Hi Brent, I will be covering a few studies on titin and its role as a signaling agent soon as infographics, because this is a very interesting area that seems to be developing quickly. I think it is now reasonably clear that titin acts to signal increases in sarcomeres in series (and therefore produce longitudinal muscle fiber growth), as well as being the main factor responsible for passive stiffness in muscle fibers.

Downsizing the molecular spring of the giant protein titin reveals that skeletal muscle titin…

I incorporated this study into my more recent article on the role of passive tension in muscle fiber hypertrophy signaling.

https://medium.com/@SandCResearch/how-does-the-length-tension-relationship-affect-hypertrophy-b0cc78043973