scholarly journals The zinc finger proteins ZC3H20 and ZC3H21 stabilise mRNAs encoding membrane proteins and mitochondrial proteins in insect-formTrypanosoma brucei

2019 ◽  
Author(s):  
Bin Liu ◽  
Kevin Kamanyi Marucha ◽  
Christine Clayton
Keyword(s):  
Zinc Finger ◽  
Developmental Regulation ◽  
Specific Protein ◽  
Mitochondrial Proteins ◽  
Tsetse Flies ◽  
Dynamic Regulation ◽  
Target Mrnas ◽  
Zinc Finger Motifs ◽  
Specific Proteins ◽  
Stumpy Form

SummaryZC3H20 and ZC3H21 are related trypanosome proteins with two C(x)8C(x)5C(x)3H zinc finger motifs. ZC3H20 is unstable in mammalian-infective bloodstream forms, but becomes more abundant as they transform to growth-arrested stumpy form, while ZC3H21 appears only in the procyclic form of the parasite, which infects Tsetse flies. Each protein binds to several hundred mRNAs, with overlapping but not identical specificities. Both increase expression of bound mRNAs, probably through recruitment of the MKT1-PBP1 complex. At least seventy of the bound mRNAs decrease after RNAi targeting ZC3H20 or ZC3H20 and ZC3H21; their products include procyclic-specific proteins of the plasma membrane and energy metabolism. Simultaneous depletion of ZC3H20 and ZC3H21 causes procyclic forms to shrink and stop growing; in addition to decreases in target mRNAs, there are other changes suggestive of loss of developmental regulation. The bloodstream-form specific protein RBP10 controls ZC3H20 and ZC3H21 expression. Interestingly, some ZC3H20/21 target mRNAs also bind to and are repressed by RBP10, allowing for dynamic regulation as RBP10 decreases and ZC3H20 and ZC3H21 increase during differentiation.

The Only Function of Grauzone Required for Drosophila Oocyte Meiosis Is Transcriptional Activation of the cortex Gene

Genetics ◽  
2000 ◽  
Vol 155 (4) ◽  
pp. 1831-1839
Author(s):  
Emily Harms ◽  
Tehyen Chu ◽  
Gwénola Henrion ◽  
Sidney Strickland
Keyword(s):  
Zinc Finger ◽  
Transcriptional Activation ◽  
Single Amino Acid ◽  
Primary Role ◽  
Extra Copy ◽  
Oocyte Meiosis ◽  
Zinc Finger Motifs ◽  
High Level ◽  
Transcriptional Pathway

Abstract The grauzone and cortex genes are required for the completion of meiosis in Drosophila oocytes. The grauzone gene encodes a C2H2-type zinc-finger transcription factor that binds to the cortex promoter and is necessary for high-level activation of cortex transcription. Here we define the region of the cortex promoter to which Grauzone binds and show that the binding occurs through the C-terminal, zinc-finger-rich region of the protein. Mutations in two out of the five grauzone alleles result in single amino acid changes within different zinc-finger motifs. Both of these mutations result in the inability of Grauzone to bind DNA effectively. To determine the mechanism by which Grauzone regulates meiosis, transgenic flies were produced with an extra copy of the cortex gene in homozygous grauzone females. This transgene rescued the meiosis arrest of embryos from these mutants and allowed their complete development, indicating that activation of cortex transcription is the primary role of Grauzone during Drosophila oogenesis. These experiments further define a new transcriptional pathway that controls the meiotic cell cycle in Drosophila oocytes.

ATBF1, a multiple-homeodomain zinc finger protein, selectively down-regulates AT-rich elements of the human alpha-fetoprotein gene

1994 ◽  
Vol 14 (2) ◽  
pp. 1395-1401
Author(s):  
H Yasuda ◽  
A Mizuno ◽  
T Tamaoki ◽  
T Morinaga
Keyword(s):  
Zinc Finger ◽  
Zinc Finger Protein ◽  
Human Albumin ◽  
Alpha Fetoprotein ◽  
Promoter Regions ◽  
Expression Plasmid ◽  
Zinc Finger Motifs ◽  
Transcriptional Regulatory ◽  
Cat Gene ◽  
Afp Promoter

