TY - JOUR
T1 - New roles for lamins, nuclear envelope proteins and actin in the nucleus
AU - Maraldi, Nadir M.
AU - Lattanzi, Giovanna
AU - Marmiroli, Sandra
AU - Squarzoni, Stefano
AU - Manzoli, Francesco A.
PY - 2004
Y1 - 2004
N2 - To face the problem of the pathogenesis of different laminopathies, the regulation of the expression of nuclear structural proteins in various tissues has been investigated, mainly in muscle tissue that is affected in some of them. Developmental regulation of lamin A/C has been demonstrated during myoblast differentiation. An interaction specifically occurring in muscle cells is likely to provide lamin A/C with a muscle tissue-specific reactivity. A possible candidate for this interaction is actin, whose expression of cytoskeletal isoforms is down-regulated during muscle differentiation, while sarcomeric actin expression is induced. In this study, aimed to demonstrate a developmental regulation of the interaction among these nuclear structural proteins, we provide evidence that lamin A/C and emerin are bound to nuclear actin isoforms mainly at the late stages of myotube differentiation and in mature muscle cells. In cycling myoblasts, emerin binding is obtained by a serine-threonine phosphatase activity added to either whole extracts or nuclear extracts. On the contrary, this binding is prevented by active protein phosphatase 1 (PP1), a phosphatase that associates with lamin A/C. These data provide evidence of a modulation of emerin-lamin A/C-actin interactions in muscle cells, possibly through differentiation-related stimuli and indicate that nuclear proteins, including lamins, inner nuclear membrane-associated proteins and actin, once considered to play pure structural roles, are responsible for the modulation of key nuclear functions.
AB - To face the problem of the pathogenesis of different laminopathies, the regulation of the expression of nuclear structural proteins in various tissues has been investigated, mainly in muscle tissue that is affected in some of them. Developmental regulation of lamin A/C has been demonstrated during myoblast differentiation. An interaction specifically occurring in muscle cells is likely to provide lamin A/C with a muscle tissue-specific reactivity. A possible candidate for this interaction is actin, whose expression of cytoskeletal isoforms is down-regulated during muscle differentiation, while sarcomeric actin expression is induced. In this study, aimed to demonstrate a developmental regulation of the interaction among these nuclear structural proteins, we provide evidence that lamin A/C and emerin are bound to nuclear actin isoforms mainly at the late stages of myotube differentiation and in mature muscle cells. In cycling myoblasts, emerin binding is obtained by a serine-threonine phosphatase activity added to either whole extracts or nuclear extracts. On the contrary, this binding is prevented by active protein phosphatase 1 (PP1), a phosphatase that associates with lamin A/C. These data provide evidence of a modulation of emerin-lamin A/C-actin interactions in muscle cells, possibly through differentiation-related stimuli and indicate that nuclear proteins, including lamins, inner nuclear membrane-associated proteins and actin, once considered to play pure structural roles, are responsible for the modulation of key nuclear functions.
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U2 - 10.1016/j.advenzreg.2003.11.005
DO - 10.1016/j.advenzreg.2003.11.005
M3 - Article
C2 - 15581488
AN - SCOPUS:9644260867
VL - 44
SP - 155
EP - 172
JO - Advances in Enzyme Regulation
JF - Advances in Enzyme Regulation
SN - 0065-2571
IS - 1
ER -