Specific Interaction with Cardiolipin Triggers Functional Activation of Dynamin-Related Protein 1

Dynamin-Related Protein 1 (Drp1), a large GTPase of the dynamin superfamily, is required for mitochondrial fission in healthy and apoptotic cells. Drp1 activation is a complex process that involves translocation from the cytosol to the mitochondrial outer membrane (MOM) and assembly into rings/spirals at the MOM, leading to membrane constriction/division. Similar to dynamins, Drp1 contains GTPase (G), bundle signaling element (BSE) and stalk domains. However, instead of the lipid-interacting Pleckstrin Homology (PH) domain present in the dynamins, Drp1 contains the so-called B insert or variable domain that has been suggested to play an important role in Drp1 regulation. Different proteins have been implicated in Drp1 recruitment to the MOM, although how MOM-localized Drp1 acquires its fully functional status remains poorly understood. We found that Drp1 can interact with pure lipid bilayers enriched in the mitochondrion-specific phospholipid cardiolipin (CL). Building on our previous study, we now explore the specificity and functional consequences of this interaction. We show that a four lysine module located within the B insert of Drp1 interacts preferentially with CL over other anionic lipids. This interaction dramatically enhances Drp1 oligomerization and assembly-stimulated GTP hydrolysis. Our results add significantly to a growing body of evidence indicating that CL is an important regulator of many essential mitochondrial functions.

Differential activity of GSK-3 isoforms regulates NF-kappa B and TRAIL- or TNF alpha induced apoptosis in pancreatic cancer cells

While TRAIL is a promising anticancer agent due to its ability to selectively induce apoptosis in neoplastic cells, many tumors, including pancreatic ductal adenocarcinoma (PDA), display intrinsic resistance, highlighting the need for TRAIL-sensitizing agents. Here we report that TRAIL-induced apoptosis in PDA cell lines is enhanced by pharmacological inhibition of glycogen synthase kinase-3 (GSK-3) or by shRNA-mediated depletion of either GSK-3 alpha or GSK-3 beta. In contrast, depletion of GSK-3 beta, but not GSK-3 alpha, sensitized PDA cell lines to TNF alpha-induced cell death. Further experiments demonstrated that TNF alpha-stimulated I kappa B alpha phosphorylation and degradation as well as p65 nuclear translocation were normal in GSK-3 beta-deficient MEFs. Nonetheless, inhibition of GSK-3 beta function in MEFs or PDA cell lines impaired the expression of the NF-kappa B target genes Bcl-xL and cIAP2, but not I kappa B alpha. Significantly, the expression of Bcl-xL and cIAP2 could be reestablished by expression of GSK-3 beta targeted to the nucleus but not GSK-3 beta targeted to the cytoplasm, suggesting that GSK-3 beta regulates NF-kappa B function within the nucleus. Consistent with this notion, chromatin immunoprecipitation demonstrated that GSK-3 inhibition resulted in either decreased p65 binding to the promoter of BIR3, which encodes cIAP2, or increased p50 binding as well as recruitment of SIRT1 and HDAC3 to the promoter of BCL2L1, which encodes Bcl-xL. Importantly, depletion of Bcl-xL but not cIAP2, mimicked the sensitizing effect of GSK-3 inhibition on TRAIL-induced apoptosis, whereas Bcl-xL overexpression ameliorated the sensitization by GSK-3 inhibition. These results not only suggest that GSK-3 beta overexpression and nuclear localization contribute to TNF alpha and TRAIL resistance via anti-apoptotic NF-kappa B genes such as Bcl-xL, but also provide a rationale for further exploration of GSK-3 inhibitors combined with TRAIL for the treatment of PDA.

Analytical method development for the uptake study of different organic pollutants by crops cultivated in compost-amended soils

256 p.

Os efeitos das drogas vasoativas na densidade capilar funcional intestinal de ratos endotoxêmicos: uma análise com videomicroscopia intravital

