Evaluation of cobalt complexes with tripod ligands for zinc finger targeting

2020 ◽  
Vol 49 (45) ◽  
pp. 16143-16153 ◽  
Author(s):  
Heiðar Mar Aðalsteinsson ◽  
Frederico A. Lima ◽  
Carolina Galuppo ◽  
Camilla Abbehausen

We report the ability of CoII and CoIII complexes of tri(2-pyridylmethyl)amine and N,N-di(2-pyridylmethyl)glycinate to disrupt zinc fingers.

1992 ◽  
Vol 12 (5) ◽  
pp. 1940-1949
Author(s):  
A D Keller ◽  
T Maniatis

The eukaryotic transcriptional repressor PRDI-BF1 contains five zinc fingers of the C2H2 type, and the protein binds specifically to PRDI, a 14-bp regulatory element of the beta interferon gene promoter. We have investigated the amino acid sequence requirements for specific binding to PRDI and found that the five zinc fingers and a short stretch of amino acids N terminal to the first finger are necessary and sufficient for PRDI-specific binding. The contribution of individual zinc fingers to DNA binding was investigated by inserting them in various combinations into another zinc finger-containing DNA-binding protein whose own fingers had been removed. We found that insertion of PRDI-BF1 zinc fingers 1 and 2 confer PRDI-binding activity on the recipient protein. In contrast, the insertion of PRDI-BF1 zinc fingers 2 through 5, the insertion of zinc finger 1 or 2 alone, and the insertion of zinc fingers 1 and 2 in reverse order did not confer PRDI-binding activity. We conclude that the first two PRDI-BF1 zinc fingers together are sufficient for the sequence-specific recognition of PRDI.


2020 ◽  
Vol 12 (3) ◽  
pp. 174-184
Author(s):  
Alexandra N Nail ◽  
Jeramiah J Smith ◽  
Martha L Peterson ◽  
Brett T Spear

Abstract The Zinc Fingers and Homeoboxes (Zhx) proteins, Zhx1, Zhx2, and Zhx3, comprise a small family of proteins containing two amino-terminal C2–H2 zinc fingers and four or five carboxy-terminal homeodomains. These multiple homeodomains make Zhx proteins unusual because the majority of homeodomain-containing proteins contain a single homeodomain. Studies in cultured cells and mice suggest that Zhx proteins can function as positive or negative transcriptional regulators. Zhx2 regulates numerous hepatic genes, and all three Zhx proteins have been implicated in different cancers. Because Zhx proteins contain multiple predicted homeodomains, are associated with interesting physiological traits, and seem to be only present in the vertebrate lineage, we investigated the evolutionary history of this small family by comparing Zhx homologs from a wide range of chordates. This analysis indicates that the zinc finger motifs and homeodomains are highly similar among all Zhx proteins and also identifies additional Zhx-specific conserved regions, including a 13 amino acid amino-terminal motif that is nearly identical among all gnathostome Zhx proteins. We found single Zhx proteins in the sea lamprey (Petromyzon marinus) and in the nonvertebrate chordates sea squirt (Ciona intestinalis) and lancelet (Branchiostoma floridae); these Zhx proteins are most similar to gnathostome Zhx3. Based on our analyses, we propose that a duplication of the primordial Zhx gene gave rise to Zhx3 and the precursor to Zhx1 and Zhx2. A subsequent tandem duplication of this precursor generated Zhx1 and Zhx2 found in gnathostomes.


1993 ◽  
Vol 48 (12) ◽  
pp. 1707-1714 ◽  
Author(s):  
A. Asam ◽  
B. Janssen ◽  
G. Huttner ◽  
L. Zsolnai ◽  
O. Walter

The tripod ligands RCH2C(CH2PPh2)3 react with (CH3CN)6Fe(BF4)2 to yield the tripod-Fe(II) complexes RCH2C(CH2PPh2)3Fe(CH3CN)3(BF4)2 (R = H, la; R = Ph, lb). The octahedral low spin Fe(II) compounds are shown by cyclic voltammetry to undergo reversible one electron oxidation at +1.47 V (vs. SCE) to give the corresponding Fe(III) derivatives.In a similar way (CH3CN)6Co(BF4)2 reacts with the same tripod ligands to produce the tripod-Co(II) complexes RCH2C(CH2PPh2)3Co(CH3CN)2(BF4)2 (R = H, 2a; R = Ph, 2b). The compounds are paramagnetic (2a, g = 2.123; 2b, g = 2.129). The structure of complex 2b shows that the tripod ligand is facially coordinated with one longer (233.1 pm) and two shorter (about 222 pm) Co—P bonds. Reversible reduction is found for 2a at —0.30 V by cyclic voltammetry. The compounds have been characterized by spectroscopic and analytical techniques including X-ray analyses.


