Cloning the cDNA for a new human zinc finger protein defines a group of closely related krüppel like transcription factors. (1998 Nov)
cloning the cDNA for a new human zinc finger protein defines a group of closely related krüppel like transcription factors . We have identified a novel zinc finger protein that has been named ubiquitous krüppel like factor ( UKLF ) based on structural considerations and the pattern of gene expression . UKLF was isolated by the polymerase chain reaction approach using degenerate oligonucleotides corresponding to the DNA binding domain of erythroid krüppel like factor ( EKLF ) and cDNA prepared from human vascular endothelial cells . The carboxyl terminal portion of UKLF contains three zinc fingers of the Cys2 His2 type and binds in vitro to the caccc motif of the beta globin promoter and to the Sp1 recognition sequence . The amino terminal portion of UKLF consists of a hydrophobic region rich in serines and a negatively charged segment with several glutamic acid residues . The first 47 amino acids of the acidic region are nearly identical to the amino terminal portion of another krüppel like factor , the so called core promoter binding protein ( CPBP ) or Zf9 . Like CPBP / Zf9 , UKLF can function as a transcription activator in co transfection assays . however , this activity is lost when the highly conserved amino terminal segment is deleted . these findings indicate that UKLF and CPBP / Zf9 represent a distinct subgroup of closely related krüppel like activators of transcription . mapping of the UKLF gene to chromosome 2 suggested that UKLF and CPBP …

Zinc finger transcription factors designed for bispecific coregulation of erbb2 and erbb3 receptors : insights into ErbB receptor biology. (2005 Oct)
Zinc finger transcription factors designed for bispecific coregulation of erbb2 and erbb3 receptors : insights into ErbB receptor biology . signaling through the ErbB family of tyrosine kinase receptors in normal and cancer derived cell lines contributes to cell growth and differentiation . In this work , we altered the levels of erbb2 and erbb3 receptors , individually and in combination , by using 6 finger and 12 finger synthetic zinc finger protein artificial transcription factors ( ATFs ) in an epidermoid squamous cell carcinoma line , A431 . We successfully designed 12 finger ATFs capable of coregulating erbb3 and ICAM 1 or erbb2 and erbb3 . With ATFs , the effects of changes in erbb2 and erbb3 receptor levels were evaluated by using cell proliferation , cell migration , and cell signaling assays . Cell proliferation was increased when erbb2 and erbb3 were both overexpressed . Cell migration on collagen was decreased when erbb2 was down regulated , yet migration on laminin was significantly increased with erbb3 overexpression . erbb2 and erbb3 overexpression also stimulated the phosphatidylinositol 3 kinase and mitogen activated protein kinase pathways . Our ATF approach has elucidated differences in ErbB receptor mediated proliferation , migration , and intracellular signaling that cannot be explained merely by the presence or absence of particular ErbB receptors and emphasizes the dynamic nature of the ErbB signaling system . The transcription factor approach developed here provides a gene economical route to the regulation of multiple genes and may be important …

Identification of a novel krueppel related zinc finger gene ( znf184 ) mapping to 6p21. (1997 May)
identification of a novel krueppel related zinc finger gene ( znf184 ) mapping to 6p21 . 3 . cDNA selection and exon trapping were performed on cosmids mapping to a region 3 Mb distal to HLA A . analysis of resulting fragments indicated the presence of two zinc finger transcripts , and one of these was used to isolate a partial cDNA ( znf184 ) from a placental library . The second transcript contained additional sequence of the 5 end of the gene , extending the sequence to 2678 bp . sequence analysis indicates that znf184 is a classical krueppel zinc finger with 19 highly conserved zinc finger motifs at the C terminus and a krueppel associated box at the N terminus of the protein . This gene encodes a 3 . 2 kb transcript that is highly expressed in testis and expressed at a moderate to low level in all other tissues tested . This zinc finger gene maps to a region approximately 200 kb distal to the microsatellite marker d6s105 and approximately 300 kb proximal to d6s1260 .

