title: Rapid turnover of GATA-2 via ubiquitin-proteasome protein degradation pathway.
abstract: Transcription factor GATA-2 is expressed in a number of tissues, including hematopoietic stem and progenitor cells, and is crucial for the proliferation and survival of hematopoietic cells. To further characterize the function of GATA-2, we examined the cellular turnover mechanism of GATA-2. In P815 cells, the half-life of endogenous GATA-2 was found to be as short as 30 min after cycloheximide treatment. This short half-life was reproducible in other hematopoietic and neuroblastoma cell lines with moderate variation. We also found that ultraviolet (UV)-C irradiation markedly represses the GATA-2 protein level by facilitating the degradation process. Since treatment of the cells with the proteasome inhibitor MG132 or clasto-Lactacystin substantially abrogated the effects of cycloheximide and UV-C irradiation and increased the expression level of both endogenous and transfected GATA-2, the degradation of GATA-2 seems to occur through the proteasome pathway. Structure-function analyses with the GAL4-DNA binding domain (GBD)-GATA-2 fusion protein and GATA-2 deletion mutants suggested that the protein degradation regulatory elements of GATA-2 reside in three regions, two of which overlap with the transactivation domain. We also detected poly ubiquitinated forms of GATA-2. Taken together, these results demonstrate that GATA-2 is turned over rapidly through the ubiquitin-proteasome pathway.
authors.affiliation: Graduate School of Comprehensive Human Sciences, Center for Tsukuba Advanced Research Alliance, and ERATO Environmental Research Project, University of Tsukuba, 1-1-1 Tennoudai, Tsukuba 305-8577, Japan.
authors.forename: Naoko
authors.initials: N
authors.lastname: Minegishi
authors.forename: Norio
authors.initials: N
authors.lastname: Suzuki
authors.forename: Yukie
authors.initials: Y
authors.lastname: Kawatani
authors.forename: Ritsuko
authors.initials: R
authors.lastname: Shimizu
authors.forename: Masayuki
authors.initials: M
authors.lastname: Yamamoto
mesh_terms: D000111:Acetylcysteine / Q000031:analogs & derivatives / Q000494:pharmacology; D000818:Animals; D002478:Cells, Cultured / Q000187:drug effects / Q000528:radiation effects; D003513:Cycloheximide / Q000494:pharmacology; D015853:Cysteine Proteinase Inhibitors / Q000494:pharmacology; D004268:DNA-Binding Proteins / Q000235:genetics / Q000378:metabolism*; D050989:GATA2 Transcription Factor; D017353:Gene Deletion; D005786:Gene Expression Regulation / Q000187:drug effects / Q000528:radiation effects; D006207:Half-Life; D006801:Humans; D007942:Leukemia, Experimental / Q000378:metabolism* / Q000473:pathology; D007976:Leupeptins / Q000494:pharmacology; D051379:Mice; D009154:Mutation; D009447:Neuroblastoma / Q000378:metabolism* / Q000473:pathology; D046988:Proteasome Endopeptidase Complex / Q000378:metabolism*; D011993:Recombinant Fusion Proteins / Q000235:genetics / Q000378:metabolism; D012441:Saccharomyces cerevisiae; D029701:Saccharomyces cerevisiae Proteins; D014157:Transcription Factors / Q000235:genetics / Q000378:metabolism*; D015533:Transcriptional Activation; D014452:Ubiquitins / Q000378:metabolism*; D014466:Ultraviolet Rays
chemical_list: D015853:Cysteine Proteinase Inhibitors; D004268:DNA-Binding Proteins; C052130:GAL4 protein, S cerevisiae; D050989:GATA2 Transcription Factor; C494711:GATA2 protein, human; C494712:Gata2 protein, mouse; D007976:Leupeptins; D011993:Recombinant Fusion Proteins; D029701:Saccharomyces cerevisiae Proteins; D014157:Transcription Factors; D014452:Ubiquitins; C067713:lactacystin; D003513:Cycloheximide; D046988:Proteasome Endopeptidase Complex; C072553:benzyloxycarbonylleucyl-leucyl-leucine aldehyde; D000111:Acetylcysteine