ATBF1 is a 306-kDa protein containing four homeodomains, 17 zinc finger motifs, and several segments potentially involved in transcriptional regulation (T. Morinaga, H. Yasuda, T. Hashimoto, K. Higashio, and T. Tamaoki, Mol. Cell. Biol. 11:6041-6049, 1991). At least one of the homeodomains of ATBF1 binds to an AT-rich element in the human alpha-fetoprotein (AFP) enhancer (enhancer AT motif). In the present work, we analyzed the transcriptional regulatory activity of ATBF1 with respect to the enhancer AT motif and similar AT-rich elements in the human AFP promoter and the human albumin promoter and enhancer. Gel retardation assays showed that ATBF1 binds to the AFP enhancer AT motif efficiently; however, it binds weakly or not at all to other AT-rich elements in the AFP and albumin regulatory regions studied. Alterations of the enhancer AT motif by site-specific mutagenesis resulted in the loss of binding of ATBF1. Cotransfection experiments with an ATBF1 expression plasmid and the chloramphenicol acetyltransferase (CAT) gene fused to AFP promoter or enhancer fragments showed that ATBF1 suppressed the activity of AFP enhancer and promoter regions containing AT-rich elements. This suppression was reduced when the mutated AT motifs with low affinity to ATBF1 were linked to the CAT gene. The ATBF1 suppression of AFP promoter and enhancer activities appeared to be due, at least in part, to competition between ATBF1 and HNF1 for the same binding site. In contrast to the AFP promoter and enhancer, the albumin promoter and enhancer were not affected by ATBF1, although they contain homologous AT-rich elements. These results show that ATBF1 is able to distinguish AFP and albumin AT-rich elements, leading to selective suppression of the AFP promoter and enhancer activities.

scholarly journals Generation of asymmetry during development. Segregation of type-specific proteins in Caulobacter.

1979 ◽  
Vol 81 (1) ◽  
pp. 123-136 ◽  
Author(s):  
N Agabian ◽  
M Evinger ◽  
G Parker
Keyword(s):  
Cell Cycle ◽  
Cell Division ◽  
Messenger Rna ◽  
Cell Types ◽  
Specific Protein ◽  
Soluble Proteins ◽  
Specific Cell ◽  
Daughter Cells ◽  
Specific Proteins ◽  
Entire Cell

An essential event in developmental processes is the introduction of asymmetry into an otherwise undifferentiated cell population. Cell division in Caulobacter is asymmetric; the progeny cells are structurally different and follow different sequences of development, thus providing a useful model system for the study of differentiation. Because the progeny cells are different from one another, there must be a segregation of morphogenetic and informational components at some time in the cell cycle. We have examined the pattern of specific protein segregation between Caulobacter stalked and swarmer daughter cells, with the rationale that such a progeny analysis would identify both structurally and developmentally important proteins. To complement the study, we have also examined the pattern of protein synthesis during synchronous growth and in various cellular fractions. We show here, for the first time, that the association of proteins with a specific cell type may result not only from their periodicity of synthesis, but also from their pattern of distribution at the time of cell division. Several membrane-associated and soluble proteins are segregated asymmetrically between progeny stalked and swarmer cells. The data further show that a subclass of soluble proteins becomes associated with the membrane of the progeny stalked cells. Therefore, although the principal differentiated cell types possess different synthetic capabilities and characteristic proteins, the asymmetry between progeny stalked and swarmer cells is generated primarily by the preferential association of specific soluble proteins with the membrane of only one daughter cell. The majority of the proteins which exhibit this segregation behavior are synthesized during the entire cell cycle and exhibit relatively long, functional messenger RNA half-lives.

scholarly journals Photoreceptor Compartment-Specific TULP1 Interactomes

2021 ◽  
Author(s):  
Lindsey A Ebke ◽  
Satyabrata Sinha ◽  
Gayle JT Pauer ◽  
Stephanie A Hagstrom
Keyword(s):  
Molecular Motors ◽  
Protein Trafficking ◽  
Specific Interaction ◽  
Specific Protein ◽  
Vesicle Recycling ◽  
Binding Partners ◽  
Skeletal Protein ◽  
Liquid Chromatography Tandem Mass ◽  
In The Wild ◽  
Specific Proteins

Photoreceptors are highly compartmentalized cells with large amounts of proteins synthesized in the inner segment (IS) and transported to the outer segment (OS) and synaptic terminal. Tulp1 is a photoreceptor-specific protein localized to the IS and synapse. In the absence of Tulp1, sev-eral OS-specific proteins are mislocalized and synaptic vesicle recycling is impaired. To better understand the involvement of Tulp1 in protein trafficking, our approach was to physically iso-late Tulp1-containing photoreceptor compartments by serial tangential sectioning of retinas and to identify compartment-specific Tulp1 binding partners by immunoprecipitation followed by liquid chromatography tandem mass spectrometry. Our results indicate that Tulp1 has two dis-tinct interactomes. We report the identification of: 1) an IS-specific interaction between Tulp1 and the motor protein Kinesin family member 3a (Kif3a), 2) a synaptic-specific interaction be-tween Tulp1 and the scaffold protein Ribeye, and 3) an interaction between Tulp1 and the cyto-skeletal protein Microtubule-associated protein 1B (MAP1B) in both compartments. Immuno-localization studies in the wild-type retina indicate that Tulp1 and its binding partners co-localize to their respective compartments. Our observations are compatible with Tulp1 functioning in protein trafficking in multiple photoreceptor compartments, likely as an adapter molecule linking vesicles to molecular motors and the cytoskeletal scaffold.