The biology of the mammalian krüppel like family of transcription factors. (2001 Jan)
The biology of the mammalian krüppel like family of transcription factors . recent advances in molecular cloning have led to the identification of a large number of mammalian zinc finger containing transcription factors that exhibit homology to the drosophila melanogaster protein , krüppel . although the amino acid sequences in the zinc finger domains of these krüppel like factors ( KLFs ) are closely related to one another , the regions outside the zinc fingers of the proteins are usually unique . KLFs display seemingly different and broad biological properties with each functioning as an activator of transcription , a repressor or both . This review article provides a current phylogenetic classification of the identified KLFs to date . More importantly , the currently known biological activities of the KLFs in regulating transcription , cell proliferation , differentiation and development are summarized and compared . further characterization of this interesting protein family should provide additional insights into the their respective regulatory role in various important biological processes .

Transcriptional activation by the papillomavirus E6 zinc finger oncoprotein. (1990 Jul)
transcriptional activation by the papillomavirus E6 zinc finger oncoprotein . The introduction of the bovine ( BPV ) or human papillomavirus E6 gene into susceptible cells can result in their transformation , but there are few clues to the mechanism of action of the E6 gene . The characteristic features of E6 proteins are their small size ( approximately 150 amino acids ) and the potential to form two large zinc fingers . To determine if E6 can function as a transcription factor , the BPV E6 gene was fused to the sequence specific DNA binding peptide encoded by the BPV E2 gene . This chimeric E6 E2 protein trans activated promoters that incorporated E2 binding elements in both rodent cells and saccharomyces cerevisiae . In the absence of E6 E2 localization to the target promoter , trans activation did not occur . alteration of the cysteine residues at the base of each finger abrogated the transcriptional activity of the E6 E2 hybrids . these data demonstrated that the BPV E6 gene encodes a transcription activation domain and imply that a specific structure of the protein , most likely the zinc fingers , is critical for this function . since these cysteine mutants are also transformation defective , E6 transcriptional functions may be required for its oncogenic activity .

The arabidopsis jagged gene encodes a zinc finger protein that promotes leaf tissue development. (2004 Feb)
The arabidopsis jagged gene encodes a zinc finger protein that promotes leaf tissue development . important goals in understanding leaf development are to identify genes involved in pattern specification , and also genes that translate this information into cell types and tissue structure . Loss of function mutations at the jagged ( JAG ) locus result in arabidopsis plants with abnormally shaped lateral organs including serrated leaves , narrow floral organs , and petals that contain fewer but more elongate cells . jag mutations also suppress bract formation in leafy , apetala1 and apetala2 mutant backgrounds . The JAG gene was identified by map based cloning to be a member of the zinc finger family of plant transcription factors and encodes a protein similar in structure to superman with a single C ( 2 ) H ( 2 ) type zinc finger , a proline rich motif and a short leucine rich repressor motif . JAG mRNA is localized to lateral organ primordia throughout the plant but is not found in the shoot apical meristem . misexpression of JAG results in leaf fusion and the development of ectopic leaf like outgrowth from both vegetative and floral tissues . Thus , JAG is necessary for proper lateral organ shape and is sufficient to induce the proliferation of lateral organ tissue .

