REVIEW: New Titin (Connectin) Isoforms and Their Functional Role in Striated Muscles of Mammals: Facts and Suppositions

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I. M. Vikhlyantsev^1* and Z. A. Podlubnaya^1,2

¹Institute of Theoretical and Experimental Biophysics, Russian Academy of Sciences, ul. Institutskaya 3, 142290 Pushchino, Moscow Region, Russia; E-mail: vikhlyantsev@iteb.ru; vikhlyantsev@mail.iteb.ru

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

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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.

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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)

DOI: 10.1134/S0006297912130093

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