A promoter mutation in the erythroid-specific 5-aminolevulinate synthase (ALAS2) gene causes X-linked sideroblastic anemia

Bekri, Soumeya; May, Alison; Cotter, Philip D.; Al‐Sabah, Ayesha; Guo, Xiaojun; Masters, Gillian S.; Bishop, David F.

doi:10.1182/blood-2002-06-1623

Cited by 45 publications

(24 citation statements)

References 28 publications

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“…31 In this context, it has been reported that the deleted region contained a functionally important element for ALAS2 transcription. 16 Bekri et al reported a C-to-G transversion at nucleotide -206 (c.-258C>G) from the transcription start site in the proximal region of the human ALAS2 gene in patients with XLSA; 24 however, May et al identified this transversion in normal individuals from South Wales at the rate of 0.05, suggesting that this promoter mutation is a polymorphism. 32 In conclusion, we have identified a novel erythroid-specific enhancer in the first intron of the human ALAS2 gene, the enhancer function of which may be directed by GATA1 with other transcription factors, such as EKLF and AP-1 binding proteins.…”

Section: Discussionmentioning

confidence: 99%

“…The human ALAS2 proximal promoter region (g.4820_5115, between -267 and +29 from the transcription start site) 16,24 was cloned into the multiple-cloning site of pGL3basic [referred to as pGL3-AEpro (-267)]. A single DNA fragment (5.2 kbp), carrying the ALAS2 proximal promoter, first exon, first intron and the untranslated region of the second exon, was subcloned into the multiple cloning site of pGL3basic [referred to as pGL3-AEpro(-267)+intron1].…”

Section: Promoter/enhancer Activity Assaysmentioning

confidence: 99%

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Identification of a novel erythroid-specific enhancer for the ALAS2 gene and its loss-of-function mutation which is associated with congenital sideroblastic anemia

et al. 2013

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© F e r r a t a S t o r t i F o u n d a t i o nsequence of primers and probes used in this study are listed in the Online Supplementary Tables. Polymerase chain reaction-based quantitative chromatin immunoprecipitationReal-time PCR-based quantitative chromatin immunoprecipitation (ChIP-qPCR) analysis was conducted essentially as previously described. 22 Electrophoretic mobility shift assayElectrophoretic mobility shift assay (EMSA) was performed using "DIG Gel Shift Kit, 2 nd Generation" (Roche Diagnostics GmbH, Mannheim, Germany), according to the manufacturer's protocol. Sequences of oligonucleotides for probes are indicated by the horizontal bar in the relevant figures. Nuclear extracts were prepared, as described previously, 23 from K562 cells or HEK293 human embryonic kidney cells that were transfected with a GATA1-FLAG fusion protein expression vector or its backbone vector. Promoter/enhancer activity assaysEach target DNA fragment was prepared from genomic DNA from normal volunteers (WT) or patients with CSA (referred to as "GGTA" or "delGATA" in each reporter construct) and was cloned into pGL3basic plasmid (Promega Corporation, Madison, WI, USA). The human ALAS2 proximal promoter region (g.4820_5115, between -267 and +29 from the transcription start site) 16,24 was cloned into the multiple-cloning site of pGL3basic [referred to as pGL3-AEpro (-267)]. A single DNA fragment (5.2 kbp), carrying the ALAS2 proximal promoter, first exon, first intron and the untranslated region of the second exon, was subcloned into the multiple cloning site of pGL3basic [referred to as pGL3-AEpro(-267)+intron1]. A DNA fragment containing the GATA1-binding region in the first intron of the ALAS2 gene (corresponding to g.7488_7960), which was defined by ChIP-seq analysis, 22 is referred to as the ChIP-peak. The length of the WT ChIP-peak is 473 bp. In addition, a 130-bp fragment containing ALAS2int1GATA, the consensus sequence for the GATA1-binding site in the ChIP-peak, is referred to as ChIPmini. Several deletion mutants of ChIPmini were prepared using pGL3-AEpro(-267)+ChIPmini(WT) as a template. The pGL3-TKpro plasmid was constructed by cloning herpes simplex virus thymidine kinase promoter into the multiple cloning site of pGL3basic plasmid. Each reporter vector and pEF-RL25 were introduced into K562 cells or HEK293 cells. Luciferase activity was determined using a dualluciferase reporter system (Promega).Disruption of a GATA binding element causes CSA haematologica | 2014; 99 (2) 253 Figure 1. Identification of a functional GATA1 element in the first intron of the ALAS2 gene. (A) Chromatin immunoprecipitation assay. Fragmented genomic DNA segments were immunoprecipitated with anti-GATA1 antibody or control IgG, and then precipitated fragments were quantified using real-time PCR as described in the Online Supplementary Methods. PC or NC indicates positive control or negative control, respectively, for the ChIP assay using anti-GATA1 in K562 cells. 22 One GATA element is present in the proximal promoter region and ...

