A transiently expressed TRN-SR2 mutant lacking the N-terminal 281-amino acids, DeltaN281, localizes predominantly in the nucleoplasm and accumulates in speckled domains in the nuclei of HeLa cells (Lai, 2000). To test whether deletion of the N-terminal domain of Trn-SR could similarly affect its cellular distribution, GFP was fused in frame to the N terminus of full-length Trn-SR or its truncated version lacking the first N-terminal 217-amino acids, DeltaN217, and transiently expressed fusion proteins in either HeLa cells or Drosophila S2 cells. In both cell lines, full-length Trn-SR fusion protein is detected both in the nucleus and the cytoplasm. In contrast, DeltaN217 is localized predominantly in the nucleus. Immunofluorescence with anti-SC35 antibodies clearly established that a Trn-SR mutant lacking the N-terminal region localizes to the nucleus of HeLa cells in a speckled pattern that coincides with the distribution of the SR protein SC35. Altogether, the results show that Trn-SR has the same localization properties as hTRN-SR2, suggesting that Trn-SR is the import receptor for Drosophila SR proteins (Allemand, 2002).
Reference names in red indicate recommended papers.
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Allemand, E., Dokudovskaya, S., Bordonne, R. and Tazi, J. (2002). A conserved Drosophila transportin-serine/arginine-rich (SR) protein permits nuclear import of Drosophila SR protein splicing factors and their antagonist repressor splicing factor 1. Mol. Biol. Cell 13(7): 2436-47. 12134081
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date revised: 10 June 2005
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