scholarly journals Functional analyses of the CIF1-CIF2 complex in Trypanosoma brucei identify the structural motifs required for complex formation and cytokinesis

2017 ◽  
Author(s):  
Huiqing Hu ◽  
Paul Majneri ◽  
Dielan Li ◽  
Yasuhiro Kurasawa ◽  
Tai An ◽  
...  
Keyword(s):  
Zinc Finger ◽  
Coiled Coil ◽  
Longitudinal Axis ◽  
Zinc Finger Motif ◽  
Structural Motifs ◽  
Zinc Finger Motifs ◽  
Ef Hand ◽  
Functional Analyses ◽  
Attachment Zone ◽  
Structural Insights

ABSTRACTCytokinesis in trypanosome occurs uni-directionally along the longitudinal axis from the cell anterior towards the cell posterior and requires a trypanosome-specific CIF1-CIF2 protein complex. However, little is known about the contribution of the structural motifs in CIF1 and CIF2 to complex assembly and cytokinesis. Here, we demonstrated that the two zinc-finger motifs but not the coiled-coil motif in CIF1 are required for interaction with the EF-hand motifs in CIF2. We further showed that localization of CIF1 depends on the coiled-coil motif and the first zinc-finger motif and that localization of CIF2 depends on the EF-hand motifs. Deletion of the coiled-coil motif and mutation of either zinc-finger motifs in CIF1 disrupted cytokinesis. Further, mutation of either zinc-finger motif in CIF1 mis-localized CIF2 to the cytosol and destabilized CIF2, whereas deletion of the coiled-coil motif in CIF1 spread CIF2 over to the new flagellum attachment zone and stabilized CIF2. Together, these results uncovered the requirement of the coiled-coil motif and zinc-finger motifs for CIF1 function in cytokinesis and for CIF2 localization and stability, providing structural insights into the functional interplay between the two cytokinesis regulators.

scholarly journals Seesaw conformations of Npl4 in the human p97 complex and the inhibitory mechanism of a disulfiram derivative

2021 ◽  
Vol 12 (1) ◽  
Author(s):  
Man Pan ◽  
Qingyun Zheng ◽  
Yuanyuan Yu ◽  
Huasong Ai ◽  
Yuan Xie ◽  
...  
Keyword(s):  
Zinc Finger ◽  
Atp Hydrolysis ◽  
Cellular Protein ◽  
Cancer Drug ◽  
Copper Transporter ◽  
Cryo Electron Microscopy ◽  
Zinc Finger Motifs ◽  
Structural Insights ◽  
Target Cancer

Abstractp97, also known as valosin-containing protein (VCP) or Cdc48, plays a central role in cellular protein homeostasis. Human p97 mutations are associated with several neurodegenerative diseases. Targeting p97 and its cofactors is a strategy for cancer drug development. Despite significant structural insights into the fungal homolog Cdc48, little is known about how human p97 interacts with its cofactors. Recently, the anti-alcohol abuse drug disulfiram was found to target cancer through Npl4, a cofactor of p97, but the molecular mechanism remains elusive. Here, using single-particle cryo-electron microscopy (cryo-EM), we uncovered three Npl4 conformational states in complex with human p97 before ATP hydrolysis. The motion of Npl4 results from its zinc finger motifs interacting with the N domain of p97, which is essential for the unfolding activity of p97. In vitro and cell-based assays showed that the disulfiram derivative bis-(diethyldithiocarbamate)-copper (CuET) can bypass the copper transporter system and inhibit the function of p97 in the cytoplasm by releasing cupric ions under oxidative conditions, which disrupt the zinc finger motifs of Npl4, locking the essential conformational switch of the complex.

scholarly journals Gamma Radiation-Induced Damage in the Zinc Finger of the Transcription Factor IIIA

2016 ◽  
Vol 2016 ◽  
pp. 1-7 ◽  
Author(s):  
XiaoHong Zhang ◽  
YuJi Miao ◽  
XiaoDan Hu ◽  
Rui Min ◽  
PeiDang Liu ◽  
...  
Keyword(s):  
Transcription Factor ◽  
Ionizing Radiation ◽  
Gamma Radiation ◽  
Zinc Finger ◽  
Cysteine Residues ◽  
Zinc Finger Motif ◽  
Thiol Groups ◽  
Transcription Factor Iiia ◽  
Zinc Finger Motifs ◽  
Radiation Induced

A zinc finger motif is an element of proteins that can specifically recognize and bind to DNA. Because they contain multiple cysteine residues, zinc finger motifs possess redox properties. Ionizing radiation generates a variety of free radicals in organisms. Zinc finger motifs, therefore, may be a target of ionizing radiation. The effect of gamma radiation on the zinc finger motifs in transcription factor IIIA (TFIIIA), a zinc finger protein, was investigated. TFIIIA was exposed to different gamma doses from 60Co sources. The dose rates were 0.20 Gy/min and 800 Gy/h, respectively. The binding capacity of zinc finger motifs in TFIIIA was determined using an electrophoretic mobility shift assay. We found that 1000 Gy of gamma radiation impaired the function of the zinc finger motifs in TFIIIA. The sites of radiation-induced damage in the zinc finger were the thiol groups of cysteine residues and zinc (II) ions. The thiol groups were oxidized to form disulfide bonds and the zinc (II) ions were indicated to be reduced to zinc atoms. These results indicate that the zinc finger motif is a target domain for gamma radiation, which may decrease 5S rRNA expression via impairment of the zinc finger motifs in TFIIIA.

