title: Activation of polyubiquitin gene expression during developmentally programmed cell death.
abstract: Ubiquitin, a highly conserved 76 amino acid protein, plays a role in targeting intracellular proteins for degradation. Ubiquitin expression was examined during the developmentally programmed atrophy and degeneration of the intersegmental muscles (ISMs) in the hawk-moth, Manduca sexta. A clone containing nine repeats of the ubiquitin coding sequence was isolated from an ISM cDNA library and was used as a probe to examine polyubiquitin expression during development. When the ISMs became committed to degenerate, polyubiquitin gene expression increased dramatically. Injection of 20-hydroxyecdysone, which delays degeneration in this system, prevented the increase in polyubiquitin mRNA. The expression of polyubiquitin occurred without apparent activation of the cell's heat shock response. These data suggest that ubiquitin plays a role in programmed cell death.
authors.affiliation: Department of Zoology, Morrill Science Center, University of Massachusetts, Amherst 01003.
authors.forename: L M
authors.initials: LM
authors.lastname: Schwartz
authors.forename: A
authors.initials: A
authors.lastname: Myer
authors.forename: L
authors.initials: L
authors.lastname: Kosz
authors.forename: M
authors.initials: M
authors.lastname: Engelstein
authors.forename: C
authors.initials: C
authors.lastname: Maier
mesh_terms: D000818:Animals; D001483:Base Sequence; D002470:Cell Survival; D004247:DNA / Q000235:genetics; D005786:Gene Expression Regulation; D006360:Heat-Shock Proteins / Q000378:metabolism; D008969:Molecular Sequence Data; D009036:Moths; D024510:Muscle Development; D009132:Muscles / Q000473:pathology; D014452:Ubiquitins / Q000235:genetics* / Q000378:metabolism
chemical_list: D006360:Heat-Shock Proteins; D014452:Ubiquitins; D004247:DNA