scholarly journals The gynoecious CmWIP1 transcription factor interacts with CmbZIP48 to inhibit carpel development

2019 ◽  
Vol 9 (1) ◽  
Author(s):  
John S. Y. Eleblu ◽  
Aimen Haraghi ◽  
Brahim Mania ◽  
Celine Camps ◽  
Dali Rashid ◽  
...  

Abstract In angiosperms, sex determination leads to development of unisexual flowers. In Cucumis melo, development of unisexual male flowers results from the expression of the sex determination gene, CmWIP1, in carpel primordia. To bring new insight on the molecular mechanisms through which CmWIP1 leads to carpel abortion in male flowers, we used the yeast two-hybrid approach to look for CmWIP1-interacting proteins. We found that CmWIP1 physically interacts with an S2 bZIP transcription factor, CmbZIP48. We further determined the region mediating the interaction and showed that it involves the N-terminal part of CmWIP1. Using laser capture microdissection coupled with quantitative real-time gene expression analysis, we demonstrated that CmWIP1 and CmbZIP48 share a similar spatiotemporal expression pattern, providing the plant organ context for the CmWIP1-CmbZIP48 protein interaction. Using sex transition mutants, we demonstrated that the expression of the male promoting gene CmWIP1 correlates with the expression of CmbZIP48. Altogether, our data support a model in which the coexpression and the physical interaction of CmWIP1 and CmbZIP48 trigger carpel primordia abortion, leading to the development of unisexual male flowers.

2020 ◽  
Vol 32 (1) ◽  
pp. 273-284 ◽  
Author(s):  
Qiaoying Chang ◽  
Xin Lu ◽  
Zhi Liu ◽  
Zhimin Zheng ◽  
Song Yu

AbstractThe basic leucine zipper (bZIP) transcription factor family is one of the largest and most diverse families in plants, regulating plant growth and development and playing an essential role in response to abiotic and biotic stresses. However, little is known about the biological functions of bZIP proteins in yellowhorn (Xanthoceras sorbifolium). Recently, 64 XsbZIP genes were identified in the yellowhorn genome and found to be disproportionately distributed in linkage groups. The XsbZIP proteins clustered into 11 groups based on their phylogenetic relationships with AtbZIP, ZmbZIP and GmbZIP proteins. Five intron patterns in the basic and hinge regions and additional conserved motifs were defined, both supporting the group classification and possibly contributing to their functional diversity. Compared to tandem duplication, the segment duplication greatly contributed to the expansion of yellowhorn bZIP genes. In addition, most XsbZIP genes harbor several stress responsive cis-elements in their promoter regions. Moreover, the RNA-seq and qRT-PCR data indicated XsbZIP genes were extensively involved in response to various stresses, including salt (NaCl), cold and abscisic acid, with possibly different molecular mechanisms. These results provide a new understanding of the biological functions of bZIP transcription factors in yellowhorn.


1997 ◽  
Vol 17 (2) ◽  
pp. 584-593 ◽  
Author(s):  
J L Lenormand ◽  
B Benayoun ◽  
M Guillier ◽  
M Vandromme ◽  
M P Leibovitch ◽  
...  

The activities of myogenic basic helix-loop-helix (bHLH) factors are regulated by a number of different positive and negative signals. Extensive information has been published about the molecular mechanisms that interfere with the process of myogenic differentiation, but little is known about the positive signals. We previously showed that overexpression of rat Mos in C2C12 myoblasts increased the expression of myogenic markers whereas repression of Mos products by antisense RNAs inhibited myogenic differentiation. In the present work, our results show that the rat mos proto-oncogene activates transcriptional activity of MyoD protein. In transient transfection assays, Mos promotes transcriptional transactivation by MyoD of the muscle creatine kinase enhancer and/or a reporter gene linked to MyoD-DNA binding sites. Physical interaction between Mos and MyoD, but not with E12, is demonstrated in vivo by using the two-hybrid approach with C3H10T1/2 cells and in vitro by using the glutathione S-transferase (GST) pull-down assays. Unphosphorylated MyoD from myogenic cell lysates and/or bacterially expressed MyoD physically interacts with Mos. This interaction occurs via the helix 2 region of MyoD and a highly conserved region in Mos proteins with 40% similarity to the helix 2 domain of the E-protein class of bHLH factors. Phosphorylation of MyoD by activated GST-Mos protein inhibits the DNA-binding activity of MyoD homodimers and promotes MyoD-E12 heterodimer formation. These data support a novel function for Mos as a mediator (coregulator) of muscle-specific gene(s) expression.


