Expression of N-WASP is regulated by HiF1α through the hypoxia response element in the N-WASP promoter

Cancer cell migration and invasion involves temporal and spatial regulation of actin cytoskeleton reorganization, which is regulated by the WASP family of proteins such as N-WASP (Neural- Wiskott Aldrich Syndrome Protein). We have previously shown that expression of N-WASP was increased under hypoxi...

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Main Authors: Salvi, Amrita, Thanabalu, Thirumaran
Other Authors: School of Biological Sciences
Format: Article
Language:English
Published: 2017
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Online Access:https://hdl.handle.net/10356/83924
http://hdl.handle.net/10220/42886
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Institution: Nanyang Technological University
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spelling sg-ntu-dr.10356-839242023-02-28T17:03:50Z Expression of N-WASP is regulated by HiF1α through the hypoxia response element in the N-WASP promoter Salvi, Amrita Thanabalu, Thirumaran School of Biological Sciences N-WASP Hypoxia Cancer cell migration and invasion involves temporal and spatial regulation of actin cytoskeleton reorganization, which is regulated by the WASP family of proteins such as N-WASP (Neural- Wiskott Aldrich Syndrome Protein). We have previously shown that expression of N-WASP was increased under hypoxic conditions. In order to characterize the regulation of N-WASP expression, we constructed an N-WASP promoter driven GFP reporter construct, N-WASPpro-GFP. Transfection of N-WASPpro-GFP construct and plasmid expressing HiF1α (Hypoxia Inducible factor 1α) enhanced the expression of GFP suggesting that increased expression of N-WASP under hypoxic conditions is mediated by HiF1α. Sequence analysis of the N-WASP promoter revealed the presence of two hypoxia response elements (HREs) characterized by the consensus sequence 5′-GCGTG-3′ at -132 bp(HRE1) and at -662 bp(HRE2) relative to transcription start site (TSS). Site-directed mutagenesis of HRE1(-132) but not HRE2(-662) abolished the HiF1α induced activation of N-WASP promoter. Similarly ChIP assay demonstrated that HiF1α bound to HRE1(-132) but not HRE2(-662) under hypoxic condition. MDA-MB-231 cells but not MDA-MB-231KD cells treated with hypoxia mimicking agent, DMOG showed enhanced gelatin degradation. Similarly MDA-MB-231KD(N-WASPpro-N-WASPR) cells expressing N-WASPR under the transcriptional regulation of WT N-WASPpro but not MDA-MB-231KD(N-WASPproHRE1-N-WASPR) cells expressing N-WASPR under the transcriptional regulation of N-WASPproHRE1 showed enhanced gelatin degradation when treated with DMOG. Thus indicating the importance of N-WASP in hypoxia induced invadopodia formation. Thus, our data demonstrates that hypoxia-induced activation of N-WASP expression is mediated by interaction of HiF1α with the HRE1(-132) and explains the role of N-WASP in hypoxia induced invadopodia formation. MOE (Min. of Education, S’pore) Published version 2017-07-17T07:00:17Z 2019-12-06T15:34:44Z 2017-07-17T07:00:17Z 2019-12-06T15:34:44Z 2016 Journal Article Salvi, A., & Thanabalu, T. (2017). Expression of N-WASP is regulated by HiF1α through the hypoxia response element in the N-WASP promoter. Biochemistry and Biophysics Reports, 9, 13-21. https://hdl.handle.net/10356/83924 http://hdl.handle.net/10220/42886 10.1016/j.bbrep.2016.10.010 en Biochemistry and Biophysics Reports © 2016 The Author(s). Published by Elsevier B.V. This is an open access article under the CC BY-NC-ND license (http://creativecommons.org/licenses/BY-NC-ND/4.0/). 9 p. application/pdf
institution Nanyang Technological University
building NTU Library
continent Asia
country Singapore
Singapore
content_provider NTU Library
collection DR-NTU
language English
topic N-WASP
Hypoxia
spellingShingle N-WASP
Hypoxia
Salvi, Amrita
Thanabalu, Thirumaran
Expression of N-WASP is regulated by HiF1α through the hypoxia response element in the N-WASP promoter
description Cancer cell migration and invasion involves temporal and spatial regulation of actin cytoskeleton reorganization, which is regulated by the WASP family of proteins such as N-WASP (Neural- Wiskott Aldrich Syndrome Protein). We have previously shown that expression of N-WASP was increased under hypoxic conditions. In order to characterize the regulation of N-WASP expression, we constructed an N-WASP promoter driven GFP reporter construct, N-WASPpro-GFP. Transfection of N-WASPpro-GFP construct and plasmid expressing HiF1α (Hypoxia Inducible factor 1α) enhanced the expression of GFP suggesting that increased expression of N-WASP under hypoxic conditions is mediated by HiF1α. Sequence analysis of the N-WASP promoter revealed the presence of two hypoxia response elements (HREs) characterized by the consensus sequence 5′-GCGTG-3′ at -132 bp(HRE1) and at -662 bp(HRE2) relative to transcription start site (TSS). Site-directed mutagenesis of HRE1(-132) but not HRE2(-662) abolished the HiF1α induced activation of N-WASP promoter. Similarly ChIP assay demonstrated that HiF1α bound to HRE1(-132) but not HRE2(-662) under hypoxic condition. MDA-MB-231 cells but not MDA-MB-231KD cells treated with hypoxia mimicking agent, DMOG showed enhanced gelatin degradation. Similarly MDA-MB-231KD(N-WASPpro-N-WASPR) cells expressing N-WASPR under the transcriptional regulation of WT N-WASPpro but not MDA-MB-231KD(N-WASPproHRE1-N-WASPR) cells expressing N-WASPR under the transcriptional regulation of N-WASPproHRE1 showed enhanced gelatin degradation when treated with DMOG. Thus indicating the importance of N-WASP in hypoxia induced invadopodia formation. Thus, our data demonstrates that hypoxia-induced activation of N-WASP expression is mediated by interaction of HiF1α with the HRE1(-132) and explains the role of N-WASP in hypoxia induced invadopodia formation.
author2 School of Biological Sciences
author_facet School of Biological Sciences
Salvi, Amrita
Thanabalu, Thirumaran
format Article
author Salvi, Amrita
Thanabalu, Thirumaran
author_sort Salvi, Amrita
title Expression of N-WASP is regulated by HiF1α through the hypoxia response element in the N-WASP promoter
title_short Expression of N-WASP is regulated by HiF1α through the hypoxia response element in the N-WASP promoter
title_full Expression of N-WASP is regulated by HiF1α through the hypoxia response element in the N-WASP promoter
title_fullStr Expression of N-WASP is regulated by HiF1α through the hypoxia response element in the N-WASP promoter
title_full_unstemmed Expression of N-WASP is regulated by HiF1α through the hypoxia response element in the N-WASP promoter
title_sort expression of n-wasp is regulated by hif1α through the hypoxia response element in the n-wasp promoter
publishDate 2017
url https://hdl.handle.net/10356/83924
http://hdl.handle.net/10220/42886
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