Activity-dependent nuclear translocation and intranuclear distribution of NFATc in adult skeletal muscle fibers

Citation
Yw. Liu et al., Activity-dependent nuclear translocation and intranuclear distribution of NFATc in adult skeletal muscle fibers, J CELL BIOL, 155(1), 2001, pp. 27-39
Citations number
59
Language
INGLESE
art.tipo
Article
Categorie Soggetti
Cell & Developmental Biology
Journal title
JOURNAL OF CELL BIOLOGY
ISSN journal
0021-9525 → ACNP
Volume
155
Issue
1
Year of publication
2001
Pages
27 - 39
Database
ISI
SICI code
0021-9525(20011001)155:1<27:ANTAID>2.0.ZU;2-T
Abstract
Transcription factor nuclear factor of activated T cells NFATc (NFATc1, NFA T2) may contribute to slow-twitch skeletal muscle fiber type-specific gene expression. Green fluorescence protein (GFP) or FLAG fusion proteins of eit her wild-type or constitutively active mutant NFATc [NFATc(S-->A)] were exp ressed in cultured adult mouse skeletal muscle fibers from flexor digitorum brevis (predominantly fast-twitch). Unstimulated fibers expressing NFATc(S -->A) exhibited a distinct intranuclear pattern of NFATc foci. In unstimula ted fibers expressing NFATc-GFP, fluorescence was localized at the sarcomer ic z-lines and absent from nuclei. Electrical stimulation using activity pa tterns typical of slow-twitch muscle, either continuously at 10 Hz or in 5- s trains at 10 Hz every 50 s, caused cyclosporin A-sensitive appearance of fluorescent foci of NFATc-GFP in all nuclei. Fluorescence of nuclear foci i ncreased during the first hour of stimulation and then remained constant du ring a second hour of stimulation. Kinase inhibitors and ionomycin caused a ppearance of nuclear foci of NFATc-GFP without electrical stimulation. Nucl ear translocation of NFATc-GFP did not occur with either continuous 1 Hz st imulation or with the fast-twitch fiber activity pattern of 0.1-s trains at 50 Hz every 50 s. The stimulation pattern-dependent nuclear translocation of NFATc demonstrated here could thus contribute to fast-twitch to slow-twi tch fiber type transformation.