scholarly journals The C2H2 Transcription Factor REGULATOR OF SYMBIOSOME DIFFERENTIATION Represses Transcription of the Secretory Pathway Gene VAMP721a and Promotes Symbiosome Development in Medicago truncatula

2013 ◽  
Vol 25 (9) ◽  
pp. 3584-3601 ◽  
Author(s):  
Senjuti Sinharoy ◽  
Ivone Torres-Jerez ◽  
Kaustav Bandyopadhyay ◽  
Attila Kereszt ◽  
Catalina I. Pislariu ◽  
...  
2021 ◽  
Vol 8 (1) ◽  
Author(s):  
Xiaolong Hao ◽  
Chenhong Xie ◽  
Qingyan Ruan ◽  
Xichen Zhang ◽  
Chao Wu ◽  
...  

AbstractThe limited bioavailability of plant-derived natural products with anticancer activity poses major challenges to the pharmaceutical industry. An example of this is camptothecin, a monoterpene indole alkaloid with potent anticancer activity that is extracted at very low concentrations from woody plants. Recently, camptothecin biosynthesis has been shown to become biotechnologically amenable in hairy-root systems of the natural producer Ophiorrhiza pumila. Here, time-course expression and metabolite analyses were performed to identify novel transcriptional regulators of camptothecin biosynthesis in O. pumila. It is shown here that camptothecin production increased over cultivation time and that the expression pattern of the WRKY transcription factor encoding gene OpWRKY2 is closely correlated with camptothecin accumulation. Overexpression of OpWRKY2 led to a more than three-fold increase in camptothecin levels. Accordingly, silencing of OpWRKY2 correlated with decreased camptothecin levels in the plant. Further detailed molecular characterization by electrophoretic mobility shift, yeast one-hybrid and dual-luciferase assays showed that OpWRKY2 directly binds and activates the central camptothecin pathway gene OpTDC. Taken together, the results of this study demonstrate that OpWRKY2 acts as a direct positive regulator of camptothecin biosynthesis. As such, a feasible strategy for the over-accumulation of camptothecin in a biotechnologically amenable system is presented.


2010 ◽  
pp. no-no ◽  
Author(s):  
Qiao Zhao ◽  
Lina Gallego-Giraldo ◽  
Huanzhong Wang ◽  
Yining Zeng ◽  
Shi-You Ding ◽  
...  

Traffic ◽  
2013 ◽  
Vol 14 (4) ◽  
pp. 382-398 ◽  
Author(s):  
Sónia Barbosa ◽  
Giovanna Fasanella ◽  
Suzanne Carreira ◽  
Marta Llarena ◽  
Rebecca Fox ◽  
...  

2000 ◽  
Vol 66 (5) ◽  
pp. 2062-2065 ◽  
Author(s):  
Lifeng Chen ◽  
Susan P. McCormick ◽  
Thomas M. Hohn

ABSTRACT Most Fusarium graminearum isolates produce low or undetectable levels of trichothecenes in liquid shake cultures, making it difficult to perform biochemical studies of trichothecene biosynthesis. To develop strains with higher levels of trichothecene production under liquid shake conditions we transformed F. graminearum with both a reporter gene containing a homologous trichothecene pathway gene promoter (TRI5) and a gene encoding a heterologous trichothecene pathway transcription factor (TRI6). The TRI5 and TRI6 genes are part of the trichothecene pathway gene clusters of both Fusarium sporotrichioides and F. graminearum. These genes encode trichodiene synthase (encoded by TRI5), the first enzyme in the trichothecene pathway, and a transcription factor (encoded by TRI6) required for pathway gene expression. Transformation of F. graminearum with plasmids containing either an F. graminearum TRI5 promoter fragment (FGTRI5P ) or FGTRI5P coupled with the β-d-glucuronidase (GUS) reporter gene resulted in the identification of several transformants capable of producing 45 to 200 mg of 15-acetyldeoxynivalenol (15-ADON)/liter in liquid shake culture after 7 days. Increased 15-ADON production was only observed in transformants where plasmid integration occurred through the FGTRI5P sequence and was not accompanied by increased GUS expression. 15-ADON production was further increased in liquid culture up to 1,200 mg/liter following introduction of the F. sporotrichioides TRI6 gene (FSTRI16) into F. graminearum. The effects of FSTRI6 on 15-ADON production also depended on plasmid integration via homologous recombination of the FGTRI5P fragment and resulted in a 100-fold increase in GUS expression. High-level production of 15-ADON in liquid shake cultures provides a convenient method for large-scale trichothecene preparation. The results suggest that targeting transformation vector integration toFGTRI5P alters pathway gene expression and are consistent with the proposed conservation of TRI6 function betweenFusarium species.