The zinc finger of the CSN associated deubiquitinating enzyme usp15 is essential to rescue the E3 ligase Rbx1. (2005 Jul)
The zinc finger of the CSN associated deubiquitinating enzyme usp15 is essential to rescue the E3 ligase Rbx1 . The COP9 signalosome ( CSN ) is a conserved protein complex found in all eukaryotic cells and involved in the regulation of the ubiquitin ( Ub ) / 26S proteasome system . It binds numerous proteins , including the Ub E3 ligases and the deubiquitinating enzyme ubp12p , the S . pombe ortholog of human usp15 . We found that usp15 copurified with the human CSN complex . isolated CSN complex exhibited protease activity that deubiquitinated poly Ub substrates and was completely inhibited by o phenanthroline ( OPT ) , a metal chelating agent . surprisingly , the recombinant usp15 was also not able to cleave isopeptide bonds of poly Ub chains in presence of OPT . detailed analysis of USP sequences led to the discovery of a novel zinc ( Zn ) finger in usp15 and related USPs . mutation of a single conserved cysteine residue in the predicted Zn binding motif resulted in the loss of usp15 capability to degrade poly Ub substrates , indicating that the Zn finger is essential for the cleavage of poly Ub chains . moreover , pulldown experiments demonstrated diminished binding of tetra Ub to mutated usp15 . cotransfection of usp15 and the Ub ligase Rbx1 revealed that the wild type deubiquitinating enzyme , but not the usp15 mutant with a defective Zn finger , stabilized Rbx1 toward the Ub system , most likely …

Cloning , genomic organization and promoter activity of the mouse zinc finger protein gene ZF 12 The human zinc finger … (2003 Jun)
cloning , genomic organization and promoter activity of the mouse zinc finger protein gene ZF 12 The human zinc finger protein znf191 is a krüppel like transcription factor , which may be relevant to many diseases such as neuropsychiatric , cardiovascular and liver caner diseases . To elucidate the function of znf191 by gene targeting , it is necessary to clone and characterize of the homologous gene in model organisms ( mice ) . The mouse homologous gene ( ZF 12 ) was cloned and sequenced for the first time , the genbank accession number is ay052495 . It contains four exons and three introns ; all intronic splice sites exhibited consensus GT / AG sequences . The single nucleotide polymorphisms ( SNPs ) in exon 2 and the alternative length of 3 untranslated region ( 3 UTR ) have been found . The linkage of the ZF 12 gene and the zinc finger protein gene Zfp 35 has been found , so the ZF 12 gene can be localized to B3 to C or beside of chromosome 18 . We assessed approximately 1 . 2 kb of 5 flanking region of the ZF 12 gene for basal promoter activity . A series of deletion mutants of 5 flanking region linked to the luciferase gene was constructed . basal level expression of these constructs was tested in COS 7 cells , nih3t3 cells and HeLa cells . By measuring luciferase activity , which was transiently expressed in the transfected cells …

Cloning and characterization of a sulphite resistance gene of saccharomyces cerevisiae. (1995 Jan)
cloning and characterization of a sulphite resistance gene of saccharomyces cerevisiae . In this paper we describe the cloning and sequencing of the gene ( SUL1 ) responsible for sulphite resistance in a saccharomyces cerevisiae mutant ( casalone et al . , 1992 ) . The deduced amino acid sequence predicted that the gene codes for a zinc finger protein with five fingers . comparison of wild type and mutant gene sequences demonstrated that the mutation event was a transversion from C to G ; as a consequence of the mutation a histidine substituted an aspartic acid , affecting directly the fourth finger structure . The SUL1 gene sequence corresponds to that of FZF1 gene ( breitwieser et al . , 1993 ) to which no function was attributed .

Activation of the zinc finger encoding gene krox 20 in adult rat brain : comparison with zif268. (1992 Jun)
activation of the zinc finger encoding gene krox 20 in adult rat brain : comparison with zif268 . zif268 and krox 20 are transcription regulatory factors that contain highly homologous zinc finger DNA binding domains . recent studies have demonstrated that zif268 expression is rapidly regulated in brain by neuronal stimulation . We now report that , like zif268 , krox 20 is rapidly and transiently activated by electroconvulsive shock treatment ( ECT ) , D1 dopamine receptor activation , and opiate withdrawal . these studies indicate that , as found for the leucine zipper family of transcription factors , multiple members of the zinc finger family of transcription factors are induced by neuronal stimulation .

