An amino acid sequence motif sufficient for subnuclear localization of an arginine/serine-rich splicing factor.
We have identified an amino acid sequence in the Drosophila Transformer (Tra) protein that is capable of directing a heterologous protein to nuclear speckles, regions of the nucleus previously shown to contain high concentrations of spliceosomal small nuclear RNAs and splicing factors. This sequence contains a nucleoplasmin-like bipartite nuclear localization signal (NLS) and a repeating arginine/serine (RS) dipeptide sequence adjacent to a short stretch of basic amino acids. Sequence comparisons from a number of other splicing factors that colocalize to nuclear speckles reveal the presence of one or more copies of this motif. We propose a two-step subnuclear localization mechanism for splicing factors. The first step is transport across the nuclear envelope via the nucleoplasmin-like NLS, while the second step is association with components in the speckled domain via the RS dipeptide sequence.
Department of Molecular and Cellular Biology, Harvard University, Cambridge, MA 02138, USA.
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D000595:Amino Acid Sequence; D000818:Animals; D002451:Cell Compartmentation; D002467:Cell Nucleus / Q000378:metabolism* / Q000648:ultrastructure; D002478:Cells, Cultured; D003001:Cloning, Molecular; D029721:Drosophila Proteins; D005455:Fluorescent Antibody Technique; D016259:Genes, myc; D006367:HeLa Cells; D006801:Humans; D008969:Molecular Sequence Data; D009687:Nuclear Proteins / Q000235:genetics / Q000378:metabolism*; D010455:Peptides / Q000378:metabolism; D012326:RNA Splicing; D012261:Ribonucleoproteins / Q000235:genetics / Q000378:metabolism; D000068103:Serine-Arginine Splicing Factors; D013329:Structure-Activity Relationship; D014162:Transfection
D029721:Drosophila Proteins; D009687:Nuclear Proteins; D010455:Peptides; D012261:Ribonucleoproteins; C097162:Tra protein, Drosophila; C066174:tra2 protein, Drosophila; C073288:SRSF2 protein, human; D000068103:Serine-Arginine Splicing Factors