scholarly journals The Roles of Arabidopsis C1-2i Subclass of C2H2-type Zinc-Finger Transcription Factors

Genes ◽  
2019 ◽  
Vol 10 (9) ◽  
pp. 653 ◽  
Author(s):  
Minmin Xie ◽  
Jinhao Sun ◽  
Daping Gong ◽  
Yingzhen Kong

The Cys2His2 (C2H2)-type zinc-finger protein (ZFP) family, which includes 176 members in Arabidopsis thaliana, is one of the largest families of putative transcription factors in plants. Of the Arabidopsis ZFP members, only 33 members are conserved in other eukaryotes, with 143 considered to be plant specific. C2H2-type ZFPs have been extensively studied and have been shown to play important roles in plant development and environmental stress responses by transcriptional regulation. The ethylene-responsive element binding-factor-associated amphiphilic repression (EAR) domain (GCC box) has been found to have a critical role in the tolerance response to abiotic stress. Many of the plant ZFPs containing the EAR domain, such as AZF1/2/3, ZAT7, ZAT10, and ZAT12, have been shown to function as transcriptional repressors. In this review, we mainly focus on the C1-2i subclass of C2H2 ZFPs and summarize the latest research into their roles in various stress responses. The role of C2H2-type ZFPs in response to the abiotic and biotic stress signaling network is not well explained, and amongst them, C1-2i is one of the better-characterized classifications in response to environmental stresses. These studies of the C1-2i subclass ought to furnish the basis for future studies to discover the pathways and receptors concerned in stress defense. Research has implied possible protein-protein interactions between members of C1-2i under various stresses, for which we have proposed a hypothetical model.

2005 ◽  
Vol 386 (2) ◽  
pp. 95-99 ◽  
Author(s):  
Alexander E.F. Smith ◽  
Farzin Farzaneh ◽  
Kevin G. Ford

AbstractIn order to demonstrate that an existing zinc-finger protein can be simply modified to enhance DNA binding and sequence discrimination in both episomal and chromatin contexts using existing zinc-finger DNA recognition code data, and without recourse to phage display and selection strategies, we have examined the consequences of a single zinc-finger extension to a synthetic three-zinc-finger VP16 fusion protein, on transcriptional activation from model target promoters harbouring the zinc-finger binding sequences. We report a nearly 10-fold enhanced transcriptional activation by the four-zinc-finger VP16 fusion protein relative to the progenitor three-finger VP16 protein in transient assays and a greater than five-fold enhancement in stable reporter-gene expression assays. A marked decrease in transcriptional activation was evident for the four-zinc-finger derivative from mutated regulatory regions compared to the progenitor protein, as a result of recognition site-size extension. This discriminatory effect was shown to be protein concentration-dependent. These observations suggest that four-zinc-finger proteins are stable functional motifs that can be a significant improvement over the progenitor three-zinc-finger protein, both in terms of specificity and the ability to target transcriptional function to promoters, and that single zinc-finger extension can therefore have a significant impact on DNA zinc-finger protein interactions. This is a simple route for modifying or enhancing the binding properties of existing synthetic zinc-finger-based transcription factors and may be particularly suited for the modification of endogenous zinc-finger transcription factors for promoter biasing applications.


1995 ◽  
Vol 15 (5) ◽  
pp. 2448-2456 ◽  
Author(s):  
M Crossley ◽  
M Merika ◽  
S H Orkin