Why zinc fingers prefer zinc : ligand field symmetry and the hidden thermodynamics of metal ion selectivity. (2004 Nov)
Why zinc fingers prefer zinc : ligand field symmetry and the hidden thermodynamics of metal ion selectivity . The zinc finger , a motif of protein nucleic acid recognition broadly conserved among eukaryotes , is a globular minidomain containing a tetrahedral metal binding site . preferential coordination of Zn ( 2 ) ( relative to Co ( 2 ) ) is proposed to reflect differences in ligand field stabilization energies ( lfses ) due to complete or incomplete occupancy of d orbitals . LFSE predicts that the preference for Zn ( 2 ) should be purely enthalpic in accord with calorimetric studies of a high affinity consensus peptide ( CP 1 ; blasie , C . A . , and Berg , J . ( 2002 ) biochemistry 41 , 15068 73 ) . despite its elegance , the general predominance of LFSE is unclear as ( i ) the magnitude by which CP 1 prefers Zn ( 2 ) is greater than that expected and ( ii ) the analogous metal ion selectivity of a zinc metalloenzyme ( carbonic anhydrase ) is driven by changes in entropy rather than enthalpy . because CP 1 was designed to optimize zinc binding , we have investigated the NMR structure and metal ion selectivity of a natural finger of lower stability derived from human tumor suppressor protein WT1 . raman spectroscopy suggests that the structure of the WT1 domain is unaffected by interchange of Zn ( 2 ) and Co ( 2 …

Isolation and characterisation of a diverse family of arabidopsis two and three fingered C2H2 zinc finger protein genes and cdnas. (1997 Apr)
isolation and characterisation of a diverse family of arabidopsis two and three fingered C2H2 zinc finger protein genes and cdnas . In animal systems the C2H2 zinc finger protein ( ZFP ) gene family is the largest group of regulatory proteins and its members have a wide and important role in growth and development . It is likely that this family of ZFP transcription factors will also be important in plants . We have used a PCR approach employing highly degenerate oligonucleotide primers to isolate several arabidopsis genomic and cDNA clones encoding potential ZFPs . In addition we have used the sequence information from these clones to identify two ESTs as members of this family . Five two fingered and one three fingered ZFPs have been identified . outside of the zinc finger regions , there is considerable sequence diversity , including the sequence and length of the interfinger region ; the expression pattern of each gene is different . This is the first report of the isolation of a three fingered plant C2H2 ZFP gene and we discuss its possible evolutionary origin from two fingered ZFP genes .

Synthetic zinc finger peptides : old and novel applications. (2004 Jul)
synthetic zinc finger peptides : old and novel applications . In the last decade , the efforts in clarifying the interaction between zinc finger proteins and DNA targets strongly stimulated the creativity of scientists in the field of protein engineering . In particular , the versatility and the modularity of zinc finger ( ZF ) motives make these domains optimal building blocks for generating artificial zinc finger peptides ( ZFPs ) . ZFPs can act as transcription modulators potentially able to control the expression of any desired gene , when fused to an appropriate effector domain . artificial ZFPs open the possibility to re program the expression of specific genes at will and can represent a powerful tool in basic science , biotechnology and gene therapy . In this review we will focus on old , novel and possible future applications of artificial ZFPs .

Specific interactions of the autoantigen L7 with multi zinc finger protein ZNF7 and ribosomal protein S7. (1997 Oct)
specific interactions of the autoantigen L7 with multi zinc finger protein ZNF7 and ribosomal protein S7 . The eucaryotic protein L7 , which associates with the large subunit of ribosomes , has been shown to be a major autoantigen in systemic autoimmune arthritis . The N terminus carries a sequence motif that is similar to the leucine zipper domain of eucaryotic transcription factors . This domain promotes the homodimerization of protein L7 through alpha helical coiled coil formation and binds to distinct mrnas , thereby inhibiting their cell free translation . using a yeast two hybrid selection , we have identified from a jurkat T lymphoma cDNA library ribosomal protein S7 and the multi zinc finger protein ZNF7 as proteins that interact with protein L7 . A fragment of L7 carrying the leucine zipper like domain is fully sufficient to mediate these interactions . their potential biological significance is indicated by low apparent dissociation constants of S7 L7 ( 15 x 10 ( 9 ) M ) and , respectively , ZNF7 L7 ( 2 x 10 ( 9 ) M ) complexes and co immunoprecipitation of proteins S7 , ZNF7 , and L7 from a cell lysate with an anti L7 antibody . We also show that ZNF7 like L7 and S7 can exist in a ribosome bound form . This study provides further evidence suggesting that L7 is involved in translational regulation through interactions with components of the translational apparatus .

