scholarly journals Helix-loop-helix proteins LYL1 and E2a form heterodimeric complexes with distinctive DNA-binding properties in hematolymphoid cells.

1996 ◽  
Vol 16 (5) ◽  
pp. 2394-2401 ◽  
Author(s):  
A Miyamoto ◽  
X Cui ◽  
L Naumovski ◽  
M L Cleary
Keyword(s):  
Dna Binding ◽  
Cell Lines ◽  
Target Genes ◽  
Protein Complexes ◽  
Lymphoblastic Leukemia ◽  
Cell Receptor ◽  
Binding Properties ◽  
Helix Loop Helix ◽  
Dna Binding Properties

LYL1 is a basic helix-loop-helix (HLH) protein that was originally discovered because of its translocation into the beta T-cell receptor locus in an acute lymphoblastic leukemia. LYL1 is expressed in many hematolymphoid cells, with the notable exceptions of thymocytes and T cells. Using the yeast two-hybrid system to screen a cDNA library constructed from B cells, we identified the E-box-binding proteins E12 and E47 as potential lymphoid dimerization partners for LYL1. The interaction of LYL1 with E2a proteins was further characterized in vitro and shown to require the HLH motifs of both proteins. Immunoprecipitation analyses showed that in T-ALL and other cell lines, endogenous LYL1 exists in a complex with E2a proteins. A preferred DNA-binding sequence, 5'-AACAGATG(T/g)T-3', for the LYL1-E2a heterodimer was determined by PCR-assisted site selection. Endogenous protein complexes containing both LYL1 and E2a bound this sequence in various LYL1-expressing cell lines and could distinguish between the LYL1 consensus and muE2 sites. These data demonstrate that E2a proteins serve as dimerization partners for the basic HLH protein LYL1 to form complexes with distinctive DNA-binding properties and support the hypothesis that the leukemic properties of the LYL1 and TAL subfamily of HLH proteins could be mediated by recognition of a common set of target genes as heterodimeric complexes with class I HLH proteins.

Tal1 and a DNA Binding Mutant (Tal1R188G;R189G) Cooperate with LMO2 To Induce Leukemia in Mice.

Blood ◽  
2006 ◽  
Vol 108 (11) ◽  
pp. 1414-1414
Author(s):  
Kyle M. Draheim ◽  
Kimberly Erdkamp ◽  
Eward Arous ◽  
Jennifer A. Calvo ◽  
Michelle A. Kelliher
Keyword(s):  
T Cell ◽  
Dna Binding ◽  
Transgenic Mice ◽  
Target Genes ◽  
Lymphoblastic Leukemia ◽  
Ectopic Expression ◽  
Thymocyte Development ◽  
Binding Properties ◽  
Transcriptional Complex ◽  
Dna Binding Properties

Abstract LMO2 is a member of the “LIM only” protein family and required for primitive erythropoiesis and adult vasculogenesis and angiogenesis. In erythroid cells, LMO2 interacts with TAL1 and E47 and LDB1 and GATA-1, thereby forming a transcriptional complex whose target genes include EKLF, CKIT, and p4.2 (protein 4.2). LMO2 was first implicated in leukemogenesis when it was identified in chromosomal translocations t(11;14)(p13;q11) and t(7;11)(q35;p13) found in T cell acute lymphoblastic leukemia (T-ALL) patients. Ectopic expression of LMO2 in mice recapitulates the human disease, albeit at low penetrance and following a long latency. LMO2 has been shown to synergize with TAL1, yet the mechanism of oncogene cooperativity is unknown. Two models have been proposed: the first suggests that LMO2 and TAL1 synergize by forming an active transcriptional complex that induces expression of target genes such as retinaldehyde dehydrogenase 2 (RALDH2) and TALLA1 (a surface marker of T-ALL). The second model proposes that LMO2 and TAL1 sequester the E47/HEB heterodimer, resulting in inhibition of E47/HEB-mediated transcription. To distinguish between these models, we mated our Tal1 transgenic mice and our DNA binding mutant of Tal1(R188G:R189G) with Lmo2 transgenic mice. As expected, transgenic expression of Lmo2 induced disease in 23% of mice after 302 days. Similar to published studies, Tal1 and Lmo2 expression dramatically inhibited thymocyte development and induced T cell leukemia in 100% of the mice with a mean latency of 108 days. To test whether the DNA binding properties of tal1 were required to cooperate with LMO2, we mated mice expressing a DNA binding mutant of Tal1(R188G;R189G) with Lmo2 transgenic mice and found that tumors were induced with similar kinetics; 100% of mice developed disease with an average latency of 107 days. These data suggest LMO2 does not require the DNA-binding properties of Tal1 to induce leukemia in mice and support the model that LMO2 contributes to leukemia through E47/HEB sequestration and inhibition.

