scholarly journals A gene for genetic background inZea mays: fine-mappingenhancer of teosinte branched1.2(etb1.2) to a YABBY class transcription factor

2016 ◽  
Author(s):  
Chin Jian Yang ◽  
Lisa E. Kursel ◽  
Anthony J. Studer ◽  
Madelaine E. Bartlett ◽  
Clinton J. Whipple ◽  
...  

ABSTRACTThe effects of an allelic substitution at a gene often depend critically on genetic background, the genotype at other genes in the genome. During the domestication of maize from its wild ancestor (teosinte), an allelic substitution atteosinte branched(tb1) caused changes in both plant and ear architecture. The effects oftb1on phenotype were shown to depend on multiple background loci including one called enhancer oftb1.2 (etb1.2).We mappedetb1.2to a YABBY class transcription factor (ZmYAB2.1) and showed that the maize alleles ofZmYAB2.1are either expressed at a lower level than teosinte alleles or disrupted by insertions in the sequences.tb1andetb1.2interact epistatically to control the length of internodes within the maize ear which affects how densely the kernels are packed on the ear. The interaction effect is also observed at the level of gene expression withtb1acting as a repressor ofZmYAB2.1expression. Curiously,ZmYAB2.1was previously identified as a candidate gene for another domestication trait in maize, non-shattering ears. Consistent with this proposed role,ZmYAB2.1is expressed in a narrow band of cells in immature ears that appears to represent a vestigial abscission (shattering) zone. Expression in this band of cells may also underlie the effect on internode elongation. The identification ofZmYAB2.1as a background factor interacting withtb1is a first step toward a gene-level understanding of howtb1and the background within which it works evolved in concert during maize domestication.

2020 ◽  
Vol 117 (48) ◽  
pp. 30639-30648
Author(s):  
Dan Hu ◽  
Emily C. Tjon ◽  
Karin M. Andersson ◽  
Gabriela M. Molica ◽  
Minh C. Pham ◽  
...  

IL-17–producing Th17 cells are implicated in the pathogenesis of rheumatoid arthritis (RA) and TNF-α, a proinflammatory cytokine in the rheumatoid joint, facilitates Th17 differentiation. Anti-TNF therapy ameliorates disease in many patients with rheumatoid arthritis (RA). However, a significant proportion of patients do not respond to this therapy. The impact of anti-TNF therapy on Th17 responses in RA is not well understood. We conducted high-throughput gene expression analysis of Th17-enriched CCR6+CXCR3−CD45RA−CD4+T (CCR6+T) cells isolated from anti-TNF–treated RA patients classified as responders or nonresponders to therapy. CCR6+T cells from responders and nonresponders had distinct gene expression profiles. Proinflammatory signaling was elevated in the CCR6+T cells of nonresponders, and pathogenic Th17 signature genes were up-regulated in these cells. Gene set enrichment analysis on these signature genes identified transcription factor USF2 as their upstream regulator, which was also increased in nonresponders. Importantly, short hairpin RNA targetingUSF2in pathogenic Th17 cells led to reduced expression of proinflammatory cytokines IL-17A, IFN-γ, IL-22, and granulocyte-macrophage colony-stimulating factor (GM-CSF) as well as transcription factor T-bet. Together, our results revealed inadequate suppression of Th17 responses by anti-TNF in nonresponders, and direct targeting of the USF2-signaling pathway may be a potential therapeutic approach in the anti-TNF refractory RA.


2005 ◽  
Vol 83 (4) ◽  
pp. 535-547 ◽  
Author(s):  
Gareth N Corry ◽  
D Alan Underhill

To date, the majority of the research regarding eukaryotic transcription factors has focused on characterizing their function primarily through in vitro methods. These studies have revealed that transcription factors are essentially modular structures, containing separate regions that participate in such activities as DNA binding, protein–protein interaction, and transcriptional activation or repression. To fully comprehend the behavior of a given transcription factor, however, these domains must be analyzed in the context of the entire protein, and in certain cases the context of a multiprotein complex. Furthermore, it must be appreciated that transcription factors function in the nucleus, where they must contend with a variety of factors, including the nuclear architecture, chromatin domains, chromosome territories, and cell-cycle-associated processes. Recent examinations of transcription factors in the nucleus have clarified the behavior of these proteins in vivo and have increased our understanding of how gene expression is regulated in eukaryotes. Here, we review the current knowledge regarding sequence-specific transcription factor compartmentalization within the nucleus and discuss its impact on the regulation of such processes as activation or repression of gene expression and interaction with coregulatory factors.Key words: transcription, subnuclear localization, chromatin, gene expression, nuclear architecture.


Biomolecules ◽  
2021 ◽  
Vol 11 (7) ◽  
pp. 1021
Author(s):  
Carla Abrahamian ◽  
Christian Grimm

Microphthalmia-associated transcription factor (MITF) is the principal transcription factor regulating pivotal processes in melanoma cell development, growth, survival, proliferation, differentiation and invasion. In recent years, convincing evidence has been provided attesting key roles of endolysosomal cation channels, specifically TPCs and TRPMLs, in cancer, including breast cancer, glioblastoma, bladder cancer, hepatocellular carcinoma and melanoma. In this review, we provide a gene expression profile of these channels in different types of cancers and decipher their roles, in particular the roles of two-pore channel 2 (TPC2) and TRPML1 in melanocytes and melanoma. We specifically discuss the signaling cascades regulating MITF and the relationship between endolysosomal cation channels, MAPK, canonical Wnt/GSK3 pathways and MITF.


