2Pushchino State Institute of Natural Sciences, pr. Nauki 3, 142290 Pushchino, Moscow Region, Russia
* To whom correspondence should be addressed.
Received May 25, 2012; Revision received June 19, 2012
This review summarizes results of our studies on titin isoform composition in vertebrate striated muscles under normal conditions, during hibernation, real and simulated microgravity, and under pathological conditions (stiff-person syndrome, post-apoplectic spasticity, dilated cardiomyopathy, cardiac hypertrophy). Experimental evidence for the existence in mammalian striated muscles of higher molecular weight isoforms of titin (NT-isoforms) in addition to the known N2A-, N2BA-, and N2B-titin isoforms was obtained. Comparative studies of changes in titin isoform composition and structure–functional properties of human and animal striated muscles during adaptive and pathological processes led to a conclusion about the key role of NT-isoforms of titin in maintenance of sarcomere structure and contractile function of these muscles.
KEY WORDS: skeletal and cardiac muscles, NT-, N2A-, N2BA- and N2B-isoforms of titin, T2-fragment, hibernation, microgravity, stiff-person syndrome, post-apoplectic spasticity, dilated cardiomyopathy, cardiac hypertrophy, spontaneously hypertensive rats (SHR)