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 .

Genomic organisation and characterisation of the neural sex determination gene fruitless ( fru ) in the hawaiian species drosophila heteroneura. (2000 May)
genomic organisation and characterisation of the neural sex determination gene fruitless ( fru ) in the hawaiian species drosophila heteroneura . there are several mechanisms for the determination of sex . sexual behaviour is part of the sex determination cascade , and in drosophila melanogaster male courtship is controlled in part by the fruitless gene . As part of a study of sexual behaviour in hawaiian drosophila , we have cloned the neural sex determination gene fru from the hawaiian picture wing species drosophila heteroneura . The fru gene has at least seven exons covering a region of 18kb and encodes three transcripts , fruA , fruB and fruC . Each transcript encodes a single ORF of 841 , 678 and 691aa , respectively . The FRUA and FRUB proteins have a BTB protein protein binding domain and two zinc finger like domains and are well conserved with the D . melanogaster proteins . The FRUC protein has a BTB domain but no zinc finger like domains . The fru gene is expressed in 1 7 day old adult males as a 5 . 1kb transcript . This transcript is not seen in adult females , so the fru gene has a different pattern of sex differential expression in the hawaiian drosophila compared with D . melanogaster .

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 .

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 …

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 .

CDNA cloning , DNA binding , and evolution of mammalian transcription factor IIIA. (2002 Jan)
cDNA cloning , DNA binding , and evolution of mammalian transcription factor IIIA . cDNA for rat transcription factor IIIA ( tfiiia ) was cloned by degenerate PCR and rapid amplification of cDNA ends . This cDNA coded for a protein with nine Cys ( 2 ) His ( 2 ) zinc fingers and a non finger C terminal tail ; 63 amino acid ( aa ) sequence identity was observed with the xenopus tfiiia zinc finger region . recombinant rat protein containing only the nine fingers afforded dnase I protection of the identical nucleotides protected by xenopus laevis native tfiiia on the xenopus 5S RNA gene internal control region . A putative mouse tfiiia clone was identified in an expressed sequence tag database by sequence similarity to rat tfiiia . recombinant nine finger protein from this clone afforded dnase I protection of the xenopus 5S rRNA gene like the native frog protein as did a recombinant nine finger form of a putative human tfiiia clone . these DNA binding results demonstrate that these clones code for the respective mammalian tfiiias . rodent and human tfiiias share about 87 aa sequence identity in their zinc finger regions and have evolved to about the same extent as X . laevis and xenopus borealis tfiiias . A monoclonal antibody against human p53 tumor suppressor bound to rat and mouse tfiiia but not to human tfiiia in western blots . The N terminal regions of rodent and human tfiiia do not contain the …

Identification of DNA recognition sequences and protein interaction domains of the multiple Zn finger protein Roaz. (1998 Nov)
identification of DNA recognition sequences and protein interaction domains of the multiple Zn finger protein Roaz . Roaz , a rat C2H2 zinc finger protein , plays a role in the regulation of olfactory neuronal differentiation through its interaction with the Olf 1 / EBF transcription factor family . An additional role for the Roaz / Olf 1 / EBF heterodimeric protein is suggested by its ability to regulate gene activation at a distinct promoter lacking Olf 1 / EBF binding sites . using an in vitro binding site selection assay ( selex ) , we demonstrate that Roaz protein binds to novel inverted perfect or imperfect repeats of gcaccc separated by 2 bp . We show that Roaz is capable of binding to a canonical consensus recognition sequence with high affinity ( Kd 3 nM ) . analysis of the structural requirement for protein dimerization and DNA binding by Roaz reveals the role of specific zinc finger motifs in the Roaz protein for homodimerization and heterodimerization with the Olf 1 / EBF transcription factor . The DNA binding domain of Roaz is mapped to the N terminal 277 amino acids , containing the first seven zinc finger motifs , which confers weak monomeric binding to a single half site and a stronger dimeric binding to the inverted repeat in a binding site dependent manner . Full length protein can form dimers on both the inverted repeat and direct repeat but not on a single half site . these findings …

