scholarly journals Hypoxia-inducible factor 1 is a basic-helix-loop-helix-PAS heterodimer regulated by cellular O2 tension.

1995 ◽  
Vol 92 (12) ◽  
pp. 5510-5514 ◽  
Author(s):  
G. L. Wang ◽  
B. H. Jiang ◽  
E. A. Rue ◽  
G. L. Semenza
Keyword(s):  
Hypoxia Inducible Factor ◽  
Hypoxia Inducible Factor 1 ◽  
Basic Helix Loop Helix ◽  
Helix Loop Helix

Molecular characteristics and induction profiles of hypoxia-inducible factor-1αand other basic helix–loop–helix and Per–Arnt–Sim domain-containing proteins identified in a carcinogenic liver flukeClonorchis sinensis

Parasitology ◽  
2018 ◽  
Vol 146 (2) ◽  
pp. 176-186
Author(s):  
Seon-Hee Kim ◽  
Gyu-Seok Oh ◽  
Woon-Mok Sohn ◽  
Kihyun Lee ◽  
Hyun-Jong Yang ◽  
...  
Keyword(s):  
Nitric Oxide ◽  
Clonorchis Sinensis ◽  
Hypoxia Inducible Factor ◽  
Hypoxic Condition ◽  
Molecular Structures ◽  
Molecular Characteristics ◽  
Basic Helix Loop Helix ◽  
Helix Loop Helix ◽  
Aryl Hydrocarbon ◽  
Oxygen Condition

AbstractClonorchis sinensis(C. sinensis), a trematode parasite that invades the hypoxic hepatobiliary tract of vertebrate hosts requires a considerable amount of oxygen for its sexual reproduction and energy metabolism. However, little is known regarding the molecular mechanism ofC. sinensisinvolved in the adaptation to the hypoxic environments. In this study, we investigated the molecular structures and induction patterns of hypoxia-inducible factor-1α(HIF-1α) and other basic helix–loop–helix and Per–Arnt–Sim (bHLH–PAS) domain-containing proteins such as HIF-1β, single-minded protein and aryl hydrocarbon receptor, which might prompt adaptive response to hypoxia, inC. sinensis. These proteins possessed various bHLH–PAS family-specific domains. Expression ofC. sinensis HIF-1α(CsHIF-1α) was highly induced in worms which were either exposed to a hypoxic condition or co-incubated with human cholangiocytes. In addition to oxygen, nitric oxide and nitrite affected theCsHIF-1αexpression depending on the surrounding oxygen concentration. Treatment using a prolyl hydroxylase-domain protein inhibitor under 20%-oxygen condition resulted in an increase in the CsHIF-1αlevel. Conversely, the otherbHLH–PASgenes were less responsive to these exogenous stimuli. We suggest that nitrite and nitric oxide, as well as oxygen, coordinately involve in the regulation of HIF-1αexpression to adapt to the hypoxic host environments inC. sinensis.

scholarly journals Induction of Endothelial PAS Domain Protein-1 by Hypoxia: Characterization and Comparison With Hypoxia-Inducible Factor-1α

Blood ◽  
1998 ◽  
Vol 92 (7) ◽  
pp. 2260-2268 ◽  
Author(s):  
M.S. Wiesener ◽  
H. Turley ◽  
W.E. Allen ◽  
C. Willam ◽  
K.-U. Eckardt ◽  
...  
Keyword(s):  
Mutant Cell ◽  
Hypoxia Inducible Factor ◽  
Cell Types ◽  
Pas Domain ◽  
Functional Studies ◽  
Hypoxia Inducible Factor 1 ◽  
Helix Loop Helix ◽  
Aryl Hydrocarbon ◽  
Domain Protein ◽  
Different Cell Types