PLoS Genetics ◽  
2017 ◽  
Vol 13 (11) ◽  
pp. e1006953 ◽  
Author(s):  
Nur Syafiqah Mohamad Ishak ◽  
Quang Dang Nong ◽  
Tomoaki Matsuura ◽  
Yasuhiko Kato ◽  
Hajime Watanabe

2021 ◽  
Vol 8 (1) ◽  
Author(s):  
Zeyu Cai ◽  
Congcong Yang ◽  
Jun Liao ◽  
Haifeng Song ◽  
Sheng Zhang

AbstractDioecious species evolved from species with monomorphic sex systems in order to achieve overall fitness gains by separating male and female functions. As reproductive organs, unisexual flowers have different reproductive roles and exhibit conspicuous sexual dimorphism. To date, little is known about the temporal variations in and molecular mechanisms underlying the morphology and reproductive costs of dioecious flowers. We investigated male and female flowers of Salix paraplesia in three flowering stages before pollination (the early, blooming and late stages) via transcriptional sequencing as well as metabolite content and phenotypic analysis. We found that a large number of sex-biased genes, rather than sex-limited genes, were responsible for sexual dimorphism in S. paraplesia flowers and that the variation in gene expression in male flowers intensified this situation throughout flower development. The temporal dynamics of sex-biased genes derived from changes in reproductive function during the different flowering stages. Sexually differentiated metabolites related to respiration and flavonoid biosynthesis exhibited the same bias directions as the sex-biased genes. These sex-biased genes were involved mainly in signal transduction, photosynthesis, respiration, cell proliferation, phytochrome biosynthesis, and phenol metabolism; therefore, they resulted in more biomass accumulation and higher energy consumption in male catkins. Our results indicated that sex-biased gene expression in S. paraplesia flowers is associated with different reproductive investments in unisexual flowers; male flowers require a greater reproductive investment to meet their higher biomass accumulation and energy consumption needs.


Horticulturae ◽  
2021 ◽  
Vol 8 (1) ◽  
pp. 38
Author(s):  
Patricio Zapata ◽  
Makarena González ◽  
Igor Pacheco ◽  
Claudia Jorquera ◽  
Claudia Silva-Andrade ◽  
...  

Kiwifruit (Actinidia deliciosa [A. Chev.], C.V. Liang & A. R. Ferguson, 1984) is a perennial plant, with morphologically hermaphroditic and functionally dioecious flowers. Fruits of this species are berries of great commercial and nutritional importance. Nevertheless, few studies have analyzed the molecular mechanisms involved in sexual differentiation in this species. To determine these mechanisms, we performed RNA-seq in floral tissue at stage 60 on the BBCH scale in cultivar ‘Hayward’ (H, female) and a seedling from ‘Green Light’ × ‘Tomuri’ (G × T, male). From these analyses, we obtained expression profiles of 24,888 (H) and 27,027 (G × T) genes, of which 6413 showed differential transcript abundance. Genetic ontology (GO) and KEGG analysis revealed activation of pathways associated with the translation of hormonal signals, plant-pathogen interaction, metabolism of hormones, sugars, and nucleotides. The analysis of the protein-protein interaction network showed that the genes ERL1, AG, AGL8, LFY, WUS, AP2, WRKY, and CO, are crucial elements in the regulation of the hormonal response for the formation and development of anatomical reproductive structures and gametophytes. On the other hand, genes encoding four Putative S-adenosyl-L-methionine-dependent methyltransferases (Achn201401, Achn281971, Achn047771 and Achn231981) were identified, which were up-regulated mainly in the male flowers. Moreover, the expression profiles of 15 selected genes through RT-qPCR were consistent with the results of RNA-seq. Finally, this work provides gene expression-based interactions between transcription factors and effector genes from hormonal signaling pathways, development of floral organs, biological and metabolic processes or even epigenetic mechanisms which could be involved in the kiwi sex-determination. Thus, in order to decode the nature of these interactions, it could be helpful to propose new models of flower development and sex determination in the Actinidia genus.


Blood ◽  
2005 ◽  
Vol 106 (11) ◽  
pp. 828-828 ◽  
Author(s):  
Andrew J. Woo ◽  
Tyler B. Moran ◽  
Seong-Kyu Choe ◽  
Yocheved L. Schindler ◽  
Matthew R. Sullivan ◽  
...  

