# Molecular Mechanisms of Programmed Necrosis Execution

> **NIH NIH R35** · UT SOUTHWESTERN MEDICAL CENTER · 2024 · $410,000

## Abstract

PROJECT SUMMARY
Necroptosis is a caspase-independent type of programmed necrosis. The activation of the
necroptosis signaling cascade is implicated in the pathogenesis of various human diseases,
including cancer, inflammatory bowel disease, liver injury, pancreatitis, neurodegenerative
disorders, and a diverse range of viral, bacterial, and fungal infections, including SARS-CoV-2.
The necroptosis signaling cascade is mediated by the sequential activation of RIPK1 and RIPK3
kinases downstream of pro-inflammatory ligands such as TNF or microbe-associated
molecules. MLKL is a pseudokinase that tetramerizes upon phosphorylation by RIPK3 to form
water-permeable pores that drive cell membrane rupture. This pore formation stage leads to the
necrotic phenotype of necroptosis. It is also a critical point of cell fate determination, as
necroptosis execution can be halted and reversed at the MLKL stage. The mechanisms
regulating MLKL activation and execution of this type of programmed necrosis are poorly
understood. Here, we will fill in the gaps of our understanding of the molecular mechanisms that
regulate MLKL activation, tetramerization, and execution of necroptotic cell death via
phosphorylation and ubiquitination. We aim to determine the mechanistic roles of the MLKL
post-translational modification events in promoting or suppressing MLKL tetramerization and
identify the enzymes regulating MLKL-driven necrotic cell death via these events. We also aim
to determine which structural factors are required downstream of MLKL to execute the
necroptotic cell death. Finally, to validate the roles of these enzymes and factors in mediating
necroptosis in vivo, we will test how their genetic knockouts affect sensitivity to Vaccinia virus
infection, contributing to the future development of strategies for enhancing host anti-viral
response. Overall, this project will significantly expand our understanding of the cellular
signaling mechanisms upstream and downstream of MLKL at the necroptosis execution stage
and pave the way for future anti-microbial therapies, as well as treatments for diseases that
involve necroptosis execution.

## Key facts

- **NIH application ID:** 10928092
- **Project number:** 5R35GM146861-03
- **Recipient organization:** UT SOUTHWESTERN MEDICAL CENTER
- **Principal Investigator:** Ayaz Najafov
- **Activity code:** R35 (R01, R21, SBIR, etc.)
- **Funding institute:** NIH
- **Fiscal year:** 2024
- **Award amount:** $410,000
- **Award type:** 5
- **Project period:** 2022-09-20 → 2027-07-31

## Primary source

NIH RePORTER: https://reporter.nih.gov/project-details/10928092

## Citation

> US National Institutes of Health, RePORTER application 10928092, Molecular Mechanisms of Programmed Necrosis Execution (5R35GM146861-03). Retrieved via AI Analytics 2026-05-25 from https://api.ai-analytics.org/grant/nih/10928092. Licensed CC0.

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