scholarly journals The L1Tc C-Terminal Domain from Trypanosoma cruzi Non-Long Terminal Repeat Retrotransposon Codes for a Protein That Bears Two C2H2 Zinc Finger Motifs and Is Endowed with Nucleic Acid Chaperone Activity

2005 ◽  
Vol 25 (21) ◽  
pp. 9209-9220 ◽  
Author(s):  
Sara R. Heras ◽  
Manuel C. López ◽  
José Luis García-Pérez ◽  
Sandra L. Martin ◽  
M. Carmen Thomas
Keyword(s):  
Nucleic Acid ◽  
Trypanosoma Cruzi ◽  
Long Terminal Repeat ◽  
Zinc Finger ◽  
Chaperone Activity ◽  
Terminal Repeat ◽  
Duplex Dna ◽  
Long Terminal Repeat Retrotransposon ◽  
Nucleic Acid Chaperone ◽  
Zinc Finger Motifs

ABSTRACT L1Tc, a non-long terminal repeat retrotransposon from Trypanosoma cruzi, is a 4.9-kb actively transcribed element which contains a single open reading frame coding for the machinery necessary for its autonomous retrotransposition. In this paper, we analyze the protein encoded by the L1Tc 3′ region, termed C2-L1Tc, which contains two zinc finger motifs similar to those present in the TFIIIA transcription factor family. C2-L1Tc binds nucleic acids with different affinities, such that RNA > tRNA > single-stranded DNA > double-stranded DNA, without any evidence for sequence specificity. C2-L1Tc also exhibits nucleic acid chaperone activity on different DNA templates that may participate in the mechanism of retrotransposition of the element. C2-L1Tc promotes annealing of complementary oligonucleotides, prevents melting of perfect DNA duplexes, and facilitates the strand exchange between DNAs to form the most stable duplex DNA in competitive displacement assays. Mapping of regions of C2-L1Tc using specific peptides showed that nucleic acid chaperone activity required a short basic sequence accompanied by a zinc finger motif or by another basic region such as RRR. Thus, a short basic polypeptide containing the two C2H2 motifs promotes formation of the most stable duplex DNA at a concentration only three times higher than that required for C2-L1Tc.

scholarly journals Developmental regulation of specific protein interactions with an enhancerlike binding site far upstream from the avian very-low-density apolipoprotein II gene.

1990 ◽  
Vol 10 (1) ◽  
pp. 154-164 ◽  
Author(s):  
P A Hoodless ◽  
R N Roy ◽  
A K Ryan ◽  
R J Haché ◽  
M Z Vasa ◽  
...  
Keyword(s):  
Protein Interactions ◽  
Developmental Regulation ◽  
Consensus Sequence ◽  
Specific Protein ◽  
Low Density ◽  
Nuclear Factor ◽  
Stage Of Development ◽  
Nuclear Extracts ◽  
Enhancer Binding Protein ◽  
Nuclear Factor 1

Expression of the avian very-low-density apolipoprotein II (apoVLDLII) gene is completely dependent on estrogen and restricted to the liver. We have identified binding sites for nonhistone nuclear proteins located between -1.96 and -2.61 kilobases. One of these sites, located at -2.6 kilobases (designated site 1), was found to span an MspI site that becomes demethylated between days 7 and 9 of embryogenesis, the stage of development at which competence to express the apoVLDLII gene begins to be acquired. Levels of the factor(s) involved were high at day 7 of embryogenesis, decreased two- to threefold by days 9 to 11, and continued to decline more slowly until hatching. Furthermore, the mobility of the complex formed underwent a well-defined shift between days 11 to 13 embryogenesis. Methylation interference studies showed that modification of the outer guanosines of the MspI site resulted in marked inhibition of the formation of the protein-DNA complex. Competition studies, fractionation of nuclear extracts, and tissue distribution indicated that the factor was not the avian homolog of hepatocyte nuclear factor 1, nuclear factor 1, or CCAAT/enhancer-binding protein (C/EBP). However, site 1 could complete for binding to an oligonucleotide, previously shown to be recognized by C/EBP, in a nonreciprocal fashion. These studies demonstrate that the sequence recognized by the protein includes a C/EBP consensus sequence but that elements in addition to the core enhancer motif are essential for binding.