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Section: Discussionmentioning

confidence: 99%

Section: Promoter/enhancer Activity Assaysmentioning

confidence: 99%

Identification of a novel erythroid-specific enhancer for the ALAS2 gene and its loss-of-function mutation which is associated with congenital sideroblastic anemia

et al. 2013

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“…Characterization of the promoter region of the human ALAS2 gene revealed several putative binding sites for the ery- throid-specific transcription factors GATA-1 and NF-E2. In addition, as discussed before, the IRE motif of ALAS2 mRNA in the 5´-protein noncoding region is involved in regulating the translation of mRNA to protein (Bekri et al 2003). Mice lacking ALAS2 died in the embryonic stage (Nakajima et al 1999).…”

Section: Biosynthesis and Regulation Of Heme Metabolism In Mitochondriamentioning

confidence: 99%

“…In disorders of heme biosynthesis including anemia with ALAS2-deficient, ring-sideroblasts and hemosiderin characteristics of iron accumulation appear (May and Bishop 1998;Bekri et al 2003). These phenotypes are distinguished from iron-deficient anemia.…”

Section: Functions and Regulation Of Iron Metabolism In Mitochondriamentioning

confidence: 99%

Aquisition, Mobilization and Utilization of Cellular Iron and Heme: Endless Findings and Growing Evidence of Tight Regulation

Taketani

2005

Tohoku J. Exp. Med.

100

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Iron is fastidiously utilized by living cells, since it is an essential element, but is toxic in excess. Cells take up iron via a transferrin-transferrin receptor-dependent endocytotic process. The iron thus taken up is used for essential biological functions including oxygen transport, electron transfer, and DNA synthesis. The intracellular level of iron is tightly controlled, through regulation of the cellular uptake of iron and the sequestering of low molecular labile iron into the storage protein ferritin. The known proteins of iron transport and storage, transferrin, transferrin receptor and ferritin, have been recently linked with a number of newly identified proteins that are responsible for inherited diseases of iron metabolisms and play critical roles in the maintenance of iron homeostasis. These proteins are involved in regulation of intracellular levels of iron, iron transport, and heme transport and the oxygen-dependent regulation of gene expression. On the other hand, most iron is transported into mitochondria and immediately used for the biosynthesis of heme in erythroid cells. The heme biosynthesis in mitochondria is coupled with the supply of iron, and the heme, exported from mitochondria, is utilized as prosthetic groups of hemeproteins. Furthermore, non-erythroid and erythroid cells possess the different regulatory systems for the biosynthesis of heme; iron positively regulates the biosynthesis in erythroid cells while heme negatively regulates it in non-erythroid cells. Because of the toxicity and insolubility of heme, the intracellular level of uncommitted heme is maintained at a low concentration (< 10 -9 M). The influx and efflux of heme also help to prevent cytotoxicity. Finally, heme-binding transcriptional factors such as Bach1 and NPAS2 regulate the transcription of several genes involved in the synthesis and degradation of heme-hemeproteins. The discovery of new molecules related to disorders of iron and heme metabolism is ascribable to a complete mechanistic understanding of the cellular network of iron homeostasis. The network of interactions that link iron and heme metabolisms with functions of cellular regulation involving oxidative stress and inflammations contributes to new insights into clinical aspects of disorders.

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“…f Variants with a frequency o1% are de¢ned as rare. mutations cannot be excluded since null mutations in promoters have already been reported in other diseases [Bekri et al, 2003]. Regulatory variants, defined as variants upstream of the start codon, including the 5 0 region, 5 0 UTR and intron 1, and variants in the 3 0 UTR, were reported.…”

Section: Variants With Unclear Pathogenic Signi¢cancementioning

confidence: 99%

Granulin mutations associated with frontotemporal lobar degeneration and related disorders: An update

2008

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Communicated by Mark H. PaalmanMutations in the gene encoding granulin (HUGO gene symbol GRN, also referred to as progranulin, PGRN), located at chromosome 17q21, were recently linked to tau-negative ubiquitin-positive frontotemporal lobar degeneration (FTLDU). Since then, 63 heterozygous mutations were identified in 163 families worldwide, all leading to loss of functional GRN, implicating a haploinsufficiency mechanism. Together, these mutations explained 5 to 10% of FTLD. The high mutation frequency, however, might still be an underestimation because not all patient samples were examined for all types of loss-of-function mutations and because several variants, including missense mutations, have a yet uncertain pathogenic significance. Although the complete phenotypic spectrum associated with GRN mutations is not yet fully characterized, it was shown that it is highly heterogeneous, suggesting the influence of modifying factors. A role of GRN in neuronal survival was suggested but the exact mechanism by which neurodegeneration and deposition of pathologic brain inclusions occur still has to be clarified. Hum Mutat 29(12), [1373][1374][1375][1376][1377][1378][1379][1380][1381][1382][1383][1384][1385][1386] 2008.

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A promoter mutation in the erythroid-specific 5-aminolevulinate synthase (ALAS2) gene causes X-linked sideroblastic anemia

Cited by 45 publications

References 28 publications

Identification of a novel erythroid-specific enhancer for the ALAS2 gene and its loss-of-function mutation which is associated with congenital sideroblastic anemia

Identification of a novel erythroid-specific enhancer for the ALAS2 gene and its loss-of-function mutation which is associated with congenital sideroblastic anemia

Aquisition, Mobilization and Utilization of Cellular Iron and Heme: Endless Findings and Growing Evidence of Tight Regulation

Granulin mutations associated with frontotemporal lobar degeneration and related disorders: An update

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