The growth and tumor suppressor NORE1A is a cytoskeletal protein that suppresses growth by inhibition of the ERK pathway.
NORE1A is a growth and tumor suppressor that is inactivated in a variety of cancers. NORE1A has been shown to bind to the active Ras oncogene product. However, the mechanism of NORE1A-induced growth arrest and tumor suppression remains unknown. Using anchorage-independent growth assays, we mapped the NORE1A effector domain (the minimal region of the protein responsible for its growth-suppressive effects) to the fragment containing the central and Ras association domains of NORE1A (amino acids 191-363). Expression of the NORE1A effector domain in A549 lung adenocarcinoma cells resulted in the selective inhibition of signal transduction through the ERK pathway. The full-length NORE1A (416 amino acids) and its fragments capable of growth suppression were localized to centrosomes and microtubules in normal and transformed human cells in a Ras-independent manner. A mutant that was deficient in binding to centrosomes and microtubules was also deficient in inducing cell cycle arrest. This suggests that cytoskeletal localization is required for growth-suppressive effects of NORE1A. Ras binding function was required for growth-suppressive effects of the full-length NORE1A but not for the growth-suppressive effects of the effector domain. Our studies suggest that association of NORE1A with cytoskeletal elements is essential for NORE1A-induced growth suppression and that the ERK pathway is a target for NORE1A growth-suppressive activities.
Moshnikova
Anna
A
Department of Pathology, University of Virginia Health Science Center, Charlottesville, Virginia 22908, USA.
Frye
Judson
J
Shay
Jerry W
JW
Minna
John D
JD
Khokhlatchev
Andrei V
AV
D048868:Adaptor Proteins, Signal Transducing; D051017:Apoptosis Regulatory Proteins; D015153:Blotting, Western; D001980:Bronchi / Q000378:metabolism; D002453:Cell Cycle; D002460:Cell Line; D002461:Cell Line, Transformed; D045744:Cell Line, Tumor; D049109:Cell Proliferation; D018385:Centrosome / Q000378:metabolism; D050759:Cyclin-Dependent Kinase Inhibitor p21 / Q000378:metabolism; D003599:Cytoskeleton / Q000378:metabolism*; D015536:Down-Regulation; D004847:Epithelial Cells / Q000378:metabolism; D048049:Extracellular Signal-Regulated MAP Kinases / Q000378:metabolism*; D005434:Flow Cytometry; D015972:Gene Expression Regulation, Neoplastic; D016147:Genes, Tumor Suppressor; D049452:Green Fluorescent Proteins / Q000378:metabolism; D006801:Humans; D047468:Immunoprecipitation; D020935:MAP Kinase Signaling System; D008856:Microscopy, Fluorescence; D008870:Microtubules / Q000378:metabolism; D020928:Mitogen-Activated Protein Kinases / Q000378:metabolism; D020559:Monomeric GTP-Binding Proteins / Q000378:metabolism / Q000502:physiology*; D009154:Mutation; D010957:Plasmids / Q000378:metabolism; D011485:Protein Binding; D017434:Protein Structure, Tertiary; D012190:Retroviridae / Q000235:genetics / Q000378:metabolism; D015398:Signal Transduction; D014162:Transfection; D014404:Tubulin / Q000737:chemistry; D018631:ras Proteins / Q000378:metabolism
D048868:Adaptor Proteins, Signal Transducing; D051017:Apoptosis Regulatory Proteins; D050759:Cyclin-Dependent Kinase Inhibitor p21; C454042:RASSF5 protein, human; D014404:Tubulin; D049452:Green Fluorescent Proteins; D048049:Extracellular Signal-Regulated MAP Kinases; D020928:Mitogen-Activated Protein Kinases; D020559:Monomeric GTP-Binding Proteins; D018631:ras Proteins