Abstract The zinc finger transcription factor GATA-1 plays an essential role in megakaryocytic and erythroid terminal maturation. Yet the molecular mechanisms that control GATA-1 function are incompletely understood. Many transcription factors, in addition to binding DNA, make important protein-protein interactions that modulate their activity. Here, we show that GATA-1 participates in stable multiprotein complexes ranging from ~100 kDa to greater than 600 kDa in murine L8057 megakaryoblastic cells. We generated stable L8057 cell lines expressing metabolically biotinylated and FLAG epitope tagged GATA-1, and performed tandem anti-FLAG immunoaffinity and streptavidin affinity purification of GATA-1 associated complexes. Mass spectrometry (LC/MS/MS) of co-purified proteins identified the known GATA-1 associated proteins Friend of GATA-1 (FOG-1), SCL, Ldb1, Runx-1/Cbf-β, SP1 and all components of the NuRD complex. In addition, we reproducibly co-purified zfp148 (also called ZBP-89/BERF-1/BFCOL-1, mtβ), a ubiquitously expressed Kruppel-type zinc finger transcription factor that binds GC-rich DNA elements. Zfp148 also co-purified with GATA-1 in erythroid (MEL) cells. Physical interaction between GATA-1 and zfp148 was confirmed by co-immunoprecipitation experiments using an anti-zfp148 antibody, and their interaction domains mapped to a C-terminal region of zfp148 and the zinc finger domain of GATA-1. Morpholino-mediated knock-down of zfp148 expression in zebrafish embryos ablates thrombocyte (equivalent to mammalian megakaryocyte/platelet) development, but does not significantly affect erythroid development (equivalent to mammalian primitive erythropoiesis at this stage of development). In vitro differentiation of murine ES cells containing homozygous disruption zfp148 by genetrap insertion (zfp148gt/gt) shows essentially normal primitive erythropoiesis, but markedly impaired megakaryocytic and definitive erythropoiesis. Preliminary chimeric studies in adult mice demonstrate a failure of zfp148gt/gt ES cells to contribute to mature erythrocytes. These findings suggest that zfp148 cooperates with GATA-1 to control differentiation of erythroid and megakaryocytic lineages. The differential requirement of zfp148 for definitive, but not primitive, erythropoiesis raises the possibility of a role in developmental hemoglobin switching.


Author(s):  
David P. Bazett-Jones ◽  
Mark L. Brown

A multisubunit RNA polymerase enzyme is ultimately responsible for transcription initiation and elongation of RNA, but recognition of the proper start site by the enzyme is regulated by general, temporal and gene-specific trans-factors interacting at promoter and enhancer DNA sequences. To understand the molecular mechanisms which precisely regulate the transcription initiation event, it is crucial to elucidate the structure of the transcription factor/DNA complexes involved. Electron spectroscopic imaging (ESI) provides the opportunity to visualize individual DNA molecules. Enhancement of DNA contrast with ESI is accomplished by imaging with electrons that have interacted with inner shell electrons of phosphorus in the DNA backbone. Phosphorus detection at this intermediately high level of resolution (≈lnm) permits selective imaging of the DNA, to determine whether the protein factors compact, bend or wrap the DNA. Simultaneously, mass analysis and phosphorus content can be measured quantitatively, using adjacent DNA or tobacco mosaic virus (TMV) as mass and phosphorus standards. These two parameters provide stoichiometric information relating the ratios of protein:DNA content.


2019 ◽  
Vol 132 (23) ◽  
Author(s):  
Wenhui Zhou ◽  
Kayla M. Gross ◽  
Charlotte Kuperwasser

ABSTRACT The transcription factor Snai2, encoded by the SNAI2 gene, is an evolutionarily conserved C2H2 zinc finger protein that orchestrates biological processes critical to tissue development and tumorigenesis. Initially characterized as a prototypical epithelial-to-mesenchymal transition (EMT) transcription factor, Snai2 has been shown more recently to participate in a wider variety of biological processes, including tumor metastasis, stem and/or progenitor cell biology, cellular differentiation, vascular remodeling and DNA damage repair. The main role of Snai2 in controlling such processes involves facilitating the epigenetic regulation of transcriptional programs, and, as such, its dysregulation manifests in developmental defects, disruption of tissue homeostasis, and other disease conditions. Here, we discuss our current understanding of the molecular mechanisms regulating Snai2 expression, abundance and activity. In addition, we outline how these mechanisms contribute to disease phenotypes or how they may impact rational therapeutic targeting of Snai2 dysregulation in human disease.


2021 ◽  
Vol 4 (1) ◽  
Author(s):  
Ba Van Vu ◽  
Quyet Nguyen ◽  
Yuki Kondo-Takeoka ◽  
Toshiki Murata ◽  
Naoki Kadotani ◽  
...  

AbstractTransposable elements are common targets for transcriptional and post-transcriptional gene silencing in eukaryotic genomes. However, the molecular mechanisms responsible for sensing such repeated sequences in the genome remain largely unknown. Here, we show that machinery of homologous recombination (HR) and RNA silencing play cooperative roles in copy number-dependent de novo DNA methylation of the retrotransposon MAGGY in the fungusPyricularia oryzae. Genetic and physical interaction studies revealed thatRecAdomain-containing proteins, includingP. oryzaehomologs ofRad51, Rad55, andRad57, together with an uncharacterized protein, Ddnm1, form complex(es) and mediate either the overall level or the copy number-dependence of de novo MAGGY DNA methylation, likely in conjunction with DNA repair. Interestingly,P. oryzaemutants of specific RNA silencing components (MoDCL1andMoAGO2)were impaired in copy number-dependence of MAGGY methylation. Co-immunoprecipitation of MoAGO2 and HR components suggested a physical interaction between the HR and RNA silencing machinery in the process.


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