The distribution of phosphorylated SR proteins and alternative splicing are regulated by RANBP2
Por:
Saitoh N., Sakamoto C., Hagiwara M., Agredano-Moreno L.T., Jimenez-Garcia, LF, Nakao M.
Publicada:
15 mar 2012
Resumen:
The mammalian cell nucleus is functionally compartmentalized into various substructures. Nuclear speckles, also known as interchromatin granule clusters, are enriched with SR splicing factors and are implicated in gene expression. Here we report that nuclear speckle formation is developmentally regulated; in certain cases phosphorylated SR proteins are absent from the nucleus and are instead localized at granular structures in the cytoplasm. To investigate how the nuclear architecture is formed, we performed a phenotypic screen of HeLa cells treated with a series of small interfering RNAs. Depletion of Ran-binding protein 2 induced cytoplasmic intermediates of nuclear speckles in G1 phase. Detailed analyses of these structures suggested that a late step in the sequential nuclear entry of mitotic interchromatin granule components was disrupted and that phosphorylated SR proteins were sequestered in an SR protein kinase-dependent manner. As a result, the cells had an imbalanced subcellul
Filiaciones:
Saitoh N.:
Department of Medical Cell Biology, Institute of Molecular Embryology and Genetics, Kumamoto University, 2- Honjo, Kumamoto 860-0811, Japan
Sakamoto C.:
Department of Medical Cell Biology, Institute of Molecular Embryology and Genetics, Kumamoto University, 2- Honjo, Kumamoto 860-0811, Japan
Hagiwara M.:
Department of Anatomy and Developmental Biology, Graduate School of Medicine, Kyoto University, Sakyo-ku, Kyoto 606-8501, Japan
Agredano-Moreno L.T.:
Univ Nacl Autonoma Mexico, Fac Sci, Dept Cell Biol, Mexico City 04510, DF, Mexico
Jimenez-Garcia, LF:
Univ Nacl Autonoma Mexico, Fac Sci, Dept Cell Biol, Mexico City 04510, DF, Mexico
Nakao M.:
Department of Medical Cell Biology, Institute of Molecular Embryology and Genetics, Kumamoto University, 2- Honjo, Kumamoto 860-0811, Japan
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