Introdução: o uso de drogas vasoativas para restaurar a pressão arterial em pacientes com choque séptico é frequentemente utilizada em medicina intensiva. No entanto, os agentes vasopressores podem acentuar a hipoperfusão esplâncnica durante o choque séptico facilitando a translocação bacteriana e endotoxemia. Neste estudo foram comparados os efeitos de diferentes drogas vasoativas na microcirculação intestinal e nos parâmetros de oxigenação tecidual independentemente de reposição volêmica, num modelo experimental de choque séptico. Métodos: Ratos Wistar Kyoto anestesiados com pentobarbital foram submetidos a choque endotoxêmico através da administração de 2mg/Kg IV de lipopolissacarídeo da Escherichia Coli. A pressão arterial média foi restaurada através da administração de diversas drogas vasoativa, incluindo adrenalina, noradrenalina, fenilefrina, dopamina, dobutamina e uma combinação de noradrenalina com dobutamina. A densidade capilar funcional (DCF) da camada muscular do intestino delgado foi avaliada através de microscopia intravital. Gasometria e concentração de lactato da veia mesentérica superior também foram analisadas. Resultados: A DCF diminui aproximadamente 25% a 60% após a administração intravenosa de adrenalina, noradrenalina e fenilefrina. A administração de dopamina, dobutamina e da associação de noradrenalina com dobutamina não reduziu significativamente a DCF intestinal. A concentração de lactato da veia mesentérica aumentou após a administração de fenilefrina e mostrou uma tendência de aumentar após o uso de adrenalina e noradrenalina enquanto não se observou aumento de lactato após o uso de dopamina, dobutamina e da associação entre noradrenalina e dobutamina. Conclusões: O estudo confirma a presença de uma dissociação entre alterações hemodinâmicas sistêmicas e alterações microcirculatórias num modelo experimental de choque séptico. Os resultados indicam que o uso de dopamina, dobutamina e da associação entre noradrenalina e dobutamina apresentam um efeito de proteção na microcirculação da camada muscular intestinal de ratos submetidos a choque endotoxêmico.

Ação molecular da 1,25(OH)2D3 em células endoteliais humanas submetidas a diferentes concentrações de leptina

Altas concentrações plasmáticas de leptina têm sido relacionadas ao aumento da formação de espécies reativas de oxigênio (ROS) que podem desempenhar um papel regulador central em eventos inflamatórios e cardiovasculares. Estudos recentes têm demonstrado que a vitamina D é capaz de reduzir marcadores do estresse oxidativo, bem como modular a produção de citocinas inflamatórias. O objetivo do presente estudo foi avaliar o efeito do pré-tratamento com concentração fisiológica (10-10 M) e suprafisiológica(10-7 M) de 1,25(OH)2D3 na produção do ânion superóxido (O2) e nos fatores de transcrição NF-κB e Nrf2,em células endoteliais humanas estimuladas com diferentes concentrações de leptina (1 e 10 ng/mL). Quando as células foram pré-tratadas com 1,25(OH)2D3, e estimuladas com leptina (1 e 10 ng/mL), a 1,25(OH)2D3 reduziu (p<0,05) a produção de ânion superóxido (O ), principalmente na concentração de 10-7 M. O fator de transcrição NF-κB foi positivamente ativado em células incubadas com 10 ng/mL de leptina, entretanto, quando se realizou o pré-tratamento com 1,25(OH)2D3 houve redução da translocação do NF-κB, assim como a produção de citocinas reguladas por este fator de transcrição. Também foi observado que o pré-tratamento com 10-7 M de 1,25(OH)2D3 aumentou de forma significativa (p<0,05) a expressão do fator de transcrição Nrf2 na fração nuclear em comparação ao controle, principalmente quando associada à 10 ng/mL de leptina (p<0,05). Tomados em conjunto, nossos resultados indicam que o tratamento com ambas as concentrações, 10-10 e 10-7 M de 1,25(OH)2D3 em células endoteliais humanas, foram eficazes em inibir a produção do ânion superóxido (O2), citocinas pró-inflamatórias, bem como inibir a translocação nuclear do fator de transcrição NF-κB, e ativar a via antioxidante Nrf2. Estes achados sugerem que o pré-tratamento com ambas as concentrações (fisiológica e suprafisiológica) de 1,25(OH)2D3 na presença de alta concentração de leptina, pode ter um efeito positivo no endotélio através da regulação de marcadores de inflamação e atividade antioxidante

Estudo da sinalização da insulina nos tecidos muscular e adiposo de ratos submetidos à desnutrição materna no início da lactação