Metal and DNA binding properties and mutational analysis of the transcription activating factor , B , of coliphage 186 : … (1997 Aug)
metal and DNA binding properties and mutational analysis of the transcription activating factor , B , of coliphage 186 : a prokaryotic C4 zinc finger protein . coliphage 186 B is a 72 amino acid protein belonging to the Ogr family of analogous transcription factors present in P2 like phage , which contain a Cys X2 Cys X22 Cys X4 Cys presumptive zinc finger motif . The molecular characterization of these proteins has been hampered by their insolubility , a difficulty overcome in the present study by obtaining B as a soluble cadmium containing derivative ( CdB ) . atomic absorption spectroscopy showed the presence of one atom of cadmium per molecule of purified CdB . The UV absorption spectrum revealed a shoulder at 250 nm , characteristic of CysS Cd ( II ) ligand to metal charge transfer transitions , and the difference absorption coefficient after acidification ( delta epsilon 248 , 24 mM 1 cm 1 ) indicated the presence of a Cd ( Cys S ) 4 center . Gel mobility shift analysis of CdB with a 186 late promoter demonstrated specific DNA binding ( KD , app 3 4 microm ) and the protein was shown to activate transcription in vitro from a promoter reporter plasmid construct . The B DNA binding site was mapped by gel shift and dnaase I cleavage protection experiments to an area between 70 and 43 relative to the transcription start site , coincident with the consensus sequence , gttgt N8 …

A zinc finger like domain in the 54kda protein of several pestiviruses. (1997 Jul)
A zinc finger like domain in the 54kda protein of several pestiviruses .

Variations of the C2H2 zinc finger motif in the yeast genome and classification of yeast zinc finger proteins. (1997 Jul)
variations of the C2H2 zinc finger motif in the yeast genome and classification of yeast zinc finger proteins . The prosite pattern Zinc finger C2H2 was extended to permit the detection of all C2H2 zinc fingers and their parent proteins in the recently completed sequence of the yeast genome . additionally , a new computer program was written that extracts other zinc binding motifs ( non C2H2 fingers ) , overlapping with the classical zinc finger pattern , from the found set of yeast C2H2 fingers . The complete and correct detection of all fingers is a prerequisite for the classification of the yeast zinc finger proteins in functional terms . The detected 53 yeast C2H2 zinc finger proteins do not contain finger clusters with 10 or more repeats , as is frequently found in higher eukaryotes . Only three proteins contain four or more fingers in a cluster . moreover , nearly all 27 yeast proteins with tandem arrays of two or three finger domains can be classified into nine subgroups with high sequence conservation in their finger clusters , in particular of their DNA recognition helices . these results and application of the recently elaborated finger / DNA recognition rules suggest that the yeast proteins belonging to the same subgroup may recognize identical or very similar DNA sites .

A novel human striated muscle RING zinc finger protein , SMRZ , interacts with smt3b via its RING domain. (2001 Jun)
A novel human striated muscle RING zinc finger protein , SMRZ , interacts with smt3b via its RING domain . The RING domain is a conserved zinc finger motif , which serves as a protein protein interaction interface . searches of a human heart expressed sequence tag data base for genes encoding the RING domain identified a novel cDNA , named striated muscle RING zinc finger protein ( SMRZ ) . The SMRZ cDNA is 1 . 9 kilobase pairs in length and encodes a polypeptide of 288 amino acid residues ; analysis of the peptide sequence demonstrated an N terminal RING domain . fluorescence in situ hybridization localized SMRZ to chromosome 1p33 34 . northern blots demonstrated that SMRZ is expressed exclusively in striated muscle . In the cardiovascular system , SMRZ is more highly expressed in the fetal heart than in the adult heart ( slightly higher expression in the ventricle than in the atrium ) , suggesting that SMRZ is developmentally regulated . SMRZ was found to interact with smt3b , a ubiquitin like protein , through the SMRZ RING domain . This interaction was abolished by mutagenesis of conserved RING domain residues . transient transfection of SMRZ into c2c12 myoblasts showed localization of SMRZ to the nucleus . these data suggest that SMRZ may play an important role in striated muscle cell embryonic development and perhaps in cell cycle regulation .

Znf268 , a novel kruppel like zinc finger protein , is implicated in early human liver development. (2004 Nov)
znf268 , a novel kruppel like zinc finger protein , is implicated in early human liver development . The advancement in gene knockout and transgenesis have brought about enormous improvement in our understanding of mouse embryogenesis in the past decade or so . On the other hand , relatively little is known about human embryogenesis due largely to the lack of easy access to human embryos and tissues for biomedical studies . We have previously isolated a novel zinc finger gene , znf268 , from a 3 week old human embryo cDNA library in an effort to identify genes important for human embryonic development . To investigate the potential involvement of znf268 in human embryogenesis , we report here the spatial and temporal regulation of its expression during development . northern blot and western blot analyses revealed that znf268 is expressed in early embryos , predominantly , if not exclusively , in fetal liver with little detectable expression in other fetal organs . interestingly , unlike most zinc finger proteins , znf268 protein was found to be localized mainly in the cytoplasm of embryonic hepatocytes . This subcellular localization was substantiated by the localization of EGFP znf268 fusion protein overexpressed in the transfected COS7 cells . these results suggest that znf268 plays a role in early human liver development most likely by functioning through a cytoplasmic mechanism .

