Regulation of Drosophila hypoxia-inducible factor (HIF) activity in SL2 cells: Identification of a hypoxia-induced variant isoform of the HIFα homolog gene similar
Although hypoxia-inducible factor-α (HIFα) subunit-specific hydroxylation and proteolytic breakdown explain the binary switch between the presence (hypoxia) and absence (normoxia) of HIFs, little is known of the mechanisms that fine-tune HIF activity under constant, rather than changing, oxygen tens...
Guardado en:
| Autor principal: | |
|---|---|
| Publicado: |
2004
|
| Materias: | |
| Acceso en línea: | https://bibliotecadigital.exactas.uba.ar/collection/paper/document/paper_00219258_v279_n34_p36048_Gorr http://hdl.handle.net/20.500.12110/paper_00219258_v279_n34_p36048_Gorr |
| Aporte de: |
| id |
paper:paper_00219258_v279_n34_p36048_Gorr |
|---|---|
| record_format |
dspace |
| spelling |
paper:paper_00219258_v279_n34_p36048_Gorr2023-06-08T14:43:25Z Regulation of Drosophila hypoxia-inducible factor (HIF) activity in SL2 cells: Identification of a hypoxia-induced variant isoform of the HIFα homolog gene similar Wappner, Pablo Amino acids Chelation Genes Hydroxylation Iron Iron chelation Sima genes Cell culture amino acid cobalt complementary DNA deferoxamine erythropoietin helix loop helix protein hypoxia inducible factor 1alpha iron luciferase messenger RNA metal oxygen PAS protein protein Tango RNA Sima protein unclassified drug animal cell article controlled study Drosophila gene overexpression genetic transfection hydroxylation hypoxia hypoxia response element molecular cloning nonhuman Northern blotting open reading frame oxygen tension priority journal protein degradation protein localization reporter gene reverse transcription polymerase chain reaction RNA isolation signal transduction transcription regulation untranslated region Western blotting Amino Acid Sequence Animals Aryl Hydrocarbon Receptor Nuclear Translocator Carrier Proteins Cell Hypoxia Cell Line DNA-Binding Proteins Drosophila Drosophila Proteins Gene Expression Regulation Humans Hypoxia-Inducible Factor 1, alpha Subunit Molecular Sequence Data Sequence Homology Signal Transduction Transcription Factors Animalia Although hypoxia-inducible factor-α (HIFα) subunit-specific hydroxylation and proteolytic breakdown explain the binary switch between the presence (hypoxia) and absence (normoxia) of HIFs, little is known of the mechanisms that fine-tune HIF activity under constant, rather than changing, oxygen tensions. Here, we report that the Drosophila HIFα homolog, the basic helix-loop-helix/PAS protein Sima (Similar), in hypoxic cultures of SL2 cells is expressed in full-length (fl) and splice variant (sv) isoforms. The following evidence supports the role of flSima as functional HIFα and the role of SL2 HIF as a transcriptional activator or suppressor. The pO2 dependence of Sima abundance matched that of HIF activity. HIF-dependent changes in candidate target gene expression were detected through variously effective stimuli: hypoxia (strong) > iron chelation, e.g. desferrioxamine (moderate) ≪ transition metals, e.g. cobalt ≃ normoxia (ineffective). Sima overexpression augmented hypoxic induction or suppression of different targets. In addition to the full-length exon 1-12 transcript yielding the 1510-amino acid HIFα homolog, the sima gene also expressed, specifically under hypoxia, an exon 1-7/12 splice variant, which translated into a 426-amino acid Sima truncation termed svSima. svSima contains basic helix-loop-helix and PAS sequences identical to those of flSima, but, because of deletion of exons 8-11, lacks the oxygen-dependent degradation domain and nuclear localization signals. Overexpressed svSima failed to transactivate reporter genes. However, it attenuated HIF (Sima-Tango)-stimulated reporter expression in a dose-dependent manner. Thus, svSima has the potential to regulate Drosophila HIF function under steady and hypoxic pO2 by creating a cytosolic sink for the Sima partner protein Tango. Fil:Wappner, P. Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales; Argentina. 2004 https://bibliotecadigital.exactas.uba.ar/collection/paper/document/paper_00219258_v279_n34_p36048_Gorr http://hdl.handle.net/20.500.12110/paper_00219258_v279_n34_p36048_Gorr |
| institution |
Universidad de Buenos Aires |
| institution_str |
I-28 |
| repository_str |
R-134 |
| collection |
Biblioteca Digital - Facultad de Ciencias Exactas y Naturales (UBA) |
| topic |
Amino acids Chelation Genes Hydroxylation Iron Iron chelation Sima genes Cell culture amino acid cobalt complementary DNA deferoxamine erythropoietin helix loop helix protein hypoxia inducible factor 1alpha iron luciferase messenger RNA metal oxygen PAS protein protein Tango RNA Sima protein unclassified drug animal cell article controlled study Drosophila gene overexpression genetic transfection hydroxylation hypoxia hypoxia response element molecular cloning nonhuman Northern blotting open reading frame oxygen tension priority journal protein degradation protein localization reporter gene reverse transcription polymerase chain reaction RNA isolation signal transduction transcription regulation untranslated region Western blotting Amino Acid Sequence Animals Aryl Hydrocarbon Receptor Nuclear Translocator Carrier Proteins Cell Hypoxia Cell Line DNA-Binding Proteins Drosophila Drosophila Proteins Gene Expression Regulation Humans Hypoxia-Inducible Factor 1, alpha Subunit Molecular Sequence Data Sequence Homology Signal Transduction Transcription Factors Animalia |
| spellingShingle |