Vários estudos sugerem que a desnutrição materna no período pós-natal poderia causar alterações na homeostase glicêmica da prole na vida adulta. Neste trabalho objetivamos investigar a interferência da programação metabólica induzida pela desnutrição protéica materna durante o início da lactação sobre a homeostase glicêmica e a sinalização da insulina nos tecidos muscular e adiposo. Animais desnutridos (D-dieta da mãe contendo 0% de proteína nos primeiros 10 dias de lactação) ou controle (C-dieta da mãe contendo 22% de proteína) foram estudados do nascimento até a vida adulta. Em resumo, observamos uma diminuição na insulina plasmática acompanhada de normoglicemia nos animais adultos desnutridos. A ativação do receptor de insulina (IR), após a estimulação com o hormônio apresentou-se diminuída durante o período de restrição protéica em músculo isolado destes animais experimentais. Durante o período da lactação, observamos uma diminuição na captação de glicose, na fosforilação do substrato para o receptor de insulina (IRS 1) e na translocação do GLUT 4 no tecido muscular. Na idade adulta, entretanto, houve aumento significativo na captação de glicose e translocação do GLUT 4 no músculo, associado com o aumento na expressão da PI3 quinase associada ao IRS 1. No tecido adiposo de ratos desnutridos adultos observamos menor fosforilação em tirosina tanto do IR quanto do IRS 1, que foi compensada pela maior ativação do IRS 2 e da PI3 quinase. Os níveis basais de pAkt e de GLUT 4 na membrana estavam aumentados, culminando em um aumento na captação de glicose. Observamos também uma redistribuição do citoesqueleto de actina e maior resistência aos efeitos da Ltrunculina B nos adipócitos dos ratos desnutridos. Em conclusão, este estudo demonstrou que a desnutrição materna no início da lactação é capaz de causar alterações na prole na vida adulta, o que parece estar relacionado com a expressão e ativação de proteínas chave na cascata da sinalização da insulina nos tecidos periféricos, importantes na regulação do metabolismo da glicose.

PEFCSH 的建立及在基因组特异序列克隆上的应用

基因组特异序列是跟踪外源染色质、鉴定易位系的特异探针。本文介绍一种带反馈控制的PCR增效减法杂交（PEFCSH），证明可高效克隆基因组特异序列。 带PCR接头的黑麦DNA片段与固定化的小麦ssDNA杂交，同源的片段将被吸附。用PCR扩增吸附的DNA，可监测杂交液中与小麦同源的DNA，确定是否还要再杂交。5轮连续杂交后，杂交液中的DNA几乎全为黑麦特异DNA，纯化后，用PCR扩增到方便操作的数量。经检测，PEFCSH片段99%为黑麦基因组特异性序列，富集度超过230倍。 PEFCSH片段克隆后检测：插入片段在120bp～2000bp，峰值250bp左右;306个克隆中301个显黑麦特异性，表明了PEFCSH的高效性。Tomita等曾用普通减法杂交富集黑麦特异序列，所得克隆只有6.3%为黑麦特异。 与数据库对比，分离片段有的为新序列，更多的与已知的黑麦特异重复序列同源。用其中一条作探针进行Southern杂交，小麦不显带，黑麦显阶梯型带，说明它是特异性串联重复序列。 PEFCSH有如下特点：1. 实时监测杂交液中非特异DNA，首次引入反馈控制，确保杂交达到预期效果。2. 用PCR制备Tester只需少量样品就可以分离特异序列。3. 采用固相减法杂交，大大简化Test与Driver的分离。4. 用PCR克服常规减法杂交操作性差的弱点。5. 富集特异单链和双链DNA，减少特异序列丢失。6. 适用于大多数分离两组相关核酸中的差异成分。