Zinc : biochemistry , physiology , toxicology and clinical pathology. (1989 Oct)
Zinc : biochemistry , physiology , toxicology and clinical pathology . among the transition and group II elements the abundance of zinc in biology is second only to that of iron . It is present in and indispensable to all forms of life . knowledge regarding the biological occurrence and function of zinc , the development of methods that permit its detection and those aspects of biochemistry which have allowed an appreciation of the manner in which it participates in generating biological specificity have grown exponentially in the last two decades . The recognition that zinc is an essential , coenzyme like component of many enzymes , indispensable to their function , is reminiscent of the role of some vitamins . technical advances in the isolation and characterization of enzymes in general and metalloenzymes in particular were basic to the rapid growth of zinc metallobiochemistry during the last two decades . Zinc is now known to be an integral component of a large variety of proteins and enzymes and , hence , the total zinc content of tissues cannot serve as a guide to the multiple functions of the metal . Zinc participates in a wide variety of metabolic processes including carbohydrate , lipid , protein and nucleic acid synthesis or degradation . Most recently , zinc proteins have been shown to be involved in the transcription and translation of the genetic material , perhaps accounting for its essentiality to all forms of life . A number of zinc proteins …

From repression domains to designer zinc finger proteins : a novel strategy of intracellular immunization against HIV. (1996 Oct)
From repression domains to designer zinc finger proteins : a novel strategy of intracellular immunization against HIV . tissue specific gene regulation of eukaryotic organisms is to a large extent mediated by transcription factors that interact with genomic DNA sequences in a sequence specific manner . The purpose of this synopsis is to put forward the potential of designer zinc finger proteins in treating infections of human immunodeficiency virus ( HIV ) . artificial transcription factors containing designer zinc finger structures fused to activator or repressor domains have been designated transcription response modifiers ( TRMs ) . The principle of engineering TRMs has been derived from the analysis of human krüppel type zinc finger genes and their products . Our research efforts encompass two fascinating features that are displayed by the human krüppel type zinc finger protein KOX1 : 1 ) the krüppel type zinc finger domains display rules of sequence specific DNA recognition , and 2 ) the evolutionarily conserved krüppel associated box ( KRAB ) presents one of the strongest transcriptional repressors identified so far in mammalian organisms . The KRAB repressor activity is postulated to be mediated through co repressor molecules , such as silencing mediating protein 1 ( SMP 1 ) . Thus , the structural organization and functional analysis of zinc finger proteins revealed principles of zinc finger transcription factors that are applicable for reducing the viral load in individuals infected with HIV . In this article , a novel concept of generating therapeutic proteins …

High levels of zinc ions induce loss of mitochondrial potential and degradation of antiapoptotic Bcl 2 protein in in vitro … (2001 Feb)
High levels of zinc ions induce loss of mitochondrial potential and degradation of antiapoptotic Bcl 2 protein in in vitro cultivated human prostate epithelial cells . prostate epithelial cells contain the highest levels of zinc among all organs and tissues in the human body . Zinc is accumulated primarily in the mitochondria , where it is responsible for inhibition of mitochondrial aconitase activity , thereby increasing citrate production . The present study was designed to clarify the role of zinc for human prostate epithelial cell growth and apoptosis . apoptosis of in vitro cultivated human prostate epithelial cells exposed to ZnCl ( 2 ) was analyzed by determination of phospholipid membrane asymmetry , nuclear fragmentation , DNA strand breaks , changes of mitochondrial potential and cellular pro / antiapoptotic proteins . Zinc induced apoptosis without involvement of p53 by decreasing mitochondrial transmembrane potential ( deltapsi ( m ) ) and Bcl 2 protein levels in proliferating epithelial cells . Thus , the high local concentrations of zinc ions in the prostatic lumen seem to be necessary to regulate proliferative activities and to enforce epithelial differentiation processes .