Abstract Hypoxia results in adaptive changes in the transcription of a range of genes including erythropoietin. An important mediator is hypoxia-inducible factor-1 (HIF-1), a DNA binding complex shown to contain at least two basic helix-loop-helix PAS-domain (bHLH-PAS) proteins, HIF-1α and aryl hydrocarbon nuclear receptor translocator (ARNT). In response to hypoxia, HIF-1α is activated and accumulates rapidly in the cell. Endothelial PAS domain protein 1 (EPAS-1) is a recently identified bHLH-PAS protein with 48% identity to HIF-1α, raising the question of its role in responses to hypoxia. We developed specific antibodies and studied expression and regulation of EPAS-1 mRNA and protein across a range of human cell lines. EPAS-1 was widely expressed, and strongly induced by hypoxia at the level of protein but not mRNA. Comparison of the effect of a range of activating and inhibitory stimuli showed striking similarities in the EPAS-1 and HIF-1α responses. Although major differences were observed in the abundance of EPAS-1 and HIF-1α in different cell types, differences in the inducible response were subtle with EPAS-1 protein being slightly more evident in normoxic and mildly hypoxic cells. Functional studies in a mutant cell line (Ka13) expressing neither HIF-1α nor EPAS-1 confirmed that both proteins interact with hypoxically responsive targets, but suggest target specificity with greater EPAS-1 transactivation (relative to HIF-1α transactivation) of the VEGF promoter than the LDH-A promoter.

The Potential Role of Hypoxia-inducible Factor-1 in the Progression and Therapy of Central Nervous System Diseases

2021 ◽  
Vol 19 ◽  
Author(s):  
Hongxiu Chen ◽  
Di Ma ◽  
Feixue Yue ◽  
Yajie Qi ◽  
Manman Dou ◽  
...  
Keyword(s):  
Central Nervous System ◽  
Nervous System ◽  
Target Genes ◽  
Hypoxia Inducible Factor ◽  
Hypoxia Inducible Factor 1 ◽  
Helix Loop Helix ◽  
Hypoxic Brain Injury ◽  
Hypoxic Brain ◽  
Structural Subunit ◽  
Oxygen Sensitive

: Hypoxia-inducible factor-1 (HIF-1) is a heterodimer protein composed of an oxygen-regulated functional subunit, HIF-1α, and a structural subunit, HIF-1β, belonging to the basic helix-loop-helix family. Strict regulation of HIF-1 protein stability and subsequent transcriptional activity involves various molecular interactions and is primarily controlled by post-transcriptional modifications. Hypoxia, owing to impaired cerebral blood flow, has been implicated in a range of central nervous system (CNS) diseases by exerting a deleterious effect on brain function. As a master oxygen-sensitive transcription regulator, HIF-1 is responsible for upregulating a broad spectrum of target genes involved in glucose metabolism, angiogenesis, and erythropoiesis to generate the adaptive response to avoid or minimize hypoxic brain injury. However, prolonged, severe oxygen deprivation may directly contribute to the role-conversion of HIF-1, namely. From neuroprotection to the promotion of cell death. Currently, an increasing number of studies support the fact HIF-1 is involved in a variety of CNS-related diseases, such as intracranial atherosclerosis, stroke, and neurodegenerative diseases. This review article chiefly focuses on the effect of HIF-1 on the pathogenesis and mechanism of progression of numerous CNS-related disorders by mediating the expression of various downstream genes and extensive biological functional events. It presents robust evidence that HIF-1 may represent a potential therapeutic target for CNS-related diseases.

scholarly journals Control of the Hypoxic Response in Drosophila melanogaster by the Basic Helix-Loop-Helix PAS Protein Similar

2002 ◽  
Vol 22 (19) ◽  
pp. 6842-6853 ◽  
Author(s):  
Sofía Lavista-Llanos ◽  
Lázaro Centanin ◽  
Maximiliano Irisarri ◽  
Daniela M. Russo ◽  
Jonathan M. Gleadle ◽  
...  
Keyword(s):  
Drosophila Melanogaster ◽  
Time Course ◽  
Hypoxia Inducible Factor ◽  
Ectopic Expression ◽  
Prolyl Hydroxylase ◽  
Basic Helix Loop Helix ◽  
Helix Loop Helix ◽  
Oxygen Homeostasis ◽  
Multicellular Organisms