克隆整合与植物对沙地生境的适应－毛乌素沙地的案例

我国是受荒漠化影响最为严重的国家之一。半干旱区和干燥的亚湿润区分布着大面积沙地，这些沙地是我国荒漠化土地的集中分布区和的主要的潜在发生区，也是重点治理区。在这些地区进行生态建设和生态恢复的首要任务是植被的恢复与重建。用于植被恢复和重建的植物种，必需能够适应沙地特殊的生态环境。 克隆植物是一个独特的植物类群，它广泛的分布于各种生态系统中。在长期的进化过程中，克隆植物形成了有效利用异质性资源以及克服（忍耐或逃避）局部不利环境条件的生态适应对策―克隆整合。位于鄂尔多斯高原的毛乌素沙地是我国的四大沙地之一，其生态环境的特点具备我国沙地生境的共性－干旱、土壤贫瘠、频繁的风沙活动以及异质性。在毛乌素沙地中，克隆植物广泛分布。本文以毛乌素沙地为案例研究的背景，以该区几种重要的克隆植物为研究对象，以该区主要的生态环境特点为处理因素，从不同层面来观察克隆整合对这些植物适应沙地环境的作用。 高度异质性的水分分布格局是该区的关键生态因子之一。水分传输可以帮助克隆植物利用不同斑块内的水分资源。在一个野外实验中，采用酸性品红染色喂饲的方法，研究了根茎型草本克隆植物沙鞭和根茎型克隆半灌木羊柴的克隆内水分传播格局。沙鞭克隆内的水分传输速度和强度都高于羊柴。这可能是沙鞭能够占据大面积生境的原因之一。此外，克隆植物分株间资源的传递是通过贯通的维管束进行的。水分可以在观察的沙鞭克隆片断内畅通无阻的传输，但在羊柴克隆内的传输受到限制。这可能与二者维管束结构的不同有关。 沙埋是该区植物经常遭遇的生态事件。本文研究了克隆整合在羊柴遭受空间异质性沙埋过程中的作用。结果表明，轻微程度的沙埋可以促进羊柴的生长和生物量积累;高强度的沙埋会削弱羊柴的生长和生物量积累，甚至会致死。克隆整合可以帮助羊柴抵抗空间异质性沙埋，尤其当沙埋的强度增加时，这种作用表现的更明显。实际上，沙埋的发生是逐渐进行的，即同时具有时间异质性。本文通过野外实验观察了沙鞭在时空异质性沙埋条件下的响应格局以及克隆整合的作用。研究表明，长时间间隔的沙埋促进沙鞭的生物量积累，克隆整合可以帮助沙鞭抵抗频繁发生的沙埋事件。此外，通过Meta-analysis方法综合了分布在沙地中的根茎型克隆植物对沙埋的响应格局的案例研究。结果表明，轻微的沙埋能够促进根茎型克隆植物的生物量积累，高强度的沙埋对这些植物是一种生态胁迫，克隆整合可以帮助这些植物抵抗这种生态胁迫。这强烈的支持了这样一种观点，即克隆整合是根茎型克隆植物在长期的适应进化过程中形成的抵抗高强度沙埋的生态策略。 该区也生长着很多密集型克隆植物。养分的空间异质性在各种尺度上存在，密集型克隆植物也可能经历小尺度的养分异质性。以糙隐子草为研究对象，观察其在同质和异质养分条件下的生物量、生物量配置格局以及有性繁殖和克隆生长的权衡。结果表明：在异质性的养分条件下，相连的克隆片断的总体生物量、地上无性结构生物量、根生物量以及分株大小都显著高于切断的克隆片断;同样，异质性斑块中的相连的克隆片断的表现高于同质性斑块。这暗示着克隆整合能够帮助密集型克隆植物糙隐子草更好的利用小尺度的养分异质性。 此外，通过野外调查的方式观察该区两种重要的克隆半灌木，游击型的羊柴和密集型的油蒿在小尺度不同植被盖度斑块下的生物量配置格局。结果表明：羊柴的地上各部分生物量对植被盖度变化的响应不如油蒿敏感。这可能是因为羊柴的游击型克隆构型决定其可以跨越小尺度斑块实现克隆生理整合，从而利用不同小生境斑块的资源所致。油蒿只能利用小生境斑块内的资源，当小生境斑块的条件改变，其生物量以及配置方式也随之发生相应的变化。在繁殖方式上，羊柴的有性繁殖结构以及有性繁殖投资显著小于油蒿。在资源有限的条件下，对一种繁殖方式的投资常常会削弱另一种繁殖方式。羊柴主要依靠克隆生长，这符合并支持配置理论的观点。植物的空间格局与植物自身的生活史性状密切相关。羊柴和油蒿不同的生活史特性必然会在各自的种群空间格局中体现出来。本文还采用地统计学的方法，观察二者的种群空间格局。种群水平上，小尺度的空间自相关控制着羊柴种群的空间格局;油蒿种群的空间格局受更大尺度的过程控制，并在自身为建群种的群落随机分布。对于油蒿种群而言，发生在小于抽样尺度（<1m）的随机变异高于相应的羊柴种群。这两种克隆半灌木的种群空间格局的差异可能与二者克隆构型和克隆性的不同有关。 本文的研究对象不仅涉及根茎型克隆草本植物，还包括了克隆半灌木，不仅涉及游击型克隆植物，而且涵盖了密集型克隆植物。因此，本文的研究不仅有助于在理论上理解克隆植物对异质性生境的适应策略，在实践上也能为该区的生态恢复提供一定的理论依据。