Hox proteins have different affinities for a consensus DNA site that correlate with the positions of their genes on the hox cluster

1994 ◽  
Vol 14 (7) ◽  
pp. 4532-4545
Author(s):  
I Pellerin ◽  
C Schnabel ◽  
K M Catron ◽  
C Abate
Keyword(s):  
Dna Binding ◽  
Target Genes ◽  
Hox Genes ◽  
Regulatory Elements ◽  
Binding Properties ◽  
Hox Proteins ◽  
Hox Cluster ◽  
Dna Binding Properties

The hox genes, members of a family of essential developmental regulators, have the intriguing property that their expression in the developing murine embryo is colinear with their chromosomal organization. Members of the hox gene family share a conserved DNA binding domain, termed the homeodomain, which mediates interactions of Hox proteins with DNA regulatory elements in the transcriptional control regions of target genes. In this study, we characterized the DNA binding properties of five representative members of the Hox family: HoxA5, HoxB4, HoxA7, HoxC8, and HoxB1. To facilitate a comparative analysis of their DNA binding properties, we produced the homeodomain regions of these Hox proteins in Escherichia coli and obtained highly purified polypeptides. We showed that these Hox proteins interact in vitro with a common consensus DNA site that contains the motif (C/G)TAATTG. We further showed that the Hox proteins recognize the consensus DNA site in vivo, as determined by their ability to activate transcription through this site in transient transfection assays. Although they interact optimally with the consensus DNA site, the Hox proteins exhibit subtle, but distinct, preferences for DNA sites that contain variations of the nucleotides within the consensus motif. In addition to their modest differences in DNA binding specificities, the Hox proteins also vary in their relative affinities for DNA. Intriguingly, their relative affinities correlate with the positions of their respective genes on the hox cluster. These findings suggest that subtle differences in DNA binding specificity combined with differences in DNA binding affinity constitute features of the "Hox code" that contribute to the selective functions of Hox proteins during murine embryogenesis.

scholarly journals Hox proteins have different affinities for a consensus DNA site that correlate with the positions of their genes on the hox cluster.

1994 ◽  
Vol 14 (7) ◽  
pp. 4532-4545 ◽  
Author(s):  
I Pellerin ◽  
C Schnabel ◽  
K M Catron ◽  
C Abate
Keyword(s):  
Dna Binding ◽  
Target Genes ◽  
Hox Genes ◽  
Regulatory Elements ◽  
Binding Properties ◽  
Hox Proteins ◽  
Hox Cluster ◽  
Dna Binding Properties

The hox genes, members of a family of essential developmental regulators, have the intriguing property that their expression in the developing murine embryo is colinear with their chromosomal organization. Members of the hox gene family share a conserved DNA binding domain, termed the homeodomain, which mediates interactions of Hox proteins with DNA regulatory elements in the transcriptional control regions of target genes. In this study, we characterized the DNA binding properties of five representative members of the Hox family: HoxA5, HoxB4, HoxA7, HoxC8, and HoxB1. To facilitate a comparative analysis of their DNA binding properties, we produced the homeodomain regions of these Hox proteins in Escherichia coli and obtained highly purified polypeptides. We showed that these Hox proteins interact in vitro with a common consensus DNA site that contains the motif (C/G)TAATTG. We further showed that the Hox proteins recognize the consensus DNA site in vivo, as determined by their ability to activate transcription through this site in transient transfection assays. Although they interact optimally with the consensus DNA site, the Hox proteins exhibit subtle, but distinct, preferences for DNA sites that contain variations of the nucleotides within the consensus motif. In addition to their modest differences in DNA binding specificities, the Hox proteins also vary in their relative affinities for DNA. Intriguingly, their relative affinities correlate with the positions of their respective genes on the hox cluster. These findings suggest that subtle differences in DNA binding specificity combined with differences in DNA binding affinity constitute features of the "Hox code" that contribute to the selective functions of Hox proteins during murine embryogenesis.