Amino acids Chelation Genes Hydroxylation Iron Iron chelation Sima genes Cell culture amino acid cobalt complementary DNA deferoxamine erythropoietin helix loop helix protein hypoxia inducible factor 1alpha iron luciferase messenger RNA metal oxygen PAS protein protein Tango RNA Sima protein unclassified drug animal cell article controlled study Drosophila gene overexpression genetic transfection hydroxylation hypoxia hypoxia response element molecular cloning nonhuman Northern blotting open reading frame oxygen tension priority journal protein degradation protein localization reporter gene reverse transcription polymerase chain reaction RNA isolation signal transduction transcription regulation untranslated region Western blotting Amino Acid Sequence Animals Aryl Hydrocarbon Receptor Nuclear Translocator Carrier Proteins Cell Hypoxia Cell Line DNA-Binding Proteins Drosophila Drosophila Proteins Gene Expression Regulation Humans Hypoxia-Inducible Factor 1, alpha Subunit Molecular Sequence Data Sequence Homology Signal Transduction Transcription Factors Animalia Wappner, Pablo Regulation of Drosophila hypoxia-inducible factor (HIF) activity in SL2 cells: Identification of a hypoxia-induced variant isoform of the HIFα homolog gene similar |
| topic_facet |
Amino acids Chelation Genes Hydroxylation Iron Iron chelation Sima genes Cell culture amino acid cobalt complementary DNA deferoxamine erythropoietin helix loop helix protein hypoxia inducible factor 1alpha iron luciferase messenger RNA metal oxygen PAS protein protein Tango RNA Sima protein unclassified drug animal cell article controlled study Drosophila gene overexpression genetic transfection hydroxylation hypoxia hypoxia response element molecular cloning nonhuman Northern blotting open reading frame oxygen tension priority journal protein degradation protein localization reporter gene reverse transcription polymerase chain reaction RNA isolation signal transduction transcription regulation untranslated region Western blotting Amino Acid Sequence Animals Aryl Hydrocarbon Receptor Nuclear Translocator Carrier Proteins Cell Hypoxia Cell Line DNA-Binding Proteins Drosophila Drosophila Proteins Gene Expression Regulation Humans Hypoxia-Inducible Factor 1, alpha Subunit Molecular Sequence Data Sequence Homology Signal Transduction Transcription Factors Animalia |
| description |
Although hypoxia-inducible factor-α (HIFα) subunit-specific hydroxylation and proteolytic breakdown explain the binary switch between the presence (hypoxia) and absence (normoxia) of HIFs, little is known of the mechanisms that fine-tune HIF activity under constant, rather than changing, oxygen tensions. Here, we report that the Drosophila HIFα homolog, the basic helix-loop-helix/PAS protein Sima (Similar), in hypoxic cultures of SL2 cells is expressed in full-length (fl) and splice variant (sv) isoforms. The following evidence supports the role of flSima as functional HIFα and the role of SL2 HIF as a transcriptional activator or suppressor. The pO2 dependence of Sima abundance matched that of HIF activity. HIF-dependent changes in candidate target gene expression were detected through variously effective stimuli: hypoxia (strong) > iron chelation, e.g. desferrioxamine (moderate) ≪ transition metals, e.g. cobalt ≃ normoxia (ineffective). Sima overexpression augmented hypoxic induction or suppression of different targets. In addition to the full-length exon 1-12 transcript yielding the 1510-amino acid HIFα homolog, the sima gene also expressed, specifically under hypoxia, an exon 1-7/12 splice variant, which translated into a 426-amino acid Sima truncation termed svSima. svSima contains basic helix-loop-helix and PAS sequences identical to those of flSima, but, because of deletion of exons 8-11, lacks the oxygen-dependent degradation domain and nuclear localization signals. Overexpressed svSima failed to transactivate reporter genes. However, it attenuated HIF (Sima-Tango)-stimulated reporter expression in a dose-dependent manner. Thus, svSima has the potential to regulate Drosophila HIF function under steady and hypoxic pO2 by creating a cytosolic sink for the Sima partner protein Tango. |
| author |
Wappner, Pablo |
| author_facet |
Wappner, Pablo |
| author_sort |
Wappner, Pablo |
| title |
Regulation of Drosophila hypoxia-inducible factor (HIF) activity in SL2 cells: Identification of a hypoxia-induced variant isoform of the HIFα homolog gene similar |
| title_short |
Regulation of Drosophila hypoxia-inducible factor (HIF) activity in SL2 cells: Identification of a hypoxia-induced variant isoform of the HIFα homolog gene similar |
| title_full |
Regulation of Drosophila hypoxia-inducible factor (HIF) activity in SL2 cells: Identification of a hypoxia-induced variant isoform of the HIFα homolog gene similar |
| title_fullStr |
Regulation of Drosophila hypoxia-inducible factor (HIF) activity in SL2 cells: Identification of a hypoxia-induced variant isoform of the HIFα homolog gene similar |
| title_full_unstemmed |
Regulation of Drosophila hypoxia-inducible factor (HIF) activity in SL2 cells: Identification of a hypoxia-induced variant isoform of the HIFα homolog gene similar |
| title_sort |
regulation of drosophila hypoxia-inducible factor (hif) activity in sl2 cells: identification of a hypoxia-induced variant isoform of the hifα homolog gene similar |
| publishDate |
2004 |
| url |
https://bibliotecadigital.exactas.uba.ar/collection/paper/document/paper_00219258_v279_n34_p36048_Gorr http://hdl.handle.net/20.500.12110/paper_00219258_v279_n34_p36048_Gorr |
| work_keys_str_mv |
AT wappnerpablo regulationofdrosophilahypoxiainduciblefactorhifactivityinsl2cellsidentificationofahypoxiainducedvariantisoformofthehifahomologgenesimilar |
| _version_ |
1768545723662467072 |