Myofibrillar proteins titin and myomesin stimulated myoblast proliferation as determined by MTT-test and labelled thymidine incorporation in the DNA. Specific Fn type III and Ig-like domains of these proteins were able to exert mitogenic effects as well. Proliferative effect of Fn type III domains was highly sensitive to inhibition of Ca2+/calmodulin dependent protein kinase, whereas the effect of Ig-like domains showed greater sensitivity to the inhibition of adenylyl cyclase – cAMP – PKA pathway. IGF-1 autocrine signalling inhibition partially suppressed mitogenic effects revealed by both domain types.
Kravchenko, I. V., Furalyov, V. A., & Popov, V. O. (2017). Specific titin and myomesin domains stimulate myoblast proliferation. Biochemistry and Biophysics Reports, 9, 226–231. https://doi.org/10.1016/j.bbrep.2016.12.007