GATA-1, the founding member of a distinctive family of transcription factors, is expressed predominantly in erythroid cells and participates in the expression of numerous erythroid cell-expressed genes. GATA-binding sites are found in the promoters and enhancers of globin and nonglobin erythroid genes as well as in the alpha- and beta-globin locus control regions. To elucidate how GATA-1 may function in a variety of regulatory contexts, we have examined its protein-protein interactions. Here we show that GATA-1 self-associates in solution and in whole-cell extracts and that the zinc finger region of the molecule is sufficient to mediate this interaction. This physical interaction can influence transcription, as GATA-1 self-association is able to recruit a transcriptionally active but DNA-binding-defective derivative of GATA-1 to promoter-bound GATA-1 and result in superactivation. Through in vitro studies with bacterially expressed glutathione S-transferase fusion proteins, we have localized the minimal domain required for GATA-1 self-association to 40 amino acid residues within the C-terminal zinc finger region. Finally, we have detected physical interaction of GATA-1 with other GATA family members (GATA-2 and GATA-3) also mediated through the zinc finger domain. These findings have broad implications for the involvement of GATA factors in transcriptional control. In particular, the interaction of GATA-1 with itself and with other transcription factors may facilitate its function at diverse promoters in erythroid cells and also serve to bring together, or stabilize, loops between distant regulatory elements, such as the globin locus control regions and downstream globin promoters. We suggest that the zinc finger region of GATA-1, and related proteins, is multifunctional and mediates not only DNA binding but also important protein-protein interactions.


Molecules ◽  
2021 ◽  
Vol 26 (20) ◽  
pp. 6296
Author(s):  
Elena Cesaro ◽  
Angelo Lupo ◽  
Roberta Rapuano ◽  
Arianna Pastore ◽  
Michela Grosso ◽  
...  

The transcription factor ZNF224 is a Kruppel-like zinc finger protein that consists of 707 amino acids and contains 19 tandemly repeated C2H2 zinc finger domains that mediate DNA binding and protein–protein interactions. ZNF224 was originally identified as a transcriptional repressor of genes involved in energy metabolism, and it was demonstrated that ZNF224-mediated transcriptional repression needs the interaction of its KRAB repressor domain with the co-repressor KAP1 and its zinc finger domains 1–3 with the arginine methyltransferase PRMT5. Furthermore, the protein ZNF255 was identified as an alternative isoform of ZNF224 that possesses different domain compositions mediating distinctive functional interactions. Subsequent studies showed that ZNF224 is a multifunctional protein able to exert different transcriptional activities depending on the cell context and the variety of its molecular partners. Indeed, it has been shown that ZNF224 can act as a repressor, an activator and a cofactor for other DNA-binding transcription factors in different human cancers. Here, we provide a brief overview of the current knowledge on the multifaceted interactions of ZNF224 and the resulting different roles of this protein in various cellular contexts.


2013 ◽  
Vol 73 (5) ◽  
pp. 761-775 ◽  
Author(s):  
Yusuke Nakai ◽  
Yoichi Nakahira ◽  
Hiroki Sumida ◽  
Kosuke Takebayashi ◽  
Yumiko Nagasawa ◽  
...  

2018 ◽  
Author(s):  
R. Murugan

ABSTRACTWe show that the looping mediated transcription activation by the combinatorial transcription factors (TFs) can be achieved via directional-dependent propulsion, tethered sliding and tethered binding-sliding-unbinding modes. In the propulsion mode, the first arrived TF at the cis-regulatory motifs (CRMs) further recruits other TFs via protein-protein interactions. Such TFs complex has two different types of DNA binding domains (DBDs) viz. DBD1 which forms tight site-specific complex with CRMs via hydrogen bonding network and the promoter specific DBD2s which form nonspecific interactions around CRMs. When the sum of these specific and cumulative nonspecific interactions is sufficient, then the flanking DNA of CRMs will be bent into a circle over the TFs complex. The number of TFs involved in the combinatorial regulation plays critical role here. When the site-specific interactions and the cumulative nonspecific interactions are strong enough to resist the dissociation, then the sliding of DBD2s well within the Onsager radius associated with the DBD2s-DNA interface towards the promoter is the only possible way to release the elastic stress of the bent DNA. The DBD2s form tight synaptosome complex upon finding the promoter via sliding. When the number of TFs is not enough to bend the DNA in to a circle, then tethered sliding or tethered binding-sliding-unbinding modes are the possibilities. In tethered sliding, the CRMs-TFs complex forms nonspecific contacts with DNA via dynamic loops and then slide along DNA towards promoter without dissociation. In tethered binding-sliding-unbinding, the CRMs-TFs performs several cycles of nonspecific binding-sliding-unbinding before finding the promoter. Elastic and entropic energy barriers associated with the looping of DNA shape up the distribution of distances between CRMs and promoters. The combinatorial regulation of TFs in eukaryotes has evolved to overcome the looping energy barrier.


