ИСТИНА

In previous works we showed that myofibrillar proteins titin and myomesin stimulate expression of IGF-1 splice forms. However, it remains uninvestigated whether these stimulators activate myoblast proliferation. Here the ability of titin and myomesin as well as their certain domains to stimulate MTT reduction and [3H]-thymidine incorporation in DNA by myoblast cultures was shown.Earlier we have shown that stimulation of MGF and IGF-1Ea synthesis induced by Fn type III domains was more sensitive to inhibition of Ca2+/calmodulin dependent protein kinase activity, whereas the effect of Ig-like domains showed greater sensitivity to the inhibition of adenylyl cyclase – cAMP – PKA pathway. In present work we have described that stimulation of proliferation induced by domains of these two types demonstrate the same pattern of sensitivity to signaling pathway inhibitors.