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Anna Innocenzi,
Lucia Latella,
Graziella Messina,
Marta Simonatto,
Fabrizia Marullo,
Libera Berghella,
Coralie Poizat, Chih-Wen Shu,
Jean Y J Wang,
Pier Lorenzo Puri,
Giulio Cossu
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ABSTRACT: Despite having distinct expression patterns and phenotypes in mutant mice, the myogenic regulatory factors Myf5 and MyoD have been considered to be functionally equivalent. Here, we report that these factors have a different response to DNA damage, due to the presence in MyoD and absence in Myf5 of a consensus site for Abl-mediated tyrosine phosphorylation that inhibits MyoD activity in response to DNA damage. Genotoxins failed to repress skeletal myogenesis in MyoD-null embryos; reintroduction of wild-type MyoD, but not mutant Abl phosphorylation-resistant MyoD, restored the DNA-damage-dependent inhibition of muscle differentiation. Conversely, introduction of the Abl-responsive phosphorylation motif converts Myf5 into a DNA-damage-sensitive transcription factor. Gene-dosage-dependent reduction of Abl kinase activity in MyoD-expressing cells attenuated the DNA-damage-dependent inhibition of myogenesis. The presence of a DNA-damage-responsive phosphorylation motif in vertebrate, but not in invertebrate MyoD suggests an evolved response to environmental stress, originated from basic helix-loop-helix gene duplication in vertebrate myogenesis.
EMBO Reports 02/2011; 12(2):164-71. · 7.36 Impact Factor
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Anna Innocenzi,
Lucia Latella,
Graziella Messina,
Marta Simonatto,
Fabrizia Marullo,
Libera Berghella,
Coralie Poizat, Chih-Wen Shu,
Jean Y J Wang,
Pier Lorenzo Puri,
Giulio Cossu
[show abstract]
[hide abstract]
ABSTRACT: Despite having distinct expression patterns and phenotypes in mutant mice, the myogenic regulatory factors Myf5 and MyoD have been considered to be functionally equivalent. Here, we report that these factors have a different response to DNA damage, due to the presence in MyoD and absence in Myf5 of a consensus site for
EMBO Reports 01/2011; 12(2):164-171. · 7.36 Impact Factor
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ABSTRACT: An effective, noninvasive means of selecting cells based on their phase within the cell cycle is an important capability for biological research. Current methods of producing synchronous cell populations, however, tend to disrupt the natural physiology of the cell or suffer from low synchronization yields. In this work, we report a microfluidic device that utilizes the dielectrophoresis phenomenon to synchronize cells by exploiting the relationship between the cell's volume and its phase in the cell cycle. The dielectrophoresis activated cell synchronizer (DACSync) device accepts an asynchronous mixture of cells at the inlet, fractionates the cell populations according to the cell-cycle phase (G(1)/S and G(2)/M), and elutes them through different outlets. The device is gentle and efficient; it utilizes electric fields that are 1-2 orders of magnitude below those used in electroporation and enriches asynchronous tumor cells in the G(1) phase to 96% in one round of sorting, in a continuous flow manner at a throughput of 2 x 10(5) cells per hour per microchannel. This work illustrates the feasibility of using laminar flow and electrokinetic forces for the efficient, noninvasive separation of living cells.
Proceedings of the National Academy of Sciences 01/2008; 104(52):20708-12. · 9.68 Impact Factor
