Identification of a tripartite import signal in the Ewing Sarcoma protein (EWS).
The Ewing Sarcoma (EWS) protein is a ubiquitously expressed RNA processing factor that localises predominantly to the nucleus. However, the mechanism through which EWS enters the nucleus remains unclear, with differing reports identifying three separate import signals within the EWS protein. Here we have utilized a panel of truncated EWS proteins to clarify the reported nuclear localisation signals. We describe three C-terminal domains that are important for efficient EWS nuclear localization: (1) the third RGG-motif; (2) the last 10 amino acids (known as the PY-import motif); and (3) the zinc-finger motif. Although these three domains are involved in nuclear import, they are not independently capable of driving the efficient import of a GFP-moiety. However, collectively they form a complex tripartite signal that efficiently drives GFP-import into the nucleus. This study helps clarify the EWS import signal, and the identification of the involvement of both the RGG- and zinc-finger motifs has wide reaching implications.
Shaw
Debra J
DJ
Clinical Neurobiology, IBCS, Peninsula College of Medicine and Dentistry, Exeter EX1 2LU, UK.
Morse
Robert
R
Todd
Adrian G
AG
Eggleton
Paul
P
Lorson
Christian L
CL
Young
Philip J
PJ
D021581:Active Transport, Cell Nucleus; D001859:Bone Neoplasms / Q000378:metabolism*; D002467:Cell Nucleus / Q000378:metabolism*; D003593:Cytoplasm / Q000378:metabolism; D004252:DNA Mutational Analysis; D006801:Humans; D009154:Mutation; D019913:Nuclear Localization Signals; D021382:Protein Sorting Signals; D034802:RNA-Binding Protein EWS / Q000235:genetics / Q000378:metabolism*; D012512:Sarcoma, Ewing / Q000378:metabolism*; D016335:Zinc Fingers
D019913:Nuclear Localization Signals; D021382:Protein Sorting Signals; D034802:RNA-Binding Protein EWS