Molecules ◽  
2020 ◽  
Vol 25 (18) ◽  
pp. 4177 ◽  
Author(s):  
Aleksandra Witkiewicz-Kucharczyk ◽  
Wojciech Goch ◽  
Jacek Olędzki ◽  
Andrea Hartwig ◽  
Wojciech Bal

Tetrathiolate zinc fingers are potential targets of oxidative assault under cellular stress conditions. We used the synthetic 37-residue peptide representing the tetrathiolate zinc finger domain of the DNA repair protein XPA, acetyl-DYVICEECGKEFMSYLMNHFDLPTCDNCRDADDKHK-amide (XPAzf) as a working model to study the reaction of its Zn(II) complex (ZnXPAzf) with hydrogen peroxide and S-nitrosoglutathione (GSNO), as oxidative and nitrosative stress agents, respectively. We also used the Cd(II) substituted XPAzf (CdXPAzf) to assess the situation of cadmium assault, which is accompanied by oxidative stress. Using electrospray mass spectrometry (ESI-MS), HPLC, and UV-vis and circular dichroism spectroscopies we demonstrated that even very low levels of H2O2 and GSNO invariably cause irreversible thiol oxidation and concomitant Zn(II) release from ZnXPAzf. In contrast, CdXPAzf was more resistant to oxidation, demonstrating the absence of synergy between cadmium and oxidative stresses. Our results indicate that GSNO cannot act as a reversible modifier of XPA, and rather has a deleterious effect on DNA repair.


1995 ◽  
Vol 311 (1) ◽  
pp. 219-224 ◽  
Author(s):  
T C Schulz ◽  
B Hopwood ◽  
P D Rathjen ◽  
J R Wells

The zinc finger is a protein domain that imparts specific nucleic acid-binding activity on a wide range of functionally important proteins. In this paper we report the molecular cloning and characterization of a novel murine zinc-finger gene, mZ13. Analysis of mZ13 cDNAs revealed that the gene expresses a 794-amino-acid protein encoded by a 2.7 kb transcript. The protein has an unusual arrangement of 13 zinc fingers into a ‘hand’ of 12 tandem fingers and a single isolated finger near the C-terminus. This structural organization is conserved with the probable chicken homologue, cZ13. mZ13 also contained an additional domain at the N-terminus which has previously been implicated in the regulation of zinc-finger transcription factor DNA-binding, via protein-protein interactions. mZ13 expression was detected in a wide range of murine embryonic and adult tissues. The structural organization of mZ13 and its expression profile suggest that it may function as a housekeeping DNA-binding protein that regulates the expression of specific genes.


Blood ◽  
2012 ◽  
Vol 120 (21) ◽  
pp. 1448-1448
Author(s):  
Huiyu Li ◽  
Xiaomei Chen ◽  
Wei Xiong ◽  
Fang Liu ◽  
Shiang Huang

Abstract Abstract 1448 Microvesicles (MVs) are submicrometric membrane fragments and they can “hijack” membrane components and engulf cytoplasmic contents from their cellular origin. MVs are enriched in various bioactive molecules of their parental cells, such as proteins, DNA, mRNA and miRNAs. Microvesicles (MVs) released by leukemia cells constitute an important part of the leukemia microenvironment. As a cell-to-cell communication tool, MVs transfer microRNA (miRNA) between cells. MVs miRNAs may also provide an insight in the role of miRNAs playing in the underlying of pathophysiologic processes of various leukemia. We determined the miRNA expression profiles of ALL-derived MVs using Agilent miRNA microarray analysis. The five miRNAs obtained by microarray profiling were validated using real-time PCR. The putative target genes were predicted by bioformation software. We identified 182 and 166 dysregulated miRNAs in MVs derived from Nalm 6 cells and from Jurkat cells, respectively. Both up regulated (123/182 in Nalm 6-MVs and 114/166 in Jurkat- MVs) and down regulated (59/182 in Nalm 6-MVs and 52/166 in Jurkat- MVs) expressions were observed compared with MVs from normal peripheral blood the MVs normal control. When we analyzed those miRNA with bioinformatic tools (TargetScan), we found an interesting phenomenon that presence of 111 zinc fingers genes were regulated by 52 miRNAs, indicating that the ALL-microvesicles were enriched with miRNAs regulating zinc finger proteins. They encompassed zinc fingers and homeoboxes 2, zinc finger, ZZ-type containing 3, zinc finger, SWIM-type containing 1, zinc finger, RAN-binding domain containing 3, zinc finger, NFX1-type containing 1, zinc finger, MYM-type 4, zinc finger, FYVE domain containing 1 and their 5 subtypes; zinc finger, DHHC-type containing16, and other subtypes; zinc finger, CCHC domain containing 14 and 7A, zinc finger, BED-type containing 4; zinc finger protein, X-linked; zinc finger protein, multitype 2; zinc finger protein 81, and their 55 subtypes; zinc finger and SCAN domain containing 18, zinc finger and BTB domain containing 9. ALL-microvesicles were enriched with expression changes of distinct sets of miRNAs regulating zinc finger proteins. This provides clues that genes commonly function together. It is worth noting that 52 miRNA regulating above zinc finger protein genes were up-expressed, suggeting that miRNA regulating zinc fingers were active in ALL-MVs. Zinc finger proteins are important transcriptions in eukaryotes and play roles in regulating gene. Some members of the Zinc finger family have close relationaship with tumour. Zinc finger X-chromosomal protein (Zfx) is a protein that in humans is encoded by the ZFX gene. The level of Zfx expression correlates with aggressiveness and severity in many cancer types, including prostate cancer, breast cancer, gastric tumoural tissues, and leukemia. [1,2]. Zinc finger and homeoboxes 2 (ZHX2) was target gene of miRNA-1260. The role of miRNA are negatively regulated host gene expressions. ZHX2 inhibits HCC cell proliferation by preventing expression of Cyclins A and E, and reduces growth of xenograft tumors. Loss of nuclear ZHX2 might be an early step in the development of HCC[3]. In our study, the miRNA-1260 were 9 fold higher in ALL MVs. In leukeima microenvironment, ALL-MVs may transfer aberantly expressed miRNAs to their target cell lead to abnormally regulated the zinc finger proteins that may play roles in ALL. In this study, we demonstrated that ALL-microvesicles were enriched with expression changes of distinct sets of miRNAs regulating zinc finger proteins. Futhermore, Zinc fingers were active in ALL-MVs and commonly function together. Disclosures: No relevant conflicts of interest to declare.


