title: Glutamine deprivation induces the expression of GADD45 and GADD153 primarily by mRNA stabilization.
abstract: The expression of the growth arrest- and DNA damage-inducible genes, GADD45 and GADD153/CHOP (C/EBP-homologous protein), as well as GRP78 (glucose-regulated protein of 78 kDa) was examined in several human breast cell lines subjected to acute glutamine (GLN) deprivation. GLN deprivation caused rapid elevation of GADD45 and GADD153/CHOP mRNA levels in cells that were highly dependent upon GLN for growth and viability. Both GADD mRNAs were rapidly elevated up to several hundred-fold. In contrast, GRP78 expression was elevated by no more than 4-fold by GLN deprivation. The magnitude of GADD up-regulation roughly correlated with the extent of GLN dependence of each cell line. The levels of all three mRNAs were responsive to alterations of ambient GLN content in a physiologically relevant concentration range that corresponded to the affinities of cellular GLN transporters. Provision of GLN-derived metabolites partially inhibited the induction of GADD expression in GLN-deprived cells. Nuclear run-on assays and mRNA decay studies suggested that the primary mechanism leading to increased GADD mRNA levels was not transcriptional, but rather that GADD45 and GADD153/CHOP expression were up-regulated in response to GLN deprivation via marked stabilization of these mRNAs. These results suggest that the expression of GADD genes contributes to growth arrest and/or protection from metabolic damage during GLN-poor conditions.
authors.affiliation: Surgical Oncology Research Laboratories, Massachusetts General Hospital, Department of Surgery, Harvard Medical School, Boston, Massachusetts 02114-2696, USA. SFAbcouwer@salud.unm.edu
authors.forename: S F
authors.initials: SF
authors.lastname: Abcouwer
authors.forename: C
authors.initials: C
authors.lastname: Schwarz
authors.forename: R A
authors.initials: RA
authors.lastname: Meguid
mesh_terms: D001943:Breast Neoplasms / Q000378:metabolism / Q000473:pathology; D022762:CCAAT-Enhancer-Binding Proteins; D002352:Carrier Proteins / Q000235:genetics; D002455:Cell Division; D002460:Cell Line; D004268:DNA-Binding Proteins / Q000235:genetics*; D000091342:Endoplasmic Reticulum Chaperone BiP; D005973:Glutamine / Q000172:deficiency*; D006360:Heat-Shock Proteins; D006801:Humans; D006868:Hydrolysis; D047908:Intracellular Signaling Peptides and Proteins; D018832:Molecular Chaperones / Q000235:genetics; D011506:Proteins / Q000235:genetics*; D012333:RNA, Messenger / Q000235:genetics* / Q000378:metabolism; D051742:Transcription Factor CHOP; D014157:Transcription Factors / Q000235:genetics*; D014158:Transcription, Genetic; D014407:Tumor Cells, Cultured; D000097642:GADD45 Proteins
chemical_list: D022762:CCAAT-Enhancer-Binding Proteins; D002352:Carrier Proteins; D004268:DNA-Binding Proteins; D000091342:Endoplasmic Reticulum Chaperone BiP; D005973:Glutamine; D006360:Heat-Shock Proteins; D047908:Intracellular Signaling Peptides and Proteins; D018832:Molecular Chaperones; D011506:Proteins; D012333:RNA, Messenger; D051742:Transcription Factor CHOP; D014157:Transcription Factors; D000097642:GADD45 Proteins; C497249:DDIT3 protein, human; C000717247:HSPA5 protein, human