Why does SIRT1 go down in aging & senescence?

Why activate a protein if it isn't even there? In this video I discuss the recent paper; SIRT1 is downregulated by autophagy in senescence and ageing. (Xu, C., Wang, L., Fozouni, P. et al. SIRT1 is downregulated by autophagy in senescence and ageing. Nat Cell Biol 22, 1170–1179 (2020). https://doi.org/10.1038/s41556-020-00...)

This will introduce you to sirtuins and the concept of autophagy and how it seems what we previously thought was just a cytoplasmic targeting process, may have multiple nuclear targets as well.

Timestamps:
Intro - 00:00
Background - 00:45
Results - senescence - 03:18
Autophagy - 05:12
Aging - 07:30
Thoughts - 08:20

Additional references;
Dang, W., Steffen, K., Perry, R. et al. Histone H4 lysine 16 acetylation regulates cellular lifespan. Nature 459, 802–807 (2009). https://doi.org/10.1038/nature08085

I use Brave browser, check it out and download for free and earn BAT for browsing: https://brave.com/jaw125

Icons in intro; "https://www.freepik.com/free-photos-v..."Background vector created by freepik - www.freepik.com