2021 ◽  
Vol 80 (Suppl 1) ◽  
pp. 23.2-24
Author(s):  
Y. P. Tsao ◽  
F. Y. Tseng ◽  
C. W. Chao ◽  
M. H. Chen ◽  
S. T. Chen

Background:Systemic lupus erythematous (SLE) is a systemic autoimmune disease with diverse etiological factors. It was recognized that interferon (IFN) signature involved in the progress of SLE. NLRP12 (NOD-like receptor family (NLR) pyrin domain containing 12) is a pyrin containing NLR protein that we had linked its new biological function to the cross-regulation of Toll like receptor (TLRs) and Rig-I like receptor (RIG-I) pathways. NLPR12 acts as an innate immune check-point in regulating type I IFNs expression during TLRs and RIG-I activation. The importance of NLRP12 in lupus disease activity remained to be elucidated.Objectives:To clarify the role of NLRP12 in regulating the interferon signature.Methods:Peripheral blood mononuclear cells (PBMCs) were collected from SLE patients and healthy donors for analysis of NLRP12 and IFN-α gene expression by RT-QPCR. PBMCs were applied for Chromatin immuneprecipitation (ChIP) assay and electrical mobility shift assay (EMSA) to determine the putative transcription factor that regulates NLRP12 expression. An involvement of epigenetic regulation of NLRP12 expression in SLE patients was also analyzed. Bone marrow derived dendritic cells (BMDCs) were collected from wild type mouse and Nlrp12 knocked-out mice. Another CD14+ monocytes were isolated from 10 cases of lupus patients and 8 cases of healthy control, following by stimulating different type of nucleic acids, and IFN-α and IL-6 were measured with ELISA assay. CD14+ monocytes in lupus patients were also pre-treated with IFNAR2 antibody for further nucleic acid stimulation. Two mice models were applied for evaluation the role of Nlrp12: intraperitoneal injection of TMPD (2,6,10,14-tetramethylpentadecane, or pristane) in C57BL/6 mice and Faslpr mice. Both models were conducted with and without Nlrp12 knockout.Results:NLRP12 expression was significantly lower in PBMC isolated from SLE patients compared to healthy donors. The inverse correlation was observed in NLRP12 and IFNA gene expression as well as NLRP12 expression and amount of double-stranded DNA autoantibody in SLE patients. NLRP12 expression showed negative correlations with IFN-α treatment, as well as herpes simplex virus-1 (HSV-1) infection. Results from ChIP and EMSA analysis indicated a potential transcription factor 1 (TF-1) regulating NLRP12 promoter activity. TF-1 lead to transcriptional suppression of NLRP12 in SLE PBMC, and it was gradually induced after IFN treatment. Recruitment of TF-1 to NLRP12 promoter in SLE PBMC compared to the healthy PBMC was detected, and increased when treating with IFN. Human CD14+ monocytes collected from lupus and healthy control stimulating with different type of nucleic acids revealing significant increasing level of IFN-α and IL-6 in lupus patients. Among animal models, both pristine induced mice and Faslpr mice revealed increasing autoantibodies production and severity of glomerulonephritis in Nlrp12-/- group in comparison with Nlrp12+/+ ones, indicating the role of NLRP12 in maintaining positive interferon signature as well as disease activity.Conclusion:Expression level of NLRP1.2 has been demonstrated to be a biomarker of disease activity in SLE patients. The NLRP12 was involved in the interferon signature, which was also negatively regulated by TF-1. Both clinical samples and animal models revealed NLRP12 in maintaining the positive interferon signature, indicating the possible role of exacerbating factor for lupus disease activity.Disclosure of Interests:None declared


2021 ◽  
Vol 12 (7) ◽  
Author(s):  
Ian Edward Gentle ◽  
Isabel Moelter ◽  
Mohamed Tarek Badr ◽  
Konstanze Döhner ◽  
Michael Lübbert ◽  
...  

AbstractMutations in the transcription factor C/EBPα are found in ~10% of all acute myeloid leukaemia (AML) cases but the contribution of these mutations to leukemogenesis is incompletely understood. We here use a mouse model of granulocyte progenitors expressing conditionally active HoxB8 to assess the cell biological and molecular activity of C/EBPα-mutations associated with human AML. Both N-terminal truncation and C-terminal AML-associated mutations of C/EBPα substantially altered differentiation of progenitors into mature neutrophils in cell culture. Closer analysis of the C/EBPα-K313-duplication showed expansion and prolonged survival of mutant C/EBPα-expressing granulocytes following adoptive transfer into mice. C/EBPα-protein containing the K313-mutation further showed strongly enhanced transcriptional activity compared with the wild-type protein at certain promoters. Analysis of differentially regulated genes in cells overexpressing C/EBPα-K313 indicates a strong correlation with genes regulated by C/EBPα. Analysis of transcription factor enrichment in the differentially regulated genes indicated a strong reliance of SPI1/PU.1, suggesting that despite reduced DNA binding, C/EBPα-K313 is active in regulating target gene expression and acts largely through a network of other transcription factors. Strikingly, the K313 mutation caused strongly elevated expression of C/EBPα-protein, which could also be seen in primary K313 mutated AML blasts, explaining the enhanced C/EBPα activity in K313-expressing cells.


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