative diseases of motor and sensory neurons><degenerative neurological diseases><developmental><fitness><genome editing><genome mutation><genomic editing><health-span><healthspan><healthy life span><improved><mRNA><neoplastic cell><neurodegenerative illness><neurological disease><neurological dysfunction><pathway><protein homeostasis><protein homeostasis decline><protein homeostasis deficiency><protein homeostasis dysfunction><protein homeostasis failure><protein homeostasis loss><proteostasis><proteostasis decline><proteostasis defect><proteostasis deficiency><proteostasis dysfunction><proteostasis dysregulation><proteostasis failure><proteostasis impairment><proteostasis loss><proteotoxic><proteotoxicity><resection><response><translation><ubiquitin ligase>