Phosphoproteomic analysis reveals enhanced PKA signaling in aged skeletal muscle is suppressed by caloric restriction

ABSTRACT: Although caloric restriction (CR) was first shown to extend the lifespan of rodents over 75 years ago, the underlying mechanisms remain unclear. Additionally, the majority of published studies have focused on the effects of short-term CR. To better understand cell signaling alterations in a tissue known to be highly impacted by CR, we sought to assess the impact of aging and lifelong CR on skeletal muscle protein phosphorylation dynamics. We performed phosphoproteomic analysis on skeletal muscle from young mice, old mice fed on an ad libitum diet, and old mice fed a CR diet. This analysis revealed distinct phosphoproteomic signatures associated with both aging and diet. Importantly, CR appeared to promote a signature that was more similar to young mice than old mice fed on an ad lib diet. From the phosphorylation measurements on its known substrates, we deciphered that aging promotes Protein kinase A (PKA) signaling, and CR inhibits this signaling cascade. Given the demonstrated role of PKA signaling as a “pro-aging” pathway in various model organisms, including yeast and mice, we propose that CR exerts its longevity-enhancing effects partially via the suppression of this pathway.

ORGANISM(S): Mus Musculus (mouse)

SUBMITTER: James P. White 

PROVIDER: PXD018455 | JPOST Repository | Sat Jan 30 00:00:00 GMT 2021

REPOSITORIES: jPOST