Negative regulation of cell growth and differentiation by TSG101 through association with p21(Cip1/WAF1).
TSG101 was discovered in a screen for tumor susceptibility genes and has since been shown to have a multiplicity of biological effects. However, the basis for TSG101's ability to regulate cell growth has not been elucidated. We report here that the TSG101 protein binds to the cyclin/cyclin-dependent kinase (CDK) inhibitor (CKI) p21(Cip1/WAF1) and increases stability of the p21 protein in HEK293F cells and differentiating primary keratinocytes, suppressing differentiation in a p21-dependent manner. In proliferating keratinocytes where the p21 protein is relatively stable, TSG101 does not affect the stability or expression of p21 but shows p21-dependent recruitment to cyclin/CDK complexes, inhibits cyclin/CDK activity, and causes strong growth suppression to a much greater extent in p21+/+ than in p21-/- cells. Conversely, suppression of endogenous TSG101 expression by an antisense TSG101 cDNA causes doubling of the fraction of keratinocytes in the S phase of the cell cycle as occurs during p21 deficiency. Our results indicate that TSG101 has a direct role in the control of growth and differentiation in primary epithelial cells, and that p21 is an important mediator of these TSG101 functions.
Oh
Hyesun
H
Cutaneous Biology Research Center, Massachusetts General Hospital and Harvard Medical School, Charlestown, MA 02129, USA.
Mammucari
Cristina
C
Nenci
Arianna
A
Cabodi
Sara
S
Cohen
Stanley N
SN
Dotto
G Paolo
GP
D000818:Animals; D042846:CDC2-CDC28 Kinases; D002454:Cell Differentiation; D002455:Cell Division; D002460:Cell Line; D051357:Cyclin-Dependent Kinase 2; D050759:Cyclin-Dependent Kinase Inhibitor p21; D018844:Cyclin-Dependent Kinases / Q000378:metabolism; D016213:Cyclins / Q000737:chemistry / Q000502:physiology*; D018076:DNA, Complementary / Q000378:metabolism; D004268:DNA-Binding Proteins / Q000737:chemistry / Q000502:physiology*; D015536:Down-Regulation; D056827:Endosomal Sorting Complexes Required for Transport; D049452:Green Fluorescent Proteins; D006801:Humans; D015603:Keratinocytes / Q000378:metabolism; D008164:Luminescent Proteins / Q000378:metabolism; D051379:Mice; D016376:Oligonucleotides, Antisense / Q000737:chemistry; D010766:Phosphorylation; D011233:Precipitin Tests; D011485:Protein Binding; D017346:Protein Serine-Threonine Kinases / Q000378:metabolism; D011993:Recombinant Fusion Proteins / Q000378:metabolism; D016160:Retinoblastoma Protein / Q000378:metabolism; D016196:S Phase; D013997:Time Factors; D014157:Transcription Factors / Q000737:chemistry / Q000502:physiology*; D014162:Transfection; D020798:Two-Hybrid System Techniques; D000099177:Tsg101 Protein
D042846:CDC2-CDC28 Kinases; D051357:Cyclin-Dependent Kinase 2; D050759:Cyclin-Dependent Kinase Inhibitor p21; D018844:Cyclin-Dependent Kinases; D016213:Cyclins; D018076:DNA, Complementary; D004268:DNA-Binding Proteins; D056827:Endosomal Sorting Complexes Required for Transport; D049452:Green Fluorescent Proteins; D008164:Luminescent Proteins; D016376:Oligonucleotides, Antisense; D017346:Protein Serine-Threonine Kinases; D011993:Recombinant Fusion Proteins; D016160:Retinoblastoma Protein; D014157:Transcription Factors; D000099177:Tsg101 Protein; C493956:CDKN1A protein, human; C493957:Cdkn1a protein, mouse; C495894:CDK2 protein, human; C495893:Cdk2 protein, mouse