scholarly journals Cucurbit chlorotic yellows virus p22 suppressor of RNA silencing binds single-, double-stranded long and short interfering RNA molecules in vitro

2020 ◽  
Vol 279 ◽  
pp. 197887
Author(s):  
Ferran Salavert ◽  
José Antonio Navarro ◽  
Carolyn A. Owen ◽  
Souheyla Khechmar ◽  
Vicente Pallás ◽  
...  
2008 ◽  
Vol 149 (4) ◽  
pp. 153-159 ◽  
Author(s):  
Zsuzsanna Rácz ◽  
Péter Hamar

A genetikában új korszak kezdődött 17 éve, amikor a petúniában felfedezték a koszuppressziót. Később a koszuppressziót azonosították a növényekben és alacsonyabb rendű eukariótákban megfigyelt RNS-interferenciával (RNSi). Bár a növényekben ez ősi vírusellenes gazdaszervezeti védekezőmechanizmus, emlősökben az RNSi élettani szerepe még nincs teljesen tisztázva. Az RNSi-t rövid kettős szálú interferáló RNS-ek (short interfering RNA, siRNS) irányítják. A jelen cikkben összefoglaljuk az RNSi történetét és mechanizmusát, az siRNS-ek szerkezete és hatékonysága közötti összefüggéseket, a célsejtbe való bejuttatás virális és nem virális módjait. Az siRNS-ek klinikai alkalmazásának legfontosabb akadálya az in vivo alkalmazás. Bár a hidrodinamikus kezelés állatokban hatékony, embereknél nem alkalmazható. Lehetőséget jelent viszont a szervspecifikus katéterezés. A szintetizált siRNS-ek ismert mellékhatásait szintén tárgyaljuk. Bár a génterápia ezen új területén számos problémával kell szembenézni, a sikeres in vitro és in vivo kísérletek reményt jelentenek emberi betegségek siRNS-sel történő kezelésére.


2008 ◽  
Vol 82 (23) ◽  
pp. 11851-11858 ◽  
Author(s):  
Vitantonio Pantaleo ◽  
József Burgyán

ABSTRACT Cymbidium ringspot virus (CymRSV) satellite RNA (satRNA) is a parasitic subviral RNA replicon that replicates and accumulates at the cost of its helper virus. This 621-nucleotide (nt) satRNA species has no sequence similarity to the helper virus, except for a 51-nt-long region termed the helper-satellite homology (HSH) region, which is essential for satRNA replication. We show that the accumulation of satRNA strongly depends on temperature and on the presence of the helper virus p19 silencing suppressor protein, suggesting that RNA silencing plays a crucial role in satRNA accumulation. We also demonstrate that another member of the Tombusvirus genus, Carnation Italian ringspot virus (CIRV), supports satRNA accumulation at a higher level than CymRSV. Our results suggest that short interfering RNA (siRNA) derived from CymRSV targets satRNA more efficiently than siRNA from CIRV, possibly because of the higher sequence similarity between the HSH regions of the helper and CIRV satRNAs. RNA silencing sensor RNA carrying the putative satRNA target site in the HSH region was efficiently cleaved when transiently expressed in CymRSV-infected plants but not in CIRV-infected plants. Strikingly, replacing the CymRSV HSH box2 sequence with that of CIRV restores satRNA accumulation both at 24°C and in the absence of the p19 suppressor protein. These findings demonstrate the extraordinary adaptation of this virus to its host in terms of harnessing the antiviral silencing response of the plant to control the virus parasite satRNA.


2005 ◽  
Vol 57 (1) ◽  
pp. 122-126 ◽  
Author(s):  
Katsunori Yanagihara ◽  
Miwa Tashiro ◽  
Yuichi Fukuda ◽  
Hideaki Ohno ◽  
Yasuhito Higashiyama ◽  
...  

Endocrinology ◽  
2008 ◽  
Vol 149 (9) ◽  
pp. 4702-4709 ◽  
Author(s):  
Erik R. Nelson ◽  
Hamid R. Habibi

Thyroid hormones are important mediators of growth and development in vertebrates and act by binding to a specific family of thyroid receptors (TRs). The TRs belong to the nuclear receptor superfamily, with two conserved regions, a DNA binding domain and a ligand binding domain (LBD). We recently demonstrated the presence of four TR subtypes in goldfish, two with complete DNA binding domains and LBDs (TRα-1 and TRβ) and two novel forms including a transcript resembling TRα with variation in the LBD as well as a TRα-truncated (TRα-t) form lacking a LBD. To study the functional significance of TR subtypes, we first investigated the regulation of hepatic goldfish deiodinase type 3 (D3) by T3 and validated a bioassay in which D3 gene expression is up-regulated significantly in vivo and in vitro. Using short interfering RNA, TRα-1, TRβ, or TRα-t was specifically knocked down and thyroid hormone-induced D3 gene expression was measured. short interfering RNA against TRα-1 or TRβ reduced the T3 induction of deiodinase gene expression to 50% or less than 25% of control (T3 treated) cells, respectively. Knocking down TRα-t alone, however, increased D3 expression 500-fold supporting the hypothesis that TRα-t plays a modulatory role in thyroid hormone-induced gene expression. Our results provide important insight into thyroid receptor biology in goldfish and a framework for the better understanding of thyroid receptor function in all vertebrates.


Biomedicines ◽  
2020 ◽  
Vol 8 (12) ◽  
pp. 612
Author(s):  
Saffiya Habib ◽  
Mario Ariatti ◽  
Moganavelli Singh

Overexpression of the c-myc proto-oncogene features prominently in most human cancers. Early studies established that inhibiting the expression of oncogenic c-myc, produced potent anti-cancer effects. This gave rise to the notion that an appropriate c-myc silencing agent might provide a broadly applicable and more effective form of cancer treatment than is currently available. The endogenous mechanism of RNA interference (RNAi), through which small RNA molecules induce gene silencing by binding to complementary mRNA transcripts, represents an attractive avenue for c-myc inhibition. However, the development of a clinically viable, anti-c-myc RNAi-based platform is largely dependent upon the design of an appropriate carrier of the effector nucleic acids. To date, organic and inorganic nanoparticles were assessed both in vitro and in vivo, as carriers of small interfering RNA (siRNA), DICER-substrate siRNA (DsiRNA), and short hairpin RNA (shRNA) expression plasmids, directed against the c-myc oncogene. We review here the various anti-c-myc RNAi-based nanosystems that have come to the fore, especially between 2005 and 2020.


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