4h6j
From Proteopedia
Identification of Cys 255 in HIF-1 as a novel site for development of covalent inhibitors of HIF-1 /ARNT PasB domain protein-protein interaction.
Structural highlights
Function[HIF1A_HUMAN] Functions as a master transcriptional regulator of the adaptive response to hypoxia. Under hypoxic conditions, activates the transcription of over 40 genes, including erythropoietin, glucose transporters, glycolytic enzymes, vascular endothelial growth factor, HILPDA, and other genes whose protein products increase oxygen delivery or facilitate metabolic adaptation to hypoxia. Plays an essential role in embryonic vascularization, tumor angiogenesis and pathophysiology of ischemic disease. Binds to core DNA sequence 5'-[AG]CGTG-3' within the hypoxia response element (HRE) of target gene promoters. Activation requires recruitment of transcriptional coactivators such as CREBPB and EP300. Activity is enhanced by interaction with both, NCOA1 or NCOA2. Interaction with redox regulatory protein APEX seems to activate CTAD and potentiates activation by NCOA1 and CREBBP. Involved in the axonal distribution and transport of mitochondria in neurons during hypoxia.[1] [2] [3] [4] [5] [6] [7] [8] [9] [ARNT_HUMAN] Required for activity of the Ah (dioxin) receptor. This protein is required for the ligand-binding subunit to translocate from the cytosol to the nucleus after ligand binding. The complex then initiates transcription of genes involved in the activation of PAH procarcinogens. The heterodimer with HIF1A or EPAS1/HIF2A functions as a transcriptional regulator of the adaptive response to hypoxia. Publication Abstract from PubMedThe heterodimer HIF-1alpha (hypoxia inducible factor)/HIF-beta (also known as ARNT-aryl hydrocarbon nuclear translocator) is a key mediator of cellular response to hypoxia. The interaction between these monomer units can be modified by the action of small molecules in the binding interface between their C-terminal heterodimerization (PasB) domains. Taking advantage of the presence of several cysteine residues located in the allosteric cavity of HIF-1alpha PasB domain, we applied a cysteine-based reactomics "hotspot identification" strategy to locate regions of HIF-1alpha PasB domain critical for its interaction with ARNT. COMPOUND 5 was identified using a mass spectrometry-based primary screening strategy and was shown to react specifically with Cys255 of the HIF-1alpha PasB domain. Biophysical characterization of the interaction between PasB domains of HIF-1alpha and ARNT revealed that covalent binding of COMPOUND 5 to Cys255 reduced binding affinity between HIF-1alpha and ARNT PasB domains approximately 10-fold. Detailed NMR structural analysis of HIF-1alpha-PasB-COMPOUND 5 conjugate showed significant local conformation changes in the HIF-1alpha associated with key residues involved in the HIF-1alpha/ARNT PasB domain interaction as revealed by the crystal structure of the HIF-1alpha/ARNT PasB heterodimer. Our screening strategy could be applied to other targets to identify pockets surrounding reactive cysteines suitable for development of small molecule modulators of protein function. Identification of Cys255 in HIF-1alpha as a novel site for development of covalent inhibitors of HIF-1alpha/ARNT PasB domain protein-protein interaction.,Cardoso R, Love R, Nilsson CL, Bergqvist S, Nowlin D, Yan J, Liu KK, Zhu J, Chen P, Deng YL, Dyson HJ, Greig MJ, Brooun A Protein Sci. 2012 Dec;21(12):1885-96. doi: 10.1002/pro.2172. Epub 2012 Nov 9. PMID:23033253[10] From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine. See AlsoReferences
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Categories: Homo sapiens | Bergqvist, S | Brooun, A | Cardoso, R | Chen, P | Deng, Y L | Dyson, H J | Greig, M J | Liu, K | Love, R A | Nilsson, C | Nowlin, D | Yan, J | Zhu, J | Arnt | Heterodimer | Hypoxia inducible factor | Pas domain | Transcription | Transcription factor