ABSTRACT In mammalian systems, the heterodimeric basic helix-loop-helix (bHLH)-PAS transcription hypoxia-inducible factor (HIF) has emerged as the key regulator of responses to hypoxia. Here we define a homologous system in Drosophila melanogaster, and we characterize its activity in vivo during development. By using transcriptional reporters in developing transgenic flies, we show that hypoxia-inducible activity rises to a peak in late embryogenesis and is most pronounced in tracheal cells. We show that the bHLH-PAS proteins Similar (Sima) and Tango (Tgo) function as HIF-α and HIF-β homologues, respectively, and demonstrate a conserved mode of regulation for Sima by oxygen. Sima protein, but not its mRNA, was upregulated in hypoxia. Time course experiments following pulsed ectopic expression demonstrated that Sima is stabilized in hypoxia and that degradation relies on a central domain encompassing amino acids 692 to 863. Continuous ectopic expression overrode Sima degradation, which remained cytoplasmic in normoxia, and translocated to the nucleus only in hypoxia, revealing a second oxygen-regulated activation step. Abrogation of the Drosophila Egl-9 prolyl hydroxylase homologue, CG1114, caused both stabilization and nuclear localization of Sima, indicating a central involvement in both processes. Tight conservation of the HIF/prolyl hydroxylase system in Drosophila provides a new focus for understanding oxygen homeostasis in intact multicellular organisms.

scholarly journals Induction of Endothelial PAS Domain Protein-1 by Hypoxia: Characterization and Comparison With Hypoxia-Inducible Factor-1α

Blood ◽  
1998 ◽  
Vol 92 (7) ◽  
pp. 2260-2268 ◽  
Author(s):  
M.S. Wiesener ◽  
H. Turley ◽  
W.E. Allen ◽  
C. Willam ◽  
K.-U. Eckardt ◽  
...  
Keyword(s):  
Mutant Cell ◽  
Hypoxia Inducible Factor ◽  
Cell Types ◽  
Pas Domain ◽  
Functional Studies ◽  
Hypoxia Inducible Factor 1 ◽  
Helix Loop Helix ◽  
Aryl Hydrocarbon ◽  
Domain Protein ◽  
Different Cell Types

Hypoxia results in adaptive changes in the transcription of a range of genes including erythropoietin. An important mediator is hypoxia-inducible factor-1 (HIF-1), a DNA binding complex shown to contain at least two basic helix-loop-helix PAS-domain (bHLH-PAS) proteins, HIF-1α and aryl hydrocarbon nuclear receptor translocator (ARNT). In response to hypoxia, HIF-1α is activated and accumulates rapidly in the cell. Endothelial PAS domain protein 1 (EPAS-1) is a recently identified bHLH-PAS protein with 48% identity to HIF-1α, raising the question of its role in responses to hypoxia. We developed specific antibodies and studied expression and regulation of EPAS-1 mRNA and protein across a range of human cell lines. EPAS-1 was widely expressed, and strongly induced by hypoxia at the level of protein but not mRNA. Comparison of the effect of a range of activating and inhibitory stimuli showed striking similarities in the EPAS-1 and HIF-1α responses. Although major differences were observed in the abundance of EPAS-1 and HIF-1α in different cell types, differences in the inducible response were subtle with EPAS-1 protein being slightly more evident in normoxic and mildly hypoxic cells. Functional studies in a mutant cell line (Ka13) expressing neither HIF-1α nor EPAS-1 confirmed that both proteins interact with hypoxically responsive targets, but suggest target specificity with greater EPAS-1 transactivation (relative to HIF-1α transactivation) of the VEGF promoter than the LDH-A promoter.

