title: Nerve growth factor regulates the expression and activity of p33cdk2 and p34cdc2 kinases in PC12 pheochromocytoma cells.
abstract: In the absence of serum, nerve growth factor (NGF) promotes the survival and differentiation of the PC12 pheochromocytoma cell line. In the presence of serum, NGF acts primarily as a differentiation factor and negative regulator of cell cycling. To investigate NGF control of cell cycling, we have analyzed the regulation of cyclin dependent kinases during PC12 cell differentiation. NGF treatment leads to a reduction in the steady-state protein levels of p33cdk2 and p34cdc2, two key regulators of cell cycle progression. The decrease in p33cdk2 and p34cdc2 coincides with a decrease in the enzymatic activity of cyclinA-p34cdc2, cyclinB-p34cdc2, cyclinE-p33cdk2, and cyclinA-p33cdk2 kinases. The decline in p33cdk2 and p34cdc2 kinase activity in response to NGF is accelerated in cells that over-express the p140trk NGF receptor, suggesting that the timing of the down- regulation is dependent on the level of p140trk and the strength of the NGF signal. The level of cyclin A, a regulatory subunit of p33cdk2 and p34cdc2, is relatively constant during PC12 differentiation. Nevertheless, the DNA binding activity of the cyclinA-associated transcription factor E2F/DP decreases. Thus, NGF down-regulates the activity of cyclin dependent kinases and cyclin-transcription factor complexes during PC12 differentiation.
authors.affiliation: Howard Hughes Medical Institute, Department of Biochemistry, New York University Medical Center, New York 10016.
authors.forename: K J
authors.initials: KJ
authors.lastname: Buchkovich
authors.forename: E B
authors.initials: EB
authors.lastname: Ziff
mesh_terms: D000595:Amino Acid Sequence; D000818:Animals; D001483:Base Sequence; D016203:CDC2 Protein Kinase / Q000378:metabolism*; D042846:CDC2-CDC28 Kinases; D002352:Carrier Proteins; D002453:Cell Cycle / Q000235:genetics / Q000502:physiology; D018797:Cell Cycle Proteins; D002454:Cell Differentiation; D002455:Cell Division / Q000187:drug effects / Q000502:physiology; D002462:Cell Membrane; D051357:Cyclin-Dependent Kinase 2; D018844:Cyclin-Dependent Kinases / Q000378:metabolism*; D016213:Cyclins / Q000378:metabolism; D004261:DNA Replication; D004268:DNA-Binding Proteins; D015536:Down-Regulation; D050684:E2F Transcription Factors; D008565:Membrane Proteins; D008969:Molecular Sequence Data; D009414:Nerve Growth Factors / Q000494:pharmacology*; D009687:Nuclear Proteins / Q000378:metabolism; D016716:PC12 Cells; D017346:Protein Serine-Threonine Kinases / Q000378:metabolism*; D051381:Rats; D017475:Receptors, Nerve Growth Factor / Q000378:metabolism; D056465:Retinoblastoma-Binding Protein 1; D050680:Transcription Factor DP1; D014157:Transcription Factors / Q000378:metabolism
chemical_list: D002352:Carrier Proteins; D018797:Cell Cycle Proteins; D016213:Cyclins; D004268:DNA-Binding Proteins; D050684:E2F Transcription Factors; D008565:Membrane Proteins; D009414:Nerve Growth Factors; D009687:Nuclear Proteins; D017475:Receptors, Nerve Growth Factor; D056465:Retinoblastoma-Binding Protein 1; D050680:Transcription Factor DP1; D014157:Transcription Factors; D017346:Protein Serine-Threonine Kinases; D016203:CDC2 Protein Kinase; D042846:CDC2-CDC28 Kinases; C495892:Cdk2 protein, rat; D051357:Cyclin-Dependent Kinase 2; D018844:Cyclin-Dependent Kinases