Disassembly of interchromatin granule clusters alters the coordination of transcription and pre-mRNA splicing.

ABSTRACT: To examine the involvement of interchromatin granule clusters (IGCs) in transcription and pre-mRNA splicing in mammalian cell nuclei, the serine-arginine (SR) protein kinase cdc2-like kinase (Clk)/STY was used as a tool to manipulate IGC integrity in vivo. Both immunofluorescence and transmission electron microscopy analyses of cells overexpressing Clk/STY indicate that IGC components are completely redistributed to a diffuse nuclear localization, leaving no residual structure. Conversely, overexpression of a catalytically inactive mutant, Clk/STY(K190R), causes retention of hypophosphorylated SR proteins in nuclear speckles. Our data suggest that the protein-protein interactions responsible for the clustering of interchromatin granules are disrupted when SR proteins are hyperphosphorylate

SUBMITTER: Sacco-Bubulya P 

PROVIDER: S-EPMC2173333 | biostudies-literature | 2002 Feb

REPOSITORIES: biostudies-literature