scholarly journals Abnormal Heart Development and Lung Remodeling in Mice Lacking the Hypoxia-Inducible Factor-Related Basic Helix-Loop-Helix PAS Protein NEPAS

2007 ◽  
Vol 28 (4) ◽  
pp. 1285-1297 ◽  
Author(s):  
Toshiharu Yamashita ◽  
Osamu Ohneda ◽  
Masumi Nagano ◽  
Motoyuki Iemitsu ◽  
Yuichi Makino ◽  
...  
Keyword(s):  
Gene Expression ◽  
Endothelial Cells ◽  
Heart Development ◽  
Hypoxia Inducible Factor ◽  
Negative Regulator ◽  
Postnatal Life ◽  
Lung Remodeling ◽  
Basic Helix Loop Helix ◽  
Helix Loop Helix ◽  
Oxygen Homeostasis

ABSTRACT Hypoxia-inducible factors (HIFs) are crucial for oxygen homeostasis during both embryonic development and postnatal life. Here we show that a novel HIF family basic helix-loop-helix (bHLH) PAS (Per-Arnt-Sim) protein, which is expressed predominantly during embryonic and neonatal stages and thereby designated NEPAS (neonatal and embryonic PAS), acts as a negative regulator of HIF-mediated gene expression. NEPAS mRNA is derived from the HIF-3α gene by alternative splicing, replacing the first exon of HIF-3α with that of inhibitory PAS. NEPAS can dimerize with Arnt and exhibits only low levels of transcriptional activity, similar to that of HIF-3α. NEPAS suppressed reporter gene expression driven by HIF-1α and HIF-2α. By generating mice with a targeted disruption of the NEPAS/HIF-3α locus, we found that homozygous mutant mice (NEPAS/HIF-3α− / −) were viable but displayed enlargement of the right ventricle and impaired lung remodeling. The expression of endothelin 1 and platelet-derived growth factor β was increased in the lung endothelial cells of NEPAS/HIF-3α-null mice. These results demonstrate a novel regulatory mechanism in which the activities of HIF-1α and HIF-2α are negatively regulated by NEPAS in endothelial cells, which is pertinent to lung and heart development during the embryonic and neonatal stages.

Vascular adaptations to hypoxia: molecular and cellular mechanisms regulating vascular tone

2007 ◽  
Vol 43 ◽  
pp. 105-120 ◽  
Author(s):  
Michael L. Paffett ◽  
Benjimen R. Walker
Keyword(s):  
Vascular Tone ◽  
Cellular Proliferation ◽  
Hypoxic Pulmonary Vasoconstriction ◽  
Hypoxia Inducible Factor ◽  
Systemic Circulation ◽  
Cellular Mechanisms ◽  
Hypoxia Inducible Factor 1 ◽  
Pulmonary Vasoconstriction ◽  
Adaptive Mechanisms ◽  
Adaptive Processes

Several molecular and cellular adaptive mechanisms to hypoxia exist within the vasculature. Many of these processes involve oxygen sensing which is transduced into mediators of vasoconstriction in the pulmonary circulation and vasodilation in the systemic circulation. A variety of oxygen-responsive pathways, such as HIF (hypoxia-inducible factor)-1 and HOs (haem oxygenases), contribute to the overall adaptive process during hypoxia and are currently an area of intense research. Generation of ROS (reactive oxygen species) may also differentially regulate vascular tone in these circulations. Potential candidates underlying the divergent responses between the systemic and pulmonary circulations may include Nox (NADPH oxidase)-derived ROS and mitochondrial-derived ROS. In addition to alterations in ROS production governing vascular tone in the hypoxic setting, other vascular adaptations are likely to be involved. HPV (hypoxic pulmonary vasoconstriction) and CH (chronic hypoxia)-induced alterations in cellular proliferation, ionic conductances and changes in the contractile apparatus sensitivity to calcium, all occur as adaptive processes within the vasculature.

Sign in / Sign up

Export Citation Format

Share Document