2021 ◽  
Vol 220 (8) ◽  
Author(s):  
Ioanna Pitsidianaki ◽  
Jason Morgan ◽  
Jamie Adams ◽  
Kyra Campbell

Mesenchymal-to-epithelial transition (MET) converts cells from migratory mesenchymal to polarized epithelial states. Despite its importance for both normal and pathological processes, very little is known about the regulation of MET in vivo. Here we exploit midgut morphogenesis in Drosophila melanogaster to investigate the mechanisms underlying MET. We show that down-regulation of the EMT transcription factor Serpent is required for MET, but not sufficient, as interactions with the surrounding mesoderm are also essential. We find that midgut MET relies on the secretion of specific laminins via the CopII secretory pathway from both mesoderm and midgut cells. We show that secretion of the laminin trimer containing the Wingblister α-subunit from the mesoderm is an upstream cue for midgut MET, leading to basal polarization of αPS1 integrin in midgut cells. Polarized αPS1 is required for the formation of a monolayered columnar epithelium and for the apical polarization of αPS3, Baz, and E-Cad. Secretion of a distinct LamininA-containing trimer from midgut cells is required to reinforce the localization of αPS1 basally, and αPS3 apically, for robust repolarization. Our data suggest that targeting these MET pathways, in conjunction with therapies preventing EMT, may present a two-pronged strategy toward blocking metastasis in cancer.


1997 ◽  
Vol 328 (1) ◽  
pp. 69-74 ◽  
Author(s):  
Erik JANSEN ◽  
A. Y. Torik AYOUBI ◽  
M. P. Sandra MEULEMANS ◽  
Wim J. M. VAN DE VEN

Prohormone convertases are involved in the tissue-specific endoproteolytic processing of prohormones and neuropeptide precursors within the secretory pathway. In the present study, we have isolated genomic clones comprising the 5ʹ-terminal region of the human prohormone convertase 2 (PC2) gene and established characteristics of the PC2 promoter region. The proximal promoter region is very G+C-rich and does not contain a canonical TATA box or a CAAT box. Transient expression assays with a set of human PC2 gene fragments containing progressive 5ʹ deletions demonstrate that the proximal promoter region is capable of directing high levels of neuroendocrine-specific expression of reporter gene constructs. In addition, we show that the transcription factor EGR-1 interacts with two distinct elements within the proximal human PC2 promoter region. Transfection experiments also demonstrate that EGR-1 is able to enhance PC2 promoter activity.


2020 ◽  
Vol 295 (30) ◽  
pp. 10406-10419 ◽  
Author(s):  
Akira Hosomi ◽  
Kazuko Iida ◽  
Toshihiko Cho ◽  
Hidetoshi Iida ◽  
Masashi Kaneko ◽  
...  

Soluble proteins destined for the secretory pathway contain an N-terminal signal peptide that induces their translocation into the endoplasmic reticulum (ER). The importance of N-terminal signal peptides for ER translocation has been extensively examined over the past few decades. However, in the budding yeast Saccharomyces cerevisiae, a few proteins devoid of a signal peptide are still translocated into the ER and then N-glycosyl-ated. Using signal peptide-truncated reporter proteins, here we report the detection of significant translocation of N-terminal signal peptide-truncated proteins in a yeast mutant strain (ste24Δ) that lacks the endopeptidase Ste24 at the ER membrane. Furthermore, several ER/cytosolic proteins, including Sec61, Sec66, and Sec72, were identified as being involved in the translocation process. On the basis of screening for 20 soluble proteins that may be N-glycosylated in the ER in the ste24Δ strain, we identified the transcription factor Rme1 as a protein that is partially N-glycosylated despite the lack of a signal peptide. These results clearly indicate that some proteins lacking a signal peptide can be translocated into the ER and that Ste24 typically suppresses this process.


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