Synthesis of hybrids thiazole-quinoline, thiazole-indole and analogs: in vitro anti-proliferative effects on cancer cell lines, DNA binding properties and molecular modeling

2021 ◽  
Author(s):  
Paulo Santos-Júnior ◽  
Igor José dos Santos Nascimento ◽  
Edjan Carlos Dantas da Silva ◽  
Kadja Monteiro ◽  
Johnnatan Freitas ◽  
...  
Keyword(s):  
Molecular Modeling ◽  
Dna Binding ◽  
Cell Lines ◽  
Cancer Cell ◽  
Cancer Cell Lines ◽  
Binding Properties ◽  
Hybrid Compounds ◽  
Convenient Synthesis ◽  
Dna Binding Properties

A convenient synthesis under ultrasound (US) irradiation of 4-thiazolidinone, thiazole, dihydrothiazole, and thiazine hybrid compounds containing quinoline and indole nucleus is described. All the title compounds were characterized by NMR...

Synthesis and DNA-binding Properties of a Cationic Seven-coordinate Manganese(II) Complex Formed with the Tripodal Ligand Tris(Nmethylbenzimidazol- 2-ylmethyl)amine and Salicylate

2012 ◽  
Vol 67 (8) ◽  
pp. 819-826 ◽  
Author(s):  
Huilu Wu ◽  
Ying Bai ◽  
Jingkun Yuan ◽  
Hua Wang ◽  
Guolong Pan ◽  
...  
Keyword(s):  
Dna Binding ◽  
Binding Mode ◽  
X Ray Diffraction ◽  
Binding Properties ◽  
Tripodal Ligand ◽  
Spectrophotometric Methods ◽  
Physico Chemical ◽  
Dna Binding Properties ◽  
Hydroxyl Radical Scavenge

A ternary cationic Mn(II) complex with the tripodal ligand tris(2-(N-methyl) benzimidazylmethyl)amine (Mentb), salicylate and DMF as ligands and nitrate as counterion, [Mn(Mentb)(salicylate)DMF](NO3), was synthesized and characterized by physico-chemical and spectroscopic methods. The crystal structure of the Mn(II) complex has been determined by single-crystal X-ray diffraction and revealed that the central Mn(II) atom is seven-coordinated. The DNA-binding properties of the Mn(II) complex were investigated by spectrophotometric methods and viscosity measurements, and the results suggest that the Mn(II) complex binds to DNA via an intercalation binding mode. Additionally, the complex exhibited potential hydroxyl radical scavenge properties in in vitro studies

Synthesis, Crystal Structure, DNA-binding Properties and Antioxidant Activities of a Lutetium(III) Complex with the Bis(N-salicylidene)-3- oxapentane-1,5-diamine Ligand

2013 ◽  
Vol 68 (3) ◽  
pp. 257-266 ◽  
Author(s):  
Guolong Pan ◽  
Yuchen Bai ◽  
Hua Wang ◽  
Jin Kong ◽  
Furong Shi ◽  
...  
Keyword(s):  
Crystal Structure ◽  
Dna Binding ◽  
Antioxidant Activities ◽  
Radical Scavenging ◽  
Binding Mode ◽  
Binding Properties ◽  
Metal Centers ◽  
Spectrophotometric Methods ◽  
Dna Binding Properties

A Schiff base ligand bis(N-salicylidene)-3-oxapentane-1,5-diamine (H2L) and its lutetium(III) complex, with composition Lu2(L)2(NO3)2, were synthesized and characterized by physico-chemical and spectroscopic methods. The crystal structure of the Lu(III) complex has been determined by single-crystal X-ray diffraction. It reveals a centrosymmetric binuclear neutral entity where Lu(III) metal centers are bridged by two phenoxo oxygen atoms. The DNA-binding properties of the Lu(III) complex were investigated by spectrophotometric methods and viscosity measurements, and the results suggest that the Lu(III) complex binds to DNA via a groove binding mode. Additionally, the antioxidant activity of the Lu(III) complex was determined by the superoxide and hydroxyl radical scavenging methods in vitro, which indicate that it is a scavenger for OH· and O-· 2 radicals.

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