2018 ◽  
Vol 19 (12) ◽  
pp. 3731 ◽  
Author(s):  
Kasavajhala Prasad ◽  
Denghui Xing ◽  
Anireddy Reddy

Soil salinity, a significant problem in agriculture, severely limits the productivity of crop plants. Plants respond to and cope with salt stress by reprogramming gene expression via multiple signaling pathways that converge on transcription factors. To develop strategies to generate salt-tolerant crops, it is necessary to identify transcription factors that modulate salt stress responses in plants. In this study, we investigated the role of VOZ (VASCULAR PLANT ONE-ZINC FINGER PROTEIN) transcription factors (VOZs) in salt stress response. Transcriptome analysis in WT (wild-type), voz1-1, voz2-1 double mutant and a VOZ2 complemented line revealed that many stress-responsive genes are regulated by VOZs. Enrichment analysis for gene ontology terms in misregulated genes in voz double mutant confirmed previously identified roles of VOZs and suggested a new role for them in salt stress. To confirm VOZs role in salt stress, we analyzed seed germination and seedling growth of WT, voz1, voz2-1, voz2-2 single mutants, voz1-1 voz2-1 double mutant and a complemented line under different concentrations of NaCl. Only the double mutant exhibited hypersensitivity to salt stress as compared to WT, single mutants, and a complemented line. Expression analysis showed that hypersensitivity of the double mutant was accompanied by reduced expression of salt-inducible genes. These results suggest that VOZ transcription factors act as positive regulators of several salt-responsive genes and that the two VOZs are functionally redundant in salt stress.


2019 ◽  
Vol 19 (6) ◽  
pp. 430-448 ◽  
Author(s):  
Khalid Bashir Dar ◽  
Aashiq Hussain Bhat ◽  
Shajrul Amin ◽  
Syed Anjum ◽  
Bilal Ahmad Reshi ◽  
...  

Protein-Protein Interactions (PPIs) drive major signalling cascades and play critical role in cell proliferation, apoptosis, angiogenesis and trafficking. Deregulated PPIs are implicated in multiple malignancies and represent the critical targets for treating cancer. Herein, we discuss the key protein-protein interacting domains implicated in cancer notably PDZ, SH2, SH3, LIM, PTB, SAM and PH. These domains are present in numerous enzymes/kinases, growth factors, transcription factors, adaptor proteins, receptors and scaffolding proteins and thus represent essential sites for targeting cancer. This review explores the candidature of various proteins involved in cellular trafficking (small GTPases, molecular motors, matrix-degrading enzymes, integrin), transcription (p53, cMyc), signalling (membrane receptor proteins), angiogenesis (VEGFs) and apoptosis (BCL-2family), which could possibly serve as targets for developing effective anti-cancer regimen. Interactions between Ras/Raf; X-linked inhibitor of apoptosis protein (XIAP)/second mitochondria-derived activator of caspases (Smac/DIABLO); Frizzled (FRZ)/Dishevelled (DVL) protein; beta-catenin/T Cell Factor (TCF) have also been studied as prospective anticancer targets. Efficacy of diverse molecules/ drugs targeting such PPIs although evaluated in various animal models/cell lines, there is an essential need for human-based clinical trials. Therapeutic strategies like the use of biologicals, high throughput screening (HTS) and fragment-based technology could play an imperative role in designing cancer therapeutics. Moreover, bioinformatic/computational strategies based on genome sequence, protein sequence/structure and domain data could serve as competent tools for predicting PPIs. Exploring hot spots in proteomic networks represents another approach for developing targetspecific therapeutics. Overall, this review lays emphasis on a productive amalgamation of proteomics, genomics, biochemistry, and molecular dynamics for successful treatment of cancer.