Zinc finger protein ZFP36L1 inhibits flavivirus infection by both 5′-3′ XRN1 and 3′-5′ RNA-exosome RNA decay pathways.

2021 ◽  
Author(s):  
Han Chiu ◽  
Hsin-Ping Chiu ◽  
Han-Pang Yu ◽  
Li-Hsiung Lin ◽  
Zih-Ping Chen ◽  
...  
Keyword(s):  
Antiviral Activity ◽  
Dengue Virus ◽  
Zinc Finger ◽  
Rna Binding ◽  
Zinc Finger Protein ◽  
Viral Rna ◽  
Rna Decay ◽  
Finger Protein ◽  
Zinc Finger Motifs ◽  
Rna Exosome

Zinc-finger protein 36, CCCH type-like 1 (ZFP36L1), containing tandem CCCH-type zinc-finger motifs with an RNA-binding property, plays an important role in cellular RNA metabolism mainly via RNA decay pathways. Recently, we demonstrated that human ZFP36L1 has potent antiviral activity against influenza A virus infection. However, its role in the host defense response against flaviviruses has not been addressed. Here, we demonstrate that ZFP36L1 functions as a host innate defender against flaviviruses, including Japanese encephalitis virus (JEV) and dengue virus (DENV). Overexpression of ZFP36L1 reduced JEV and DENV infection, and ZFP36L1 knockdown enhanced viral replication. ZFP36L1 destabilized the JEV genome by targeting and degrading viral RNA mediated by both 5′-3′ XRN1 and 3′-5′ RNA-exosome RNA decay pathways. Mutation in both zinc-finger motifs of ZFP36L1 disrupted RNA-binding and antiviral activity. Furthermore, the viral RNA sequences specifically recognized by ZFP36L1 were mapped to the 3'-untranslated region of the JEV genome with the AU-rich element (AUUUA) motif. We extend the function of ZFP36L1 to host antiviral defense by directly binding and destabilizing the viral genome via recruiting cellular mRNA decay machineries. Importance Cellular RNA-binding proteins are among the first lines of defense against various viruses, particularly RNA viruses. ZFP36L1 belongs to the CCCH-type zinc-finger protein family and has RNA-binding activity; it has been reported to directly bind to the AU-rich elements (AREs) of a subset of cellular mRNAs and then lead to mRNA decay by recruiting mRNA degrading enzymes. However, the antiviral potential of ZFP36L1 against flaviviruses has not yet been fully demonstrated. Here, we reveal the antiviral potential of human ZFP36L1 against Japanese encephalitis virus (JEV) and dengue virus (DENV). ZFP36L1 specifically targeted the ARE motif within viral RNA and triggered the degradation of viral RNA transcripts via cellular degrading enzymes, 5′-3′ XRN1 and 3′-5′ RNA exosome. These findings provide mechanistic insights into how human ZFP36L1 serves as a host antiviral factor to restrict flavivirus replication.

SDC-3 coordinates the assembly of a dosage compensation complex on the nematode X chromosome

Development ◽  
1997 ◽  
Vol 124 (5) ◽  
pp. 1019-1031 ◽  
Author(s):  
T.L. Davis ◽  
B.J. Meyer
Keyword(s):  
Zinc Finger ◽  
X Chromosome ◽  
Dosage Compensation ◽  
Protein Complex ◽  
Terminal Region ◽  
X Chromosomes ◽  
C Elegans ◽  
Amino Terminal ◽  
Zinc Finger Motifs ◽  
Specific Association

X chromosome expression in C. elegans is controlled by a chromosome-wide regulatory process called dosage compensation that specifically reduces by half the level of transcripts made from each hermaphrodite X chromosome. This process equalizes X expression between the sexes (XX hermaphrodites and XO males), despite their two-fold difference in X chromosome dose, and thereby prevents sex-specific lethality. Dosage compensation is achieved by a protein complex that associates with X in a sex-specific fashion to modulate gene expression. SDC-3, a protein that coordinately controls both sex determination and dosage compensation, activates dosage compensation by directing the dosage compensation protein complex to the hermaphrodite X chromosomes. We show that SDC-3 coordinates this assembly through its own sex-specific association with X. SDC-3 in turn requires other members of the dosage compensation gene hierarchy for its stability and its X localization. In addition, SDC-3 requires its own zinc finger motifs and an amino-terminal region for its X association. Our experiments suggest the possible involvement of zinc finger motifs in X chromosome recognition and the amino-terminal region in interactions with other dosage compensation proteins.

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