2010 ◽  
Vol 43 (1) ◽  
pp. 1-21 ◽  
Author(s):  
Aaron Klug

AbstractA long-standing goal of molecular biologists has been to construct DNA-binding proteins for the control of gene expression. The classical Cys2His2 (C2H2) zinc finger design is ideally suited for such purposes. Discriminating between closely related DNA sequences both in vitro and in vivo, this naturally occurring design was adopted for engineering zinc finger proteins (ZFPs) to target genes specifically.Zinc fingers were discovered in 1985, arising from the interpretation of our biochemical studies on the interaction of the Xenopus protein transcription factor IIIA (TFIIIA) with 5S RNA. Subsequent structural studies revealed its three-dimensional structure and its interaction with DNA. Each finger constitutes a self-contained domain stabilized by a zinc (Zn) ion ligated to a pair of cysteines and a pair of histidines and also by an inner structural hydrophobic core. This discovery showed not only a new protein fold but also a novel principle of DNA recognition. Whereas other DNA-binding proteins generally make use of the 2-fold symmetry of the double helix, functioning as homo- or heterodimers, zinc fingers can be linked linearly in tandem to recognize nucleic acid sequences of varying lengths. This modular design offers a large number of combinatorial possibilities for the specific recognition of DNA (or RNA). It is therefore not surprising that the zinc finger is found widespread in nature, including 3% of the genes of the human genome.The zinc finger design can be used to construct DNA-binding proteins for specific intervention in gene expression. By fusing selected zinc finger peptides to repression or activation domains, genes can be selectively switched off or on by targeting the peptide to the desired gene target. It was also suggested that by combining an appropriate zinc finger peptide with other effector or functional domains, e.g. from nucleases or integrases to form chimaeric proteins, genomes could be modified or manipulated.The first example of the power of the method was published in 1994 when a three-finger protein was constructed to block the expression of a human oncogene transformed into a mouse cell line. The same paper also described how a reporter gene was activated by targeting an inserted 9-base pair (bp) sequence, which acts as the promoter. Thus, by fusing zinc finger peptides to repression or activation domains, genes can be selectively switched off or on. It was also suggested that, by combining zinc fingers with other effector or functional domains, e.g. from nucleases or integrases, to form chimaeric proteins, genomes could be manipulated or modified.Several applications of such engineered ZFPs are described here, including some of therapeutic importance, and also their adaptation for breeding improved crop plants.


Science ◽  
2018 ◽  
Vol 362 (6414) ◽  
pp. eaat0572 ◽  
Author(s):  
Quinlan L. Sievers ◽  
Georg Petzold ◽  
Richard D. Bunker ◽  
Aline Renneville ◽  
Mikołaj Słabicki ◽  
...  

The small molecules thalidomide, lenalidomide, and pomalidomide induce the ubiquitination and proteasomal degradation of the transcription factors Ikaros (IKZF1) and Aiolos (IKZF3) by recruiting a Cys2-His2 (C2H2) zinc finger domain to Cereblon (CRBN), the substrate receptor of the CRL4CRBN E3 ubiquitin ligase. We screened the human C2H2 zinc finger proteome for degradation in the presence of thalidomide analogs, identifying 11 zinc finger degrons. Structural and functional characterization of the C2H2 zinc finger degrons demonstrates how diverse zinc finger domains bind the permissive drug-CRBN interface. Computational zinc finger docking and biochemical analysis predict that more than 150 zinc fingers bind the drug-CRBN complex in vitro, and we show that selective zinc finger degradation can be achieved through compound modifications. Our results provide a rationale for therapeutically targeting transcription factors that were previously considered undruggable.


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