Combining structure based design with phage display to create new Cys ( 2 ) His ( 2 ) zinc finger … (2000 Oct)
combining structure based design with phage display to create new Cys ( 2 ) His ( 2 ) zinc finger dimers . background : several strategies have been reported for the design and selection of novel DNA binding proteins . Most of these studies have used Cys ( 2 ) His ( 2 ) zinc finger proteins as a framework , and have focused on constructs that bind DNA in a manner similar to zif268 , with neighboring fingers connected by a canonical ( krüppel type ) linker . This linker does not seem ideal for larger constructs because only modest improvements in affinity are observed when more than three fingers are connected in this manner . Two strategies have been described that allow the productive assembly of more than three canonically linked fingers on a DNA site : connecting sets of fingers using linkers ( covalent ) , or assembling sets of fingers using dimerization domains ( non covalent ) . results : using a combination of structure based design and phage display , we have developed a new dimerization system for Cys ( 2 ) His ( 2 ) zinc fingers that allows the assembly of more than three fingers on a desired target site . Zinc finger constructs employing this new dimerization system have high affinity and good specificity for their target sites both in vitro and in vivo . constructs that recognize an asymmetric binding site as heterodimers can be obtained through substitutions in the zinc …

DNA target selectivity by the vitamin D3 receptor : mechanism of dimer binding to an asymmetric repeat element. (1993 Aug)
DNA target selectivity by the vitamin D3 receptor : mechanism of dimer binding to an asymmetric repeat element . The 1 , 25 dihydroxyvitamin D3 receptor , like other members of the nuclear receptor superfamily , forms dimers in solution that are probably stabilized by a dyad symmetrical interface formed by the ligand binding domain . This receptor , however , recognizes DNA targets that are not dyad symmetric but rather are organized as direct repeats of a hexameric sequence with a characteristic 3 bp spacing . using molecular modeling and site directed mutagenesis , we have identified regions within the vitamin D3 receptor zinc finger region that confer selectivity for direct repeats with appropriate spacing . reflecting the organization of the DNA target , these regions , mapping to the tip of the first zinc finger module and the N and C termini of the second finger module , direct asymmetrical protein protein contacts . A stereochemical model is proposed for these interactions .

Mizip , a highly conserved , vertebrate specific melanin concentrating hormone receptor 1 interacting zinc finger protein. (2002 Sep)
mizip , a highly conserved , vertebrate specific melanin concentrating hormone receptor 1 interacting zinc finger protein . using the yeast two hybrid system a novel protein was identified from human brain that interacts with the C terminus of melanin concentrating hormone receptor 1 ( MCH R1 ) . This protein , characterized by a myeloid translocation protein 8 , nervy , deaf1 proteins ( MYND ) zinc finger domain , is termed MCH R1 interacting zinc finger protein , mizip . It is fully conserved in man , rat , mouse and highly conserved in xenopus and zebrafish , but not detectable in invertebrates . mizip gene organization in human ( six exons on chromosome 9q34 . 3 ) and mouse is highly conserved , yet in rodents an additional exon is generated giving rise to alternatively spliced mrnas . mizip is expressed in brain , testis and stomach , where expression of MCH and MCH R1 was previously reported . mizip interaction with MCH R1 was verified by overlay and pull down assays as well as by co transfection experiments in human embryonic kidney 293 cells . mizip is cytoplasmically localized but gets recruited to the plasma membrane when cells are co transfected with MCH R1 supporting the notion that mizip is involved in the function of MCH R1 .

