title: Differential expression of gas and gadd genes at distinct growth arrest points during adipocyte development.
abstract: The characterization of growth arrest-associated genes has revealed that cells actively suppress mitotic growth in response to extracellular signals. Mouse 3T3-L1 cells growth arrest at multiple distinct points during terminal differentiation to adipocytes. We examined the expression of growth arrest-specific (gas) and growth arrest- and DNA damage-inducible (gadd) genes as a function of 3T3-L1 growth arrest and adipocyte development. These growth arrest-associated genes are differentially expressed throughout adipocyte development. Some of the gas/gadd genes are preferentially expressed in a subset of growth arrest states. In contrast, gas1 and gas3 are expressed in serum-starved adipoblasts, contact-inhibited adipoblasts, and post-mitotic adipocytes. However, in post-mitotic adipocytes, gas1 and gas3 are induced in response to nutrient deprivation, not altered growth status. gas6 is an exception to the general concordance of mitotic growth arrest and gas/gadd expression in that gas6 is preferentially expressed during the clonal expansion of postconfluent adipoblasts. Combined, the expression patterns indicate that growth arrest-associated genes are regulated by numerous signal transduction pathways throughout a discrete developmental transition.
authors.affiliation: Department of Biology, University of Virginia, Charlottesville 22903, USA.
authors.forename: E C
authors.initials: EC
authors.lastname: Shugart
authors.forename: A S
authors.initials: AS
authors.lastname: Levenson
authors.forename: C M
authors.initials: CM
authors.lastname: Constance
authors.forename: R M
authors.initials: RM
authors.lastname: Umek
mesh_terms: D016475:3T3 Cells; D017667:Adipocytes / Q000166:cytology* / Q000502:physiology; D000818:Animals; D001483:Base Sequence; D015152:Blotting, Northern; D002453:Cell Cycle; D018797:Cell Cycle Proteins; D016895:Culture Media, Serum-Free; D004249:DNA Damage; D017931:DNA Primers; D015342:DNA Probes; D016193:G1 Phase; D058851:GPI-Linked Proteins; D005786:Gene Expression Regulation; D047908:Intracellular Signaling Peptides and Proteins; D008562:Membrane Glycoproteins / Q000096:biosynthesis* / Q000235:genetics; D008565:Membrane Proteins; D051379:Mice; D008938:Mitosis; D008969:Molecular Sequence Data; D009185:Myelin Proteins / Q000096:biosynthesis* / Q000235:genetics; D014176:Protein Biosynthesis; D011506:Proteins / Q000235:genetics; D029701:Saccharomyces cerevisiae Proteins; D013997:Time Factors; D014158:Transcription, Genetic; D000097642:GADD45 Proteins
chemical_list: D018797:Cell Cycle Proteins; D016895:Culture Media, Serum-Free; D017931:DNA Primers; D015342:DNA Probes; D058851:GPI-Linked Proteins; D047908:Intracellular Signaling Peptides and Proteins; D008562:Membrane Glycoproteins; D008565:Membrane Proteins; D009185:Myelin Proteins; D011506:Proteins; D029701:Saccharomyces cerevisiae Proteins; D000097642:GADD45 Proteins; C066709:GAS1 protein, S cerevisiae; C096192:GAS1 protein, human; C501180:Gas1 protein, mouse; C489545:Pmp22 protein, mouse