scholarly journals LIS1, CLIP-170's Key to the Dynein/Dynactin Pathway

2002 ◽  
Vol 22 (9) ◽  
pp. 3089-3102 ◽  
Author(s):  
Frédéric M. Coquelle ◽  
Michal Caspi ◽  
Fabrice P. Cordelières ◽  
Jim P. Dompierre ◽  
Denis L. Dujardin ◽  
...  
Keyword(s):  
Brain Development ◽  
Zinc Finger ◽  
Protein Interactions ◽  
Mammalian Cells ◽  
Direct Interaction ◽  
Cytoplasmic Dynein ◽  
Zinc Finger Motif ◽  
Protein Protein Interactions ◽  
Terminal Domain ◽  
Zinc Finger Motifs

ABSTRACT CLIP-170 is a plus-end tracking protein which may act as an anticatastrophe factor. It has been proposed to mediate the association of dynein/dynactin to microtubule (MT) plus ends, and it also binds to kinetochores in a dynein/dynactin-dependent fashion, both via its C-terminal domain. This domain contains two zinc finger motifs (proximal and distal), which are hypothesized to mediate protein-protein interactions. LIS1, a protein implicated in brain development, acts in several processes mediated by the dynein/dynactin pathway by interacting with dynein and other proteins. Here we demonstrate colocalization and direct interaction between CLIP-170 and LIS1. In mammalian cells, LIS1 recruitment to kinetochores is dynein/dynactin dependent, and recruitment there of CLIP-170 is dependent on its site of binding to LIS1, located in the distal zinc finger motif. Overexpression of CLIP-170 results in a zinc finger-dependent localization of a phospho-LIS1 isoform and dynactin to MT bundles, raising the possibility that CLIP-170 and LIS1 regulate dynein/dynactin binding to MTs. This work suggests that LIS1 is a regulated adapter between CLIP-170 and cytoplasmic dynein at sites involved in cargo-MT loading, and/or in the control of MT dynamics.

Integrity of zinc finger motifs in PML protein is necessary for inducing its degradation by antimony

Metallomics ◽  
2019 ◽  
Vol 11 (8) ◽  
pp. 1419-1429 ◽  
Author(s):  
Chang Yang ◽  
Rui Hao ◽  
Yong Fei Lan ◽  
Ye Jia Chen ◽  
Chao Wang ◽  
...  
Keyword(s):  
Zinc Finger ◽  
Zinc Ions ◽  
Zinc Finger Motif ◽  
Zinc Finger Motifs ◽  
Fundamental Requirement

The presence of zinc ions in a zinc finger motif of a PML protein is a fundamental requirement for the protein's degradation by antimony.

scholarly journals Seesaw Conformations of Npl4 in the Human p97 Complex and the Inhibitory Mechanism of a Disulfiram Derivative

2020 ◽  
Author(s):  
Man Pan ◽  
Qingyun Zheng ◽  
Yuanyuan Yu ◽  
Huasong Ai ◽  
Yuan Xie ◽  
...  
Keyword(s):  
Zinc Finger ◽  
Atp Hydrolysis ◽  
Cellular Protein ◽  
Cancer Drug ◽  
Protein Homeostasis ◽  
Cryo Electron Microscopy ◽  
Zinc Finger Motifs ◽  
Structural Insights ◽  
Target Cancer

ABSTRACTp97, also known as valosin-containing protein (VCP) or Cdc48, plays a central role in cellular protein homeostasis1. Human p97 mutations are associated with several neurodegenerative diseases2,3. Targeting p97 and its cofactors is a strategy for cancer drug development4. Despite significant structural insights into the fungal homolog Cdc485–7, little is known about how human p97 interacts with its cofactors. Recently, the anti-alcohol abuse drug disulfiram was found to target cancer through Npl4, a cofactor of p978, but the molecular mechanism remains elusive. Here, using single-particle cryo-electron microscopy (cryo-EM), we uncovered three Npl4 conformational states in complex with human p97 before ATP hydrolysis. The motion of Npl4 results from its zinc finger motifs interacting with the N domain of p97, which is essential for the unfolding activity of p97. In vitro and cell-based assays showed that under oxidative conditions, the disulfiram derivative bis-(diethyldithiocarbamate)-copper (CuET) inhibits p97 function by releasing cupric ions, which disrupt the zinc finger motifs of Npl4, locking the essential conformational switch of the complex.

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.

scholarly journals Interleukin-11 binds specific EF-hand proteins via their conserved structural motifs

2016 ◽  
Vol 35 (1) ◽  
pp. 78-91 ◽  
Author(s):  
Alexei S. Kazakov ◽  
Andrei S. Sokolov ◽  
Alisa A. Vologzhannikova ◽  
Maria E. Permyakova ◽  
Polina A. Khorn ◽  
...  
Keyword(s):  
Structural Motifs ◽  
Ef Hand ◽  
Interleukin 11

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 The LIM/double zinc-finger motif functions as a protein dimerization domain.

1994 ◽  
Vol 91 (22) ◽  
pp. 10655-10659 ◽  
Author(s):  
R. Feuerstein ◽  
X. Wang ◽  
D. Song ◽  
N. E. Cooke ◽  
S. A. Liebhaber
Keyword(s):  
Zinc Finger ◽  
Zinc Finger Motif ◽  
Dimerization Domain ◽  
Protein Dimerization
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