Early hematopoietic zinc finger protein zinc finger protein 521 : a candidate regulator of diverse immature cells. (2008 Mar)
early hematopoietic zinc finger protein zinc finger protein 521 : a candidate regulator of diverse immature cells . The early hematopoietic zinc finger protein / zinc finger protein 521 ( EHZF / znf521 ) is a recently identified , 1131 amino acid long nuclear factor that contains 30 zinc fingers distributed in clusters throughout its sequence . A 13 AA motif , that binds to components of the nuclear remodelling and histone deacetylation ( NuRD ) complex and is conserved in several trascriptional co repressors , is located at the amino terminal end of the molecule . EHZF / znf521 expression is high in the most immature cells of the haematopoietic system and declines with differentiation . Its transcript is also abundant in brain , particularly in the cerebellum . Its murine counterpart , Evi3 / zfp521 , is enriched in haematopoietic and neural stem cells , in cerebellar granule neuron precursors and in the developing striatum . enforced expression of EHZF / znf521 in haematopoietic progenitors results in their expansion and in inhibition of differentiation . EHZF / znf521 is a member of the BMP signalling pathway and an inhibitor of the transcription factor OLF1 / EBF1 , implicated in the differentiation of neural progenitors and in the specification of the B cell lineage . EHZF expression is observed in most acute myelogenous leukaemias and is particularly high in those with rearrangements of the MLL gene , where EHZF may contribute to the leukaemic phenotype . EHZF / znf521 …

Gene regulation in planta by plant derived engineered zinc finger protein transcription factors. (2005 Apr)
Gene regulation in planta by plant derived engineered zinc finger protein transcription factors . The ability to modify plant traits is of great commercial potential in agricultural biotechnology . To this end we have engineered plant based zinc finger protein transcription factors ( ZFP TFs ) that minimize the use of non plant DNA sequences . This novel architecture supports the use of tandem arrays of zinc finger DNA recognition domains such that the ZFP TF binds a contiguous DNA target site thus emulating the design of ZFP TFs described previously for mammalian gene regulation . We show that this plant based ZFP TF architecture supports high affinity DNA binding while allowing the specificity of the DNA protein interaction to be determined by the amino acid sequences of the recognition helices . This plant based backbone thus supports the use of previously characterized DNA recognition helices originally identified in a mammalian ZFP context without using mammalian DNA sequences . moreover , we show that plant based ZFP TFs employing this new architecture can up regulate endogenous ADH activity by 20 fold in transgenic arabidopsis . Thus plant based ZFP TFs are shown to be potent regulators of gene expression in vivo .

LOS2 , a genetic locus required for cold responsive gene transcription encodes a bi functional enolase. (2002 May)
LOS2 , a genetic locus required for cold responsive gene transcription encodes a bi functional enolase . The arabidopsis mutation , los2 , impairs cold responsive gene transcription , acquired freezing tolerance and plant resistance to chilling under certain conditions . LOS2 was isolated through positional cloning and shown to encode an enolase in the glycolytic pathway . In animal cells , enolase has also been known to function as a transcription factor that represses the expression of c myc by binding to the c myc gene promoter . LOS2 fused to green fluorescent protein is targeted to the nucleus as well as to the cytoplasm . LOS2 / enolase protein can bind to the cis element of the human c myc gene promoter and to the gene promoter of STZ / zat10 , a zinc finger transcriptional repressor from arabidopsis . STZ / zat10 expression is induced rapidly and transiently by cold in the wild type , and this induction is stronger and more sustained in the los2 mutant . furthermore , the expression of a rd29a LUC reporter gene is repressed significantly by STZ / zat10 in transient expression assays in arabidopsis leaves . Our results demonstrate that cold responsive gene transcription in plants is controlled by a bi functional enolase .