An RNA recognition motif (RRM) is required for the localization of PTB-associated splicing factor (PSF) to subnuclear speckles.

摘要: Using fusions with green fluorescent protein (GFP), we have identified sequences in the polypyrimidine tract binding protein-associated splicing factor (PSF) that are involved nuclear and subnuclear localization. Like other factors, PSF localizes to nucleus, is absent from nucleoli, accumulates punctate structures within nucleus referred as speckles. However, lacks known speckle localization domains been proteins. Instead, of speckles dependent on an RNA recognition motif (RRM). comprises N-terminal proline- glutamine-rich domain, two RRMs (RRM1 RRM2), a C-terminal region contains signals, both which required for complete Deletion RRM2 led loss resulted diffuse accumulation indicating Thus, appears localize through novel pathway its second RRM. Consistent use targeting pathway, redistributes perinucleolar clusters upon addition transcription inhibitor whereas factors display increased absence transcription. A yeast two-hybrid screen four-and-a-half LIM-only 2 (FHL2) potential interaction partner, possible role zinc-finger or LIM