title: Cell cycle regulated expression and phosphorylation of hpttg proto-oncogene product.
abstract: We recently isolated a cDNA for hpttg, the human homolog of rat pituitary tumor transforming gene. Now we have analysed the expression of hpttg as a function of cell proliferation. hPTTG protein level is up-regulated in rapidly proliferating cells, is down-regulated in response to serum starvation or cell confluence, and is regulated in a cell cycle-dependent manner, peaking in mitosis. In addition, we show that hPTTG is phosphorylated during mitosis. Immunodepletion and in vitro phosphorylation experiments, together with the use of a specific inhibitor, indicate that Cdc2 is the kinase that phosphorylates hPTTG. These results suggest that hpttg is induced by, and may have a role in, regulatory pathways involved in the control of cell proliferation.
authors.affiliation: Departamento de Microbiología, Facultad de Biología, Universidad de Seville, Spain.
authors.forename: F
authors.initials: F
authors.lastname: Ramos-Morales
authors.forename: A
authors.initials: A
authors.lastname: Domínguez
authors.forename: F
authors.initials: F
authors.lastname: Romero
authors.forename: R
authors.initials: R
authors.lastname: Luna
authors.forename: M C
authors.initials: MC
authors.lastname: Multon
authors.forename: J A
authors.initials: JA
authors.lastname: Pintor-Toro
authors.forename: M
authors.initials: M
authors.lastname: Tortolero
mesh_terms: D000595:Amino Acid Sequence; D000818:Animals; D016203:CDC2 Protein Kinase / Q000502:physiology; D019556:COS Cells; D002453:Cell Cycle; D002455:Cell Division; D006367:HeLa Cells; D006801:Humans; D008938:Mitosis; D008969:Molecular Sequence Data; D009363:Neoplasm Proteins / Q000378:metabolism*; D015513:Oncogene Proteins / Q000378:metabolism*; D010766:Phosphorylation; D000090063:Proto-Oncogene Mas; D064249:Securin; D018909:src Homology Domains
chemical_list: C000715470:MAS1 protein, human; D009363:Neoplasm Proteins; D015513:Oncogene Proteins; D000090063:Proto-Oncogene Mas; D064249:Securin; D016203:CDC2 Protein Kinase