title: Cyclin-dependent kinases regulate lysosomal degradation of hypoxia-inducible factor 1α to promote cell-cycle progression.
abstract: Hypoxia-inducible factor 1 (HIF-1) is a transcription factor that mediates adaptive responses to oxygen deprivation. In addition, the HIF-1α subunit has a nontranscriptional role as a negative regulator of DNA replication through effects on minichromosome maintenance helicase loading and activation. However, some cell types continue to replicate under hypoxic conditions. The mechanism by which these cells maintain proliferation in the presence of elevated HIF-1α levels is unclear. Here we report that HIF-1α physically and functionally interacts with cyclin-dependent kinase 1 (Cdk1) and Cdk2. Cdk1 activity blocks lysosomal degradation of HIF-1α and increases HIF-1α protein stability and transcriptional activity. By contrast, Cdk2 activity promotes lysosomal degradation of HIF-1α at the G1/S phase transition. Blocking lysosomal degradation by genetic or pharmacological means leads to HIF-1α-dependent cell-cycle arrest, demonstrating that lysosomal degradation of HIF-1α is an essential step for the maintenance of cell-cycle progression under hypoxic conditions.
authors: Vascular Program, Institute for Cell Engineering,McKusick-Nathans Institute of Genetic Medicine.
authors: Maimon E
authors: ME
authors: Hubbi
authors: Vascular Program, Institute for Cell Engineering,McKusick-Nathans Institute of Genetic Medicine,Johns Hopkins Physical Sciences-Oncology Center, Johns Hopkins University, Baltimore, MD 21205; and.
authors: Daniele M
authors: DM
authors: Gilkes
authors: Vascular Program, Institute for Cell Engineering,McKusick-Nathans Institute of Genetic Medicine.
authors: Hongxia
authors: H
authors: Hu
authors: Department of Biomedical Engineering, Systems Biology Institute, Yale University, New Haven, CT 06520.
authors: Kshitiz
authors: Medical Scientist Training Program, and.
authors: Ishrat
authors: I
authors: Ahmed
authors: Vascular Program, Institute for Cell Engineering,McKusick-Nathans Institute of Genetic Medicine,Johns Hopkins Physical Sciences-Oncology Center, Johns Hopkins University, Baltimore, MD 21205; andDepartments of Pediatrics,Medicine,Oncology,Radiation Oncology, andBiological Chemistry, Johns Hopkins University School of Medicine, Baltimore, MD 21205; gsemenza@jhmi.edu.
authors: Gregg L
authors: GL
authors: Semenza
mesh_terms: D000818:Animals; D016203:CDC2 Protein Kinase / Q000378:metabolism*; D059447:Cell Cycle Checkpoints / Q000502:physiology*; D002460:Cell Line; D045744:Cell Line, Tumor; D051357:Cyclin-Dependent Kinase 2 / Q000037:antagonists & inhibitors / Q000235:genetics / Q000378:metabolism*; D059585:G1 Phase Cell Cycle Checkpoints / Q000502:physiology; D055785:Gene Knockdown Techniques; D006367:HeLa Cells; D006801:Humans; D051795:Hypoxia-Inducible Factor 1, alpha Subunit / Q000235:genetics / Q000378:metabolism*; D008247:Lysosomes / Q000378:metabolism*; D051379:Mice; D046988:Proteasome Endopeptidase Complex / Q000378:metabolism; D055550:Protein Stability; D059748:Proteolysis
chemical_list: C497442:HIF1A protein, human; C497443:Hif1a protein, mouse; D051795:Hypoxia-Inducible Factor 1, alpha Subunit; D016203:CDC2 Protein Kinase; C495894:CDK2 protein, human; C495893:Cdk2 protein, mouse; D051357:Cyclin-Dependent Kinase 2; D046988:Proteasome Endopeptidase Complex
keywords: cell proliferation; chaperone mediated autophagy; lysosome