干旱胁迫下草莓水分调控及光合特性研究

以盆栽草莓(Fragaria×ananassa)为材料研究了水分胁迫下克隆植物草莓母株和子株间的水分调控机制及其与碳同化、光系统II激发能分配的关系。实验材料分为匍匐茎连接和剪断两个大组，进行两步实验。第一步实验，对连接组和剪断组的所有母株控水，子株充分供水；4天后进入第二步实验，把连接组分为两小组，对其中一组充分供水子株开始控水，另一组保持不变。结果表明，土壤干旱引起母株叶片失水，并使其净光合速率和气孔导度显著降低。但是连接组中供水良好的子株能有效缓解缺水母株的水分胁迫。当供水良好的子株也开始受到干旱处理的时候，则会加剧与之相连母株的水分胁迫。受胁迫母株可以通过加强渗透调节能力和降低水势从相连子株获取水分。虽然土壤干旱会造成受胁迫母株叶片脱落酸（abscisic acid, ABA）含量的大幅度增加，但是与之相连子株的叶片ABA含量并没有增加；并且气孔导度与ABA变化趋势一致。因此，我们认为：(1)草莓母株和子株间的水分运输是由二者的水势差驱动的；（2）ABA不会通过匍匐茎在母株和子株间传递并影响相邻子株气孔导度；（3）在水分异质性较大情况下，生理整合可明显提高克隆系统的碳同化能力和光系统II激发能利用效率。 同时研究了水分胁迫对草莓叶片叶绿素荧光诱导动力学参数Fm的影响。结果表明，在水分胁迫初期, 活体草莓叶片失水萎缩、叶面积和叶片厚度减小，单位叶面积的叶绿素含量升高，此时叶绿素荧光动力学参数Fm上升；当水分胁迫进一步加剧，单位叶面积的叶绿素含量开始下降，但Fm没有随之下降。离体叶片测定则没有出现Fm上升这一过程，Fm随着单位叶面积叶绿素含量的下降而下降。叶片叠加实验证明，增加叶片厚度也可以使Fm上升。综上我们认为在干旱胁迫进程中，活体草莓叶片的荧光动力学参数Fm出现上升是由单位面积叶绿素含量和叶片结构的变化共同决定的。

THE CHROMOSOMES OF TUFTED DEER (ELAPHODUS-CEPHALOPHUS)

Mitotic and meiotic chromosome preparations of the tufted deer (Elaphodus cephalophus) were studied to elucidate the sex-chromosomal polymorphism evidenced by this species. Females had 2n = 46 or 47 chromosomes, whereas males had 2n = 47 or 48 chromosomes. An X;autosome translocation was identified by synaptonemal complex analysis of spermatocytes at pachytene and confirmed by the presence of a trivalent at diakinesis/metaphase I. The present work, in combination with earlier observations by others, indicates that E. cephalophus possesses a varied X-chromosome morphology involving an X;autosome translocation and addition of varying amounts of heterochromatin. It is speculated that sex-chromosome polymorphism may be responsible for the observed differences in diploid chromosome number of tufted deer.

Conserved chromosome segments in Hylobates hoolock revealed by human and H-leucogenys paint probes

A complete comparative chromosome map of the white-browed gibbon (Hylobates hoolock, 2n = 38), white-cheeked gibbon (Hylobates leucogenys, 2n = 52), and human has been established by hybridising H. leucogenys chromosome-specific paints and human 24-colour paints onto H. hoolock metaphase chromosomes. In the 18 H. hoolock autosomes, we identified 62 conserved segments that showed DNA homology to regions of the 25 H. leucogenys autosomes, Numerous interchromosomal rearrangements differentiate the karyotypes of H. leucogenys and H. hoolock. Only H. hoolock chromosome 10 showed homology to one entire autosome of H. leucogenys. The hybridisation of human 24-colour paints not only confirmed most of the chromosome correspondences between human and H. hoolock established previously but also helped to correct five erroneous assignments and revealed three new segments. Our results demonstrate that the karyotypes of the extant gibbons have arisen mainly through extensive translocation events and that the karyotype of H. hoolock more closely resembles the ancestral karyotype of Hylobates, rather than the karyotype of H. leucogenys. Copyright (C) 2001 S. Karger AG, Basel.

