Reversible modulation of SIRT1 activity in a mouse strain

Area of Science:

• Molecular Biology
• Genetics
• Biochemistry

Background:

• Sirtuin 1 (SIRT1) protein deacetylase has diverse biological roles, including aging, cancer, metabolism, neurodegeneration, and immunity.
• Existing literature on SIRT1 function contains contradictions, necessitating better tools for its study.

Purpose of the Study:

• To create a genetically modified mouse model allowing inducible control over SIRT1 activity.
• To facilitate the elucidation of SIRT1's causal roles in various biological processes and diseases.

Main Methods:

• Engineered a fusion protein by linking the estrogen receptor ligand-binding domain (ER) to the C terminus of SIRT1.
• Utilized 4-hydroxy-tamoxifen (4OHT) as a ligand to modulate the activity and stability of the SIRT1-ER fusion protein.
• Assessed changes in SIRT1-ER protein activity and abundance in cultured cells and in vivo tissues.

Main Results:

• Treatment with 4OHT resulted in a 4-5 fold increase in SIRT1-ER catalytic activity.
• 4OHT-induced activation was primarily attributed to a 2-4 fold increase in SIRT1-ER protein levels.
• The observed increase in protein abundance was reversible and due to 4OHT-mediated protein stabilization.

Conclusions:

• The developed inducible SIRT1-ER mouse model provides a valuable tool for studying SIRT1 function.
• The ability to reversibly modulate SIRT1 levels and activity aids in establishing causal links between SIRT1 and its associated biological processes and diseases.