Brain ◽  
2019 ◽  
Vol 142 (8) ◽  
pp. 2380-2401 ◽  
Author(s):  
Saurav Brahmachari ◽  
Saebom Lee ◽  
Sangjune Kim ◽  
Changqing Yuan ◽  
Senthilkumar S Karuppagounder ◽  
...  

Abstract α-Synuclein misfolding and aggregation plays a major role in the pathogenesis of Parkinson’s disease. Although loss of function mutations in the ubiquitin ligase, parkin, cause autosomal recessive Parkinson’s disease, there is evidence that parkin is inactivated in sporadic Parkinson’s disease. Whether parkin inactivation is a driver of neurodegeneration in sporadic Parkinson’s disease or a mere spectator is unknown. Here we show that parkin in inactivated through c-Abelson kinase phosphorylation of parkin in three α-synuclein-induced models of neurodegeneration. This results in the accumulation of parkin interacting substrate protein (zinc finger protein 746) and aminoacyl tRNA synthetase complex interacting multifunctional protein 2 with increased parkin interacting substrate protein levels playing a critical role in α-synuclein-induced neurodegeneration, since knockout of parkin interacting substrate protein attenuates the degenerative process. Thus, accumulation of parkin interacting substrate protein links parkin inactivation and α-synuclein in a common pathogenic neurodegenerative pathway relevant to both sporadic and familial forms Parkinson’s disease. Thus, suppression of parkin interacting substrate protein could be a potential therapeutic strategy to halt the progression of Parkinson’s disease and related α-synucleinopathies.


2012 ◽  
Vol 23 (19) ◽  
pp. 3911-3922 ◽  
Author(s):  
Yongqiang Wang ◽  
Xinlei Zhang ◽  
Hong Zhang ◽  
Yi Lu ◽  
Haolong Huang ◽  
...  

The highly abundant α-helical coiled-coil motif not only mediates crucial protein–protein interactions in the cell but is also an attractive scaffold in synthetic biology and material science and a potential target for disease intervention. Therefore a systematic understanding of the coiled-coil interactions (CCIs) at the organismal level would help unravel the full spectrum of the biological function of this interaction motif and facilitate its application in therapeutics. We report the first identified genome-wide CCI network in Saccharomyces cerevisiae, which consists of 3495 pair-wise interactions among 598 predicted coiled-coil regions. Computational analysis revealed that the CCI network is specifically and functionally organized and extensively involved in the organization of cell machinery. We further show that CCIs play a critical role in the assembly of the kinetochore, and disruption of the CCI network leads to defects in kinetochore assembly and cell division. The CCI network identified in this study is a valuable resource for systematic characterization of coiled coils in the shaping and regulation of a host of cellular machineries and provides a basis for the utilization of coiled coils as domain-based probes for network perturbation and pharmacological applications.


2002 ◽  
Vol 2 ◽  
pp. 1569-1578 ◽  
Author(s):  
David J. Granville ◽  
Roberta A. Gottlieb

The past 5 years has seen an intense surge in research devoted toward understanding the critical role of mitochondria in the regulation of cell death. Apoptosis can be initiated by a wide array of stimuli, inducing multiple signaling pathways that, for the most part, converge at the mitochondrion. Although classically considered the powerhouses of the cell, it is now understood that mitochondria are also “gatekeepers” that ultimately determine the fate of the cell. The mitochondrial decision as to whether a cell lives or dies is complex, involving protein-protein interactions, ionic changes, reactive oxygen species, and other mechanisms that require further elucidation. Once the death process is initiated, mitochondria undergo conformational changes, resulting in the release of cytochrome c (cyt c), caspases, endonucleases, and other factors leading to the onset and execution of apoptosis. The present review attempts to outline the complex milieu of events regulating the mitochondrial commitment to and processes involved in the implementation of the executioner phase of apoptotic cell death.


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