Karyotypic relationships of horses and zebras: results of cross-species chromosome painting

Complete sets of chromosome-specific painting probes, derived from flow-sorted chromosomes of human (HSA), Equus caballus (ECA) and Equus burchelli (EBU) were used to delineate conserved chromosomal segments between human and Equits burchelli, and among four equid species, E. przewalskii (EPR), E. caballus, E. burchelli and E. zebra hartmannae (EZH) by cross-species chromosome painting. Genome-wide comparative maps between these species have been established. Twenty-two human autosomal probes revealed 48 conserved segments in E. burchelli. The adjacent segment combinations HSA3/21, 7/16p, 16q/19q, 14/15, 12/22 and 4/8, presumed ancestral syntenies for all eutherian mammals, were also found conserved in E. burchelli. The comparative maps of equids allow for the unequivocal characterization of chromosomal rearrangements that differentiate the karyotypes of these equid species. The karyotypes of E. przewalskii and E. caballus differ by one Robertsonian translocation (ECA5 = EPR23 + EPR24); numerous Robertsonian translocations and tandem fusions and several inversions account for the karyotypic differences between the horses and zebras. Our results shed new light on the karyotypic evolution of Equidae. Copyright (C) 2003 S. Karger AG, Basel.

The mitochondrial genome organization of the rice frog, Fejervarya limnocharis (Amphibia : Anura): a new gene order in the vertebrate mtDNA

The mitochondrial DNA of the rice frog, Fejervarya limnocharis (Amphibia, Anura), was obtained using long-and-accurate polymerase chain reaction (LA-PCR) combining with subcloning method. The complete nucleotide sequence (17,717 bp) of mitochondrial genome was determined subsequently. This mitochondrial genome is characterized by four distinctive features: the translocation of ND5 gene, a cluster of rearranged tRNA genes (tRNA(Thr), tRNA(Pro), tRNA(Leu) ((CUN))) a tandem duplication of tRNA(Mer) gene, and eight large 89-bp tandem repeats in the control region, as well as three short noncoding regions containing two repeated motifs existing in the gene cluster of ND5/tRNA(Thr)/tRNA(Pro)/tRNA(Leu)/tRNA(Phe). The tandem duplication of gene regions followed by deletions of supernumerary genes can be invoked to explain the shuffling of tRNAM(Met) and a cluster of tRNA and ND5 genes, as observed in this study. Both ND5 gene translocation and tandem duplication of tRNA(Met) were first observed in the vertebrate mitochondrial genomes. (c) 2004 Elsevier B.V. All rights reserved.

Nanotubes complexed with DNA and proteins for resistive-pulse sensing

We use a resistive-pulse technique to analyze molecular hybrids of single-wall carbon nanotubes (SWNTs) wrapped in either single-stranded DNA or protein. Electric fields confined in a glass capillary nanopore allow us to probe the physical size and surface properties of molecular hybrids at the single-molecule level. We find that the translocation duration of a macromolecular hybrid is determined by its hydrodynamic size and solution mobility. The event current reveals the effects of ion exclusion by the rod-shaped hybrids and possible effects due to temporary polarization of the SWNT core. Our results pave the way to direct sensing of small DNA or protein molecules in a large unmodified solid-state nanopore by using nanofilaments as carriers. © 2013 American Chemical Society.

Elongation Factor ELL (Eleven-Nineteen Lysine-rich Leukemia) Acts as a Transcription Factor for Direct Thrombospondin-1 Regulation

The eleven-nineteen lysine-rich leukemia (ELL) gene undergoes translocation and fuses in-frame to the multiple lineage leukemia gene in a substantial proportion of patients suffering from acute forms of leukemia. Studies show that ELL indirectly modulates transcription by serving as a regulator for transcriptional elongation as well as for p53, U19/Eaf2, and steroid receptor activities. Our in vitro and in vivo data demonstrate that ELL could also serve as a transcriptional factor to directly induce transcription of the thrombospondin-1 (TSP-1) gene. Experiments using ELL deletion mutants established that full-length ELL is required for the TSP-1 up-regulation and that the trans-activation domain likely resides in the carboxyl terminus. Moreover, the DNA binding domain may localize to the first 45 amino acids of ELL. Not surprisingly, multiple lineage leukemia-ELL, which lacks these amino acids, did not induce expression from the TSP-1 promoter. In addition, the ELL core-response element appears to localize in the -1426 to -1418 region of the TSP-1 promoter. Finally, studies using zebrafish confirmed that ELL regulates TSP-1 mRNA expression in vivo, and ELL could inhibit zebrafish vasculogenesis, at least in part, through up-regulating TSP-1. Given the importance of TSP-1 as an anti-angiogenic protein, our findings may have important ramifications for better understanding cancer.