The Drosophila tuberous sclerosis complex gene homologs restrict cell growth and cell proliferation.
The inherited human disease tuberous sclerosis, characterized by hamartomatous tumors, results from mutations in either TSC1 or TSC2. We have characterized mutations in the Drosophila Tsc1 and Tsc2/gigas genes. Inactivating mutations in either gene cause an identical phenotype characterized by enhanced growth and increased cell size with no change in ploidy. Overall, mutant cells spend less time in G1. Coexpression of both Tsc1 and Tsc2 restricts tissue growth and reduces cell size and cell proliferation. This phenotype is modulated by manipulations in cyclin levels. In postmitotic mutant cells, levels of Cyclin E and Cyclin A are elevated. This correlates with a tendency for these cells to reenter the cell cycle inappropriately as is observed in the human lesions.
Tapon
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Massachusetts General Hospital Cancer Center, Charlestown, MA 02129, USA.
Ito
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Dickson
B J
BJ
Treisman
J E
JE
Hariharan
I K
IK
D000818:Animals; D002453:Cell Cycle / Q000502:physiology*; D048429:Cell Size; D019925:Cyclin A / Q000378:metabolism; D019927:Cyclin E / Q000378:metabolism; D004247:DNA / Q000378:metabolism; D004331:Drosophila melanogaster / Q000166:cytology / Q000235:genetics / Q000502:physiology; D005260:Female; D005434:Flow Cytometry; D005456:Fluorescent Dyes / Q000378:metabolism; D016147:Genes, Tumor Suppressor / Q000235:genetics*; D049452:Green Fluorescent Proteins; D006801:Humans; D007150:Immunohistochemistry; D019476:Insect Proteins / Q000235:genetics / Q000378:metabolism; D008164:Luminescent Proteins / Q000235:genetics / Q000378:metabolism; D008297:Male; D010641:Phenotype; D017956:Photoreceptor Cells, Invertebrate / Q000166:cytology* / Q000502:physiology / Q000648:ultrastructure; D011003:Ploidies; D011506:Proteins / Q000235:genetics* / Q000378:metabolism; D012097:Repressor Proteins / Q000235:genetics* / Q000378:metabolism; D014402:Tuberous Sclerosis / Q000235:genetics* / Q000503:physiopathology; D000077004:Tuberous Sclerosis Complex 1 Protein; D000077005:Tuberous Sclerosis Complex 2 Protein; D025521:Tumor Suppressor Proteins
D019925:Cyclin A; D019927:Cyclin E; D005456:Fluorescent Dyes; D019476:Insect Proteins; D008164:Luminescent Proteins; D011506:Proteins; D012097:Repressor Proteins; C000624650:TSC1 protein, human; C000624653:TSC2 protein, human; D000077004:Tuberous Sclerosis Complex 1 Protein; D000077005:Tuberous Sclerosis Complex 2 Protein; D025521:Tumor Suppressor Proteins; D049452:Green Fluorescent Proteins; D004247:DNA