Dynein light chain association sequences can facilitate nuclear protein import.
Nuclear localization sequence (NLS)-dependent nuclear protein import is not conventionally held to require interaction with microtubules (MTs) or components of the MT motor, dynein. Here we report for the first time the role of sequences conferring association with dynein light chains (DLCs) in NLS-dependent nuclear accumulation of the rabies virus P-protein. We find that P-protein nuclear accumulation is significantly enhanced by its dynein light chain association sequence (DLC-AS), dependent on MT integrity and association with DLCs, and that P-protein-DLC complexes can associate with MT cytoskeletal structures. We also find that P-protein DLC-AS, as well as analogous sequences from other proteins, acts as an independent module that can confer enhancement of nuclear accumulation to proteins carrying the P-protein NLS, as well as several heterologous NLSs. Photobleaching experiments in live cells demonstrate that the MT-dependent enhancement of NLS-mediated nuclear accumulation by the P-protein DLC-AS involves an increased rate of nuclear import. This is the first report of DLC-AS enhancement of NLS function, identifying a novel mechanism regulating nuclear transport with relevance to viral and cellular protein biology. Importantly, this data indicates that DLC-ASs represent versatile modules to enhance nuclear delivery with potential therapeutic application.
Moseley
Gregory W
GW
Nuclear Signalling Laboratory, Department of Biochemistry and Molecular Biology, Monash University, Monash, Victoria 3800, Australia.
Roth
Daniela Martino
DM
DeJesus
Michelle A
MA
Leyton
Denisse L
DL
Filmer
Richard P
RP
Pouton
Colin W
CW
Jans
David A
DA
D021581:Active Transport, Cell Nucleus; D000595:Amino Acid Sequence; D000818:Animals; D000952:Antigens, Polyomavirus Transforming / Q000378:metabolism; D001665:Binding Sites; D019556:COS Cells; D002467:Cell Nucleus / Q000378:metabolism*; D002470:Cell Survival; D002522:Chlorocebus aethiops; D004398:Dyneins / Q000737:chemistry* / Q000378:metabolism*; D006367:HeLa Cells; D006801:Humans; D008870:Microtubules / Q000378:metabolism; D018832:Molecular Chaperones; D019913:Nuclear Localization Signals; D010750:Phosphoproteins / Q000378:metabolism*; D011485:Protein Binding; D011993:Recombinant Fusion Proteins / Q000378:metabolism; D013329:Structure-Activity Relationship; D015678:Viral Structural Proteins / Q000378:metabolism*
D000952:Antigens, Polyomavirus Transforming; D018832:Molecular Chaperones; D019913:Nuclear Localization Signals; C103961:P phosphoprotein, Rabies virus; D010750:Phosphoproteins; D011993:Recombinant Fusion Proteins; D015678:Viral Structural Proteins; D004398:Dyneins