TAT-RHIM: a more complex issue than expected.

Abstract

Murine cytomegalovirus protein M45 contains a RIP homotypic interaction motif (RHIM) that is sufficient to confer protection of infected cells against necroptotic cell death. Mechanistically, the N-terminal region of M45 drives rapid self-assembly into homo-oligomeric amyloid fibrils, and interacts with the endogenous RHIM domains of receptor-interacting serine/threonine protein kinases (RIPK) 1, RIPK3, Z-DNA-binding protein 1, and Toll/interleukin-1 receptor domain-containing adaptor-inducing interferon-β. Remarkably, all four aforementioned mammalian proteins harbouring such a RHIM domain are key components of inflammatory signalling and regulated cell death (RCD) processes. Immunogenic cell death by regulated necrosis causes extensive tissue damage in a wide range of diseases, including ischaemia reperfusion injury, myocardial infarction, sepsis, stroke, and solid organ transplantation. To harness the cell death suppression properties of M45 protein in a therapeutically usable manner, we developed a synthetic peptide encompassing only the RHIM domain of M45. To trigger delivery of RHIM into target cells, we fused the transactivator protein transduction domain of human immunodeficiency virus 1 to the N-terminus of the peptide. The fused peptide could efficiently penetrate eukaryotic cells, but unexpectedly it eradicated or destroyed all tested cancer cell lines and primary cells irrespective of species without further stimulus through a necrosis-like cell death. Typical inhibitors of different forms of RCD cannot impede this process, which appears to involve a direct disruption of biomembranes. Nevertheless, our finding has potential clinical relevance; reliable induction of a necrotic form of cell death distinct from all known forms of RCD may offer a novel therapeutic approach to combat resistant tumour cells.

• Authors: Benedikt Kolbrink, Theresa Riebeling, Nikolas K Teiwes, Claudia Steinem, Hubert Kalbacher, Ulrich Kunzendorf, Stefan Krautwald
• Journal: The Biochemical journal (Biochem J) Vol. 479 Issue 3 Pg. 259-272 (02 11 2022) ISSN: 1470-8728 [Electronic] England
• PMID: 35015082 (Publication Type: Journal Article, Research Support, Non-U.S. Gov't)
• Copyright: © 2022 The Author(s).

Chemical References

• Amyloid
• Gene Products, tat
• Recombinant Fusion Proteins
• Viral Proteins
• Ribonucleotide Reductases
• m45 protein, Mouse cytomegalovirus 1
• RIPK1 protein, human
• RIPK3 protein, human
• Receptor-Interacting Protein Serine-Threonine Kinases

Topics

• Amino Acid Sequence
• Amyloid (metabolism)
• Animals
• Gene Products, tat (chemistry, genetics, metabolism)
• HIV-1 (chemistry)
• HT29 Cells
• Humans
• Male
• Mice
• Mice, Inbred C57BL
• Mice, Knockout
• NIH 3T3 Cells
• Necroptosis (genetics)
• Protein Domains
• Receptor-Interacting Protein Serine-Threonine Kinases (metabolism)
• Recombinant Fusion Proteins (metabolism)
• Ribonucleotide Reductases (chemistry, genetics, metabolism)
• Signal Transduction (genetics)
• U937 Cells
• Viral